Joulary help

The home screen

The app has four tabs along the bottom: Home, Timeline, Analytics and Settings. Home is a stack of cards — Energy, Climate and Energy savings — each a live summary that updates on its own as the car reports in. Tapping a card's title row expands it; tapping again collapses it. A card that has had nothing reported to it yet shows grey placeholder lines with Waiting for the car to report… beneath them (Working out your savings… on the savings card), which is normal in the first minutes after setting up. Before your car and energy supplier are connected, the Energy and Climate cards say so in place of their readings and offer a Go to Settings link, and the Energy savings card is not there at all. Pulling down on the screen refreshes everything: the app reconnects and fetches the whole picture afresh. A reading the app cannot make sense of shows Unavailable in its place, and a card that cannot be shown at all is replaced by its name and Unavailable — Energy: Unavailable, for instance — while the rest of the screen carries on. It clears by itself once a readable value arrives; when it keeps coming back, updating the app to its latest version usually fixes it.

The notifications card

Once your connections are set up, a card headed Get alerted when the car should be plugged in sits at the top of Home until you answer it. Enable notifications opens the phone's own permission question; Not now puts the card away for a month. Once the permission is granted the card is gone; if you declined it, the card reads Notifications are off and offers Open Settings, since the phone's own settings are where a declined permission is turned on. What the notifications say, and what declining changes, is covered in the notifications help.

The Energy card

The most detailed card, and the one that answers "what is my car doing right now?".

• The title row carries a Smart: badge showing the charging mode — Long Term, Short Term, Off, or Paused with the time the pause ends, such as "Paused until 14:30". A red alert icon appears beside it when planning has hit a problem; expanding the card shows the reason.
• The state line says what the car itself reports: Charging (with a pulsing icon), Idle — which covers a car that has finished at its charge limit as well as one simply sitting there — No Power (the cable is in but the charger is giving nothing), or Offline (the car is asleep or unreachable). Next to it, an At home pill appears when the car is at your home location, and a Plugged in or Unplugged pill shows the cable state.
• The battery line shows the current charge percentage. In Short Term mode it also shows the goal, e.g. "62% → 80% by 07:00" — your Charge To level by your Ready By time.
• The status line relates what is happening to the plan:
  • Charging will start at … — a charge is booked and the car is ready for it.
  • Plug in by … — a charge is booked but the cable is not in yet.
  • Charging will stop at … — the current charge is part of the plan, and this is when it ends.
  • Unscheduled charging — the car is charging outside any planned slot, usually because charging was started by hand.
  • Should be charging — a planned charge ought to be running and is not; the app is working on it.
  • Could be charging if it were at home — a planned charge is due, but the car is elsewhere.
• A warning strip — "Plug in — should be charging now" — appears when the car is at home and unplugged while the plan wants to charge. This is the moment plugging in actually matters.
• The action button offers Charge now when the car is idle, plugged in at home and able to charge — starting a charge by hand is covered in the manual-charging help. While the pause after a manual stop is in effect, the same spot offers Resume smart charging, which hands control straight back. After a Charge now is accepted, a progress note takes the button's place — "Charge to 80% requested — waking the car…" and then "starting…" — until the charge begins.
• Your charge targets appear at the bottom of the card in Long Term mode: a ribbon of the upcoming ones, or a short introduction when you have none yet. With more than one, dots beneath the ribbon mark which target you are looking at — a count once there are more than eight — and a Next button appears once you move off the soonest, to bring you back to it. What a charge target is, and how to create one, is covered in the charge-targets help.

Expanding the Energy card

Expanding shows the reading in full: car state, cable and home status, exact charge percentage, the smart-charging mode, the measured average Charge power and Charge speed, the measured Consumption (battery percent per mile driven) and Vampire drain over 3h (the battery a three-hour stop away from home costs), whether the plan currently calls for charging, and — in Short Term mode — the target and ready-by values. A figure the app has not yet gathered enough of your history to measure is shown greyed with (calibrating) beside it, and the starting figure it is using until then. Below that sits the Schedule table: every planned charging block, grouped by day, with the charge each block adds, its average electricity price, and its estimated cost, plus a Total row. The cost figures come from the block's prices and your car's measured charging power. Under the Total row, in Long Term mode, a line says where the plan's highest point sits — Stops at your "Keep charge lower than" level or Stops below your "Keep charge lower than" level — which the smart-charging help explains. Beside each block's times sits a short note saying why the app put it there — charge to, min charge, trip, target, yummy or super yummy; what each of those means is covered in the smart-charging help. In Short Term mode every block reads charge to, since that is the whole of what that mode is doing. A block that serves two purposes at once shows both, as in trip, yummy. When planning has hit a problem, a red Problem line states the reason — it clears once planning recovers.

The expanded view is also a history. Swipe the open card sideways — or tap the arrows at its edges — to move through the last 40 readings; each page is headed As of with the time it was taken, and pages behind the newest carry a Historical badge. A row of dots underneath marks which reading you are on, giving way to a count once there are more than eight. The newest page follows live updates on its own, and a Latest button appears beside the dots as soon as you move off it; double-tapping the card goes back there too.

The Climate card

A glance at the cabin: whether climate control is On or Off, the temperature inside the car, and the target temperature it is set to. Expanding it adds the time the temperature reading was taken and swipes through past readings the same way as the Energy card.

Under those readings is a line saying what the app is doing about the cabin before your next trip, and it is the quickest way to find out why the climate is or is not running: Preconditioning for your trip while a run is under way, Will precondition before your trip once a trip is close enough and the app is waiting for the right moment, or one of the reasons it is doing nothing — Cabin already close to your target, You are running the climate, No trip coming up, Next trip is too far ahead, Next trip is marked /noc, Car is away from home, No temperature to work from, or Waiting for information it needs while something the decision rests on has yet to arrive. Each of them is explained in the preconditioning help, which also covers when the app decides to run at all. Expanding the card shows the same line for every past reading, so you can see what it was doing earlier.

The Energy savings card

A glance at what smart charging is saving you. It appears once your energy supplier is connected, and covers the period chosen by your Savings period for home screen setting, shown in the card's corner. The headline is Saved (green) or Extra (red) with the amount and percentage, above the two totals it compares: You paid and Ref — what the same energy would have cost on Intelligent Octopus Go, the reference tariff. Expanding the card shows the full cost table; the Analytics tab has the same comparison over any period you choose, with a daily breakdown. If the figures are slow in coming, the card says so after a couple of minutes — "Your savings are taking longer than usual to work out. The app is still trying." — and it keeps asking, so the figures appear by themselves once they arrive. What the figures mean, and why a period can show "Cost comparison unavailable", is covered in the savings help.

The Reconnecting and Offline notices

When the app loses its connection for more than a few seconds, a Reconnecting… strip appears along the bottom of the screen. If the connection stays lost for half a minute the strip turns amber and reads Offline – showing data from with the time the last reading arrived, so you can tell how old the picture is. What is on screen stays put either way — it is simply the last known picture — and everything refreshes by itself once the connection returns.

The settings screen

The Settings tab is a row of tab pills — which tabs you see comes from what your account has — with the chosen tab's content below. A small warning triangle on a pill means something behind it needs attention: an integration that stopped working, a missing home location, a calendar that appeared since you last chose which calendars to use, or a car that another Joulary account already controls. Until every required connection is set up, the screen opens on the Integrations tab with a notice — "Please configure all the required integrations" — because the app can do nothing until they are. Before your settings have arrived the screen shows grey placeholder shapes where the pills and rows will be, and pulling down on a tab's content refreshes them.

The Integrations tab

Three cards: Energy Provider, Cars and Calendars. Each card's corner tells its state at a glance: a green tick means it is working, a small spinner means the app is still checking what you entered, and a warning icon means it needs your attention — red when the connection is not working or not set up, amber when it works but something is worth reviewing (for the Cars card, that is the ownership conflict described in the car-connection help).

• Adding a connection. The Energy Provider card offers a set-up button naming the supplier — Octopus Energy is the only supplier currently supported — which opens the credentials screen described below. The Cars and Calendars cards use a dashed + button; when more than one provider is available a chooser appears (Select car brand / Select calendar provider).
• Each configured connection is shown with its own tick, spinner or warning icon, and a bin icon that removes it after a confirmation question — for example "Log out of your Tesla account?" or "Disconnect your Google Calendar?".
• When stored details stop working, the card says so — for instance "Unable to authenticate with Octopus Energy. Re-enter your account details." — and for suppliers and calendars that use typed credentials, offers a Re-enter credentials button. That opens the credentials screen: a separate small screen headed with the connection's name — Octopus Energy or Apple iCloud — where the details are typed and saved: your account details for Octopus Energy, or your Apple ID and app-specific password for an Apple iCloud calendar. Connections made by signing in — Google Calendar, Tesla — are repaired by signing in again on their card instead. What each integration needs, and what the app does with it, is covered in the energy supplier, car-connection and calendar help.

The Car tab

Car settings are grouped into sections — Charging, Climate, and Other — each shown as a card with a count of the settings inside; tapping one opens its list. The charging list adapts to your Car Smart Charge Mode setting, which always sits first: settings that have no effect in the current mode are hidden, so the count changes as you switch modes.

Reading and editing a setting

Every setting is a row: its name, a one-line description, and its current value, with more rows behind the section cards above. Tapping a row opens the setting's own screen, headed by a fuller explanation of what it does, then the editor:

• Switches, choices, times and pickers apply on their own a moment after you change them — there is nothing to press.
• Sliders save shortly after you stop moving them.
• Typed values — text and durations — have a Save button.
• Going back saves an edit: anything not yet saved — a typed value you did not press Save for, an edited charge-target list — is sent for saving as you leave the screen. Two edits are held back. A charge-target list the app can already see is incomplete, say a target with no name or no day, cannot be sent: leaving then asks Discard changes?, with Keep editing and Discard. And your home location is only ever saved by its Save button, because the map picks whatever sits under the pin as you move it, and looking around should not move your home.

If the app cannot read a setting's saved value, the row shows Unavailable as its value, and the setting's screen shows Unavailable in place of the editor, with nothing to change or save — so the saved value stays exactly as it was. The Energy Provider card does the same: when the app cannot read the supplier connection you saved, the card shows Energy Provider: Unavailable and offers no set-up button, so the saved connection is left as it is.

The value shown after saving is the app's tidied version of what you entered. If a value cannot be accepted while you are still on the setting's screen, the screen says so and keeps what you typed so you can correct it; the previously saved value stays in effect until a new one is accepted. Usually it can say what to enter instead — a whole number, a length of time, a percentage within a range — and where it cannot, it says only that the value cannot be saved. If a save fails after you have left the screen, a Couldn't save notice naming the setting appears along the bottom of Settings: for a value the server would not accept it carries the same explanation and an Edit button that reopens the setting, and for a save the server never answered — the connection dropped, say — a Retry button. The same connection failure while you are still on the screen shows a Problem saving settings card with its own Retry. A changed setting takes effect immediately — the plan and the cards reflect it on the next update.

How smart charging works

Smart charging decides when your car draws power, so you pay as little as possible for the electricity you need. Plugging in is all you have to do: the app waits for cheap slots instead of charging straight away, so a freshly plugged-in car sitting idle is normal, not a fault.

The three modes

• Long Term — the default, and the one everything below describes. It plans across the whole period prices are published for, taking account of trips it found in your calendar, the charge targets you set, and how cheap each slot is.
• Short Term — a simple promise: reach your Charge To level by your Ready By time, at the cheapest slots in between. It ignores calendar trips and cheap-price opportunities beyond that one deadline. Ready By is a time of day (9 in the morning unless you change it), and it always means the next time that clock time comes round — set 07:00 at 8am and you have asked for tomorrow morning.
• Disabled — the app plans nothing and leaves the car alone.

How a plan is built

The app keeps a running picture of the battery's future: what each trip will take out of it, what each planned charge will put in, and what level it will be at from moment to moment. The plan is built by laying five kinds of demand onto that picture in a strict order — most binding first, so nothing added later can break a promise already made:

1. Trips are blocked out first. Each trip it knows about is marked as time no charging can use — you are driving — and as a drop in charge of the size the trip is expected to spend.
2. Keeping the battery above your floor. If charge has fallen below Keep charge higher than, that debt is repaid before anything else is considered, so later additions cannot push the repayment past a ceiling. The details are in the next section.
3. Enough charge for each trip. For every trip, in departure order, the app checks what level the picture predicts at departure against what the trip needs — your floor plus what the trip itself will spend — and, if the gap is more than about one percentage point, schedules charging beforehand to close it. A gap within a point is left alone: chasing fractions of a percent would rewrite the plan constantly for nothing you could notice.
4. Your charge targets, in the same way, but with the target level scaled by how sure you said you were you need each occurrence.
5. Cheap-slot opportunism last. Only after every promise is banked does the app fill remaining cheap slots up to your ceilings, so a bargain can never displace charge a trip depends on. It works from the higher of the two ceilings down, and after each addition it re-checks the whole picture for a new high point before adding more — which is how it fills around peaks without ever cresting a ceiling.

The order is the point: each step tops up relative to everything already planned, so charge added for Monday's trip also counts towards Tuesday's target, and nothing is ever charged twice.

Each block remembers which of those steps put it there, and the Schedule table on the expanded Energy card prints it beside the block's times:

• charge to — reaching your Charge To level by your Ready By time. This is the whole of a Short Term plan, so in that mode every block says it.
• min charge — repaying a dip below your Keep charge higher than level.
• trip — charge a trip in your calendar needs.
• target — charge one of your charge targets needs.
• yummy — a slot taken because its price is at or below your Yummy Price.
• super yummy — a slot taken because its price is at or below your Super Yummy Price.

Four of them name a setting you can change — charge to your Charge To, min charge your Keep charge higher than, yummy your Yummy Price and super yummy your Super Yummy Price — so the note tells you which number to adjust if you disagree with the block. trip and target instead name what asked for the charge: the calendar entry the app is getting you ready for, or the charge target you set.

The first four are promises and the last two are bargains, which is the distinction the order above is built on: a trip block stays in the plan whatever happens to prices, while a yummy one is only there while the slot is worth taking. Tidying can join two neighbouring blocks into one, and the joined block then carries both notes — trip, yummy means the app needed that charge for a trip and the slots it landed on were cheap ones.

Keeping the battery above your floor

Dipping below Keep charge higher than starts a clock: the app allows itself your Can stay below min charge for setting to put the charge back, measured from the moment the battery first dipped — and that moment is remembered, so the deadline holds steady however many times the plan is rebuilt. While the deadline is still ahead, the repayment shops across the whole time up to it for the cheapest slots. Once the deadline has passed, the app stops being fussy: it takes the earliest slots available, whatever they cost, because the floor is now overdue. And when a trip departs before the repayment is due, the trip's own charging absorbs the job — charging for the trip already brings the battery up past the floor.

Topping up for a trip or a target

When a trip or a target needs more charge than the picture predicts it will have, the app looks for that charge in up to three passes, each more permissive than the last:

1. Up to your everyday ceiling (Keep charge lower than), using the cheapest slots before the departure, at any price — a promise beats a bargain.
2. On to your Super Yummy Max SoC ceiling, but only in slots at or below your Super Yummy Price — reaching above the everyday ceiling is allowed early only when the electricity is genuinely cheap.
3. On to 100%, at any price, but only in the window immediately before the departure — the length of that window is your Charge to full no earlier than setting. Charging the battery right up is sometimes the only way to make a long trip, and doing it at the last moment keeps the time spent brim-full short, which preserves your battery health.

The last pass is deliberately a timing rule and not a wear allowance: it runs when you would otherwise arrive short, and getting you there wins. Allow SoC above Super Yummy Max, described below, governs the separate case where the app fills past the ceiling only because electricity is unusually cheap — that one is optional, so it is budgeted, and the plan must bring the battery back to the ceiling by the time it ends.

Each pass only runs if the previous ones left a shortfall, so on most days only the first ever happens.

The two price thresholds

This is the part that surprises people most, because it means the app will happily charge when you have not asked it to.

• Slots at or below your Yummy Price are used to charge up to Keep charge lower than.
• Slots at or below your Super Yummy Price — the rarer, deeper bargains — are used to charge further, up to your Super Yummy Max SoC.

Sitting at a very high charge wears the battery, so going above that higher ceiling is budgeted, not free. The app adds up the wear the whole plan — including the recent past — puts on the battery above the ceiling, and allows super-cheap charging beyond it while that total stays within your Allow SoC above Super Yummy Max setting. Wear the battery has already taken up there counts against the budget, so a generous boost yesterday genuinely reduces what today's plan will allow.

Going above the cap is a trip up and back down, never a new resting level, so there is a second condition: the plan must bring the battery back to your Super Yummy Max SoC by the time it ends, which in practice means a journey has to spend the extra charge. When nothing in the plan would bring it down again — a quiet week with no trips, say — the app fills to your Super Yummy Max SoC and stops there, however cheap the electricity is. Parking the battery above your cap and leaving it there would go on wearing it for as long as the car sat unused, and no allowance can cover that.

The allowance is a budget, not a stopwatch. Setting Allow SoC above Super Yummy Max to twelve hours does not mean "the battery may be above the cap for twelve hours" — it means "the battery may take as much wear as twelve hours at 100% would cause". Those are very different amounts of time, because how quickly the allowance is spent depends on how high the charge is, not only on how long it stays there.

The rule is that sitting twice as far above the cap wears the battery four times as fast, so the allowance drains quickly near 100% and very slowly just above the cap. Take a cap of 85% and an allowance of 12 hours. At 100% — the full 15 points above the cap — an hour of sitting spends an hour of allowance, so the whole allowance is gone in half a day. At 92.5%, half way up, an hour spends only a quarter of an hour of allowance, so the same 12 hours stretches to two days. At 89%, a quarter of the way up, an hour costs about four minutes, which lasts a week. And at 86% — one point above the cap — an hour costs sixteen seconds, so a whole week spent a point over barely dents the allowance.

So a brief fill to 100% before a long trip is affordable, and so is a small excursion held for days, while a battery kept at 100% spends the same allowance many times faster. That is the point of budgeting wear and not time: the two are genuinely different for the battery, and treating them the same would either forbid the harmless one or permit the harmful one. What the allowance never buys is a permanent stay above the cap, which is what the second condition above rules out.

Two other things move the same allowance:

• How long the battery stays high, straightforwardly: twice the time at the same level is twice the wear.
• How cold it is. Batteries age more slowly when cold, so a frosty night stretches the allowance and a hot spell shrinks it. The app uses the forecast for your home area, which is why the same plan can be allowed in January and refused in July.

If your car's maker recommends charging to 100% — as several standard-range cars with lithium iron phosphate batteries do, because that chemistry prefers being filled regularly — set Super Yummy Max SoC to 100%. Nothing is then above the ceiling, the allowance stops applying, and cheap charging can fill the battery whenever the price is right.

Why the plan stops where it does

Expand the Energy card and, in Long Term mode with charging in the plan, a line under the Schedule total says where the plan's highest point sits against your Keep charge lower than level:

• Stops at your "Keep charge lower than" level — the plan fills up to that level and no further. Going above it is reserved for slots at or below your Super Yummy Price, up to your Super Yummy Max SoC, so raise Keep charge lower than if you want more charge at everyday prices, and look at those two settings if you expected the cheap slots to carry it higher.
• Stops below your "Keep charge lower than" level — the plan would have charged more and the days ahead held too few slots it could use. A slot is usable when it is priced at or below your Yummy Price or Super Yummy Price and you are not driving then, so either raising a threshold or a quieter week gives the plan more to work with.

The two answer quite different questions, which is why the line is worth reading before changing a setting: raising a price threshold does nothing when the plan already reached your level, and raising the level does nothing when there were too few usable slots to fill it with.

When the plan has no charging in it at all, the Schedule table is not drawn and neither is this line; why a plan can hold nothing is the next section. A plan that charges past your Keep charge lower than level — for a trip, a charge target, or a run of very cheap slots — has no line either, because then the level is not what the plan stopped at. Neither does a Short Term plan, which works to the Charge To level you set, not to your everyday ceiling.

When no charging is planned

In Long Term mode, a plan with no charging in it usually means every step of building it found nothing to do:

• Your charge is above your "Keep charge higher than" level, so there is no dip to repay.
• Every trip ahead is already covered. The charge the plan expects at each departure already reaches your floor plus what the trip will spend, which the Timeline chart shows as each trip leaving with charge to spare.
• Any charge target in the days ahead is already met by the charge the car is expected to have.
• No slot the plan could use is cheap enough to fill, or the battery is already where cheap charging would take it. Nothing it could charge in is priced at or below your Yummy Price while the charge sits below your Keep charge lower than level, and nothing at or below your Super Yummy Price while it sits below your Super Yummy Max SoC. A cheap slot while you are driving, or one shorter than your Do not plan slots shorter than setting, is not one it could use.

An empty plan can still leave something to come. A trip or charge target beyond the published prices is not planned yet, and enters the plan when prices reach it. A trip that needs charging away from home ends the plan there, and a charge target that falls during a trip is ignored in favour of the trip. If a trip still comes up short, the Charge shortfall notification says so.

So the usual reason is simply that the car has enough charge for everything ahead and the electricity is not cheap enough to be worth more. Charging appears as soon as one of those changes: a new trip in your calendar, a charge target, a higher Yummy Price, or cheaper prices arriving for the days ahead.

Where the car is and whether it is plugged in play no part in this. The app plans the same way while the car is away from home or unplugged; the cable decides only whether a planned block can actually charge, which is when the app asks you to plug in. An empty plan therefore says nothing about the car being out — it says nothing needed charging.

A plan can also be empty because the app is still waiting for something it plans with, such as the supplier's prices or the car's charge level, which is how it looks in the first minutes after setting up. In Short Term mode an empty plan means your Charge To level is already reached, and with smart charging Disabled there is no plan at all.

The finished plan is tidied

The raw result of the five steps can be untidy — fragments of charging scattered where each step happened to find its bargains — so before anything is shown or acted on:

• Touching blocks are merged into one continuous charge.
• A tiny fragment is slid along to join its neighbour where that costs nothing extra — how that move is chosen is covered in the help about how the cheapest slots are picked.
• A stray sliver of charging trapped alone between two trips is dropped when it is shorter than your Do not plan slots shorter than setting and nothing later depends on its charge — a two-minute plug-in between errands is more irritation than it is worth. If a later trip or your floor genuinely needs that sliver, it stays, however short.

Why the plan changes, and why it sometimes looks odd

• New prices rewrite it. If prices for the slots ahead have not been published yet, the app charges at the cheapest slots it knows about so far and revises as soon as newer prices arrive. A plan that changed overnight usually means better prices appeared.
• While the car is charging at home, the plan deliberately holds still. Recalculating mid-charge over every flicker of the battery reading would make the chart twitch under you, so the app waits until the block finishes — unless a price, a trip, or one of your settings genuinely changes, which takes effect at once. The hold lasts as long as that charge keeps flowing at home: unplugging, driving off, charging somewhere other than home, the charge stopping or finishing, and the power going off at the charger each end it, and the plan is rebuilt straight away from the charge the car actually has.
• Once a trip's departure time passes, its reservation is released. The charge for it was needed before departure; holding the reservation any longer would only block the slots after it from cheap charging. A chain of back-to-back trips is released as one.
• A trip beyond the published prices is planned for later. There is nothing to plan it against yet; it enters the plan when prices reach it.
• A trip that needs charging away from home ends the plan. If the app works out you cannot get home on what the battery will hold, it stops planning past that trip without making promises about a car it cannot reach.
• A charge target inside a trip is ignored, and you are told so by name — the trip is the real constraint, and charging you while driving is not something the app can do.

When it warns you it cannot make it

If, after everything above, a trip's departure still comes up short by more than about a percentage point, you get a Charge shortfall notification naming the trip, the shortfall, and how much charging time it represents — sent once per trip occurrence, not repeated as the plan rebuilds. It is only sent while acting could still help: when the battery is already set to be essentially full at the last departure you could charge for, more charging cannot exist, so the app stays quiet.

Stopping the charge yourself

If you stop charging at the car or in the carmaker's app while the app believes it should be charging, it takes that as an instruction and pauses itself rather than fighting you. In Long Term mode it stays paused until the end of the charging block it had planned, or an hour, whichever is later. In Short Term mode it stays paused until your Ready By time, and if that has already passed it does not pause at all. It resumes on its own afterwards — you do not need to switch anything back on.

Charge targets — how full, and by when

A charge target is a promise you ask the app to keep: "have the battery at least this full by this time". You give it a name, the days of the week it applies on, a time of day, and a charge level.

Recurring by design

A target is not a single dated appointment — it is a weekly pattern. "Weekday mornings, 80% by 07:30" is one target covering five days, not five targets. The app turns that pattern into the individual occurrences it needs to plan for, one per matching day.

You can have up to ten targets, and no two of them may come due on the same day at the same time — each moment a target activates is how the app tells them apart, so an edit that puts two of them on the same moment is refused when you save it, saying that two targets must not activate on the same day and time.

It only looks ahead as far as your Planning Horizon setting, so a target for next Thursday simply does not exist for planning purposes until the horizon reaches it. That is also why a target you just created may not appear to change anything yet, and why occurrences appear gradually as the days roll forward. Occurrences in the past are dropped as they pass.

Only you create targets

Every target is one you created yourself — the app never adds one on its own. Trips found in your calendar are a separate feature, planned for separately and in full. For each upcoming occurrence of a target you can say how sure you are it is really needed — that answer changes how much charge you actually get, and is explained in the charge-target confidence help.

What the app does with a target

Before each occurrence, the app checks what charge the battery is predicted to have at that moment and, if it falls short, schedules charging beforehand to close the gap. It looks for the cheapest slots available, so a target set for 07:30 is typically met by charging in the small hours, not at 07:00.

Two things stop a target being planned for:

• A trip is happening at that moment. The trip wins, the target is skipped, and you are told which target was ignored and which trip clashed with it — the app cannot charge a car you are driving.
• The target lies beyond what the app can see — past the published prices, or past a trip the app has worked out you cannot get home from. In that case it is not dropped, just deferred; it is planned for once the horizon catches up.

Targets and your everyday limits

A target overrides your Keep charge lower than setting for as long as it takes to meet the promise — that is what makes it a target and not a preference. Once it has passed, the app returns to your everyday limits and will let the charge drift back down to them.

Deleting a target takes effect immediately, including any occurrence already planned for tonight.

If the app cannot read the targets you have saved, the editor shows Unavailable in place of the list and saves nothing, so your targets stay exactly as they were; updating the app to its latest version usually fixes it.

Confirming whether you really need a charge target

Every charge target is one you created yourself, and for each of its upcoming occurrences the app lets you say how sure you are that you actually need that one — the Needed? prompt shown beside the target. Guessing wrong in either direction costs you something: too cautious and you pay for charge you did not need, too relaxed and you set off short.

The four answers

• Yes — plan for the full target.
• Most likely — the answer used until you say otherwise.
• Likely
• No — do not plan for it at all.

What your answer actually does

Your answer does not switch the target on or off; it scales it. The app multiplies the target charge level by a weight for the answer you gave, and plans for the result. Yes weighs 1, so a target of 80% stays 80%. No weighs nothing, so the target contributes nothing to the plan. The two middle answers sit between, at three-quarters and one-half unless you have changed them.

So "most likely" on an 80% target asks the app to plan for 60%, and "likely" for 40%. That is the point: a target you are not sure about still gets you part of the way there, at a cost that matches how likely it is, instead of forcing an all-or-nothing choice.

Tuning the middle two

The two middle weights are yours to change, and only those two — Yes and No are fixed at everything and nothing. The one rule is that they must stay in order and stay between the extremes: "likely" below "most likely", and both strictly between nothing and everything. Setting them closer to 1 makes the app more cautious about uncertain targets and you will charge more; setting them closer to 0 does the opposite.

Why you are asked again

A target that repeats — a weekly commute, say — is asked about each time it comes round, because your confidence genuinely differs week to week. Answering is never required; leaving it alone keeps "most likely".

Your answers are stored, and only for the occurrences currently in the plan: once an occurrence passes — or disappears because you edited the target — its answer is discarded. An answer applies to the one occurrence you gave it for, never to the whole repeating target.

Reading the charging chart

The charging chart, on the Timeline tab, is the plan drawn out: what the app intends to do with your car and what it expects your battery to look like while it does it. Until the first prices or events arrive it shows a grey placeholder with Loading charging data… beneath it — normal while setup is still completing; until your car and energy supplier are connected it says so instead, with a Go to Settings link. If the prices or events arrive in a form the app cannot read, and there is nothing else to draw, it shows Unavailable until readable ones arrive.

The predicted battery line

The line is built by walking the plan forward from the battery's current level. Each planned charge raises it at your measured charging speed; each journey lowers it by that trip's predicted usage; between events it stays level. A long trip can predict more usage than the battery holds, and the line then shows zero. The line is a prediction, and it redraws whenever its ingredients change: new prices, a moved calendar entry, a fresh battery reading.

The events on it

• Journeys — start and end markers, named after the calendar entry they came from, and carrying how that trip's usage was estimated: via history - from your own similar past drives, via route - from a typical route distance multiplied by your average consumption, or parked for a leg of a chain of trips whose next appointment is in the same place, so the car sits where it is and only loses the trickle a parked car loses.
• Planned charges — start and end markers, the start labelled with the block's average electricity price and its estimated cost, computed from your car's measured charging power.
• Charge targets stand as vertical bars at their deadline: solid colour up to the level the planner actually aims for — the target scaled by how sure you said you were — fading above that to the full target level. A bar whose occurrence falls inside a journey is drawn as a single faded grey bar, because the planner ignores a charge target that clashes with a journey.

The price band

The prices shown run from the current slot forward, rolling on as each slot ends, and each is flagged as published or predicted — where the predictions come from is covered in the help about prices, and the chart is honest about which is which. A repriced slot is why a plan can shift under you: the prediction changed or was replaced by the real number.

Working the chart

• Drag sideways to move through time; pinch to zoom in or out; double-tap to snap back to the full range.
• The expand button in the chart's top corner turns the chart sideways and gives it the whole screen; while you are there it becomes a shrink button that brings you back, and the chart stays upright afterwards until you leave the tab and return. Rotating the phone does the same while you are on the Timeline tab, and rotating it upright is the way back from that; other screens stay upright either way.
• The refresh arrow beside it brings the chart up to date there and then, for when you would rather not wait for the next update.
• Touch and hold, then slide to run a scrubber line across the chart. Balloons follow your finger showing the electricity price at that moment — marked Actual or Predicted — and, where the line crosses one, the journey or charge under it with its battery change, or a charge target's level and confidence.
• Tap a journey, charge or charge target to pin its balloon. It stays put until you drag, pinch or tap elsewhere, and it closes as soon as the plan changes — a balloon describes the plan as it stood when you tapped it, so a balloon vanishing on its own means the plan moved underneath it and you can tap again to read the new one. A journey's balloon is headed by its calendar entry's name, with the battery change and how the usage was estimated beneath it — 50% → 40% · via route. A charge's is headed by what it adds, its price and its cost, with the battery change and why the app booked it beneath — 50% → 70% · trip, yummy, using the same words as the Schedule table on the home screen's Energy card and explained in the smart-charging help. A charge target's is headed by its name, marked (Inactive) for an occurrence the planner is ignoring because it falls inside a journey.

The lines across it

In Long Term mode, dashed horizontal lines mark your configured levels, each labelled at its right edge: min — your Keep charge higher than setting, max — your Keep charge lower than setting, and super-yummy max — the higher ceiling reserved for very cheap electricity, explained in the smart-charging help. When there are no journeys or charges to trace a battery line through, a flat line still shows the current charge level.

Where the electricity prices come from

Smart charging is built on knowing what each slot of electricity costs — the half-hour periods your tariff prices separately — and those prices come through your supplier connection.

The tariff has to publish half-hourly prices

Only a tariff that publishes a price for every slot — Octopus's Agile family — gives the app something to plan with. If your account's active tariff is not one of those, the app tells you once, when it notices, that prices cannot be retrieved on that tariff; smart charging then has nothing to optimise against. The reminder does not repeat every day — it fires again only if the situation resolves and then reoccurs.

How far ahead prices reach

Octopus publish the next day's prices in the late afternoon — usually just after four o'clock, sometimes a few hours later. The app starts asking at four and keeps asking every few minutes through the evening, so new prices reach your plan within minutes of being published; if they still have not arrived by eleven it carries on asking through the night, just less often. For the slots beyond what has been published, the app fills in predicted prices from a regional forecast and plans across the whole stretch — so a plan always exists; it firms up when the real prices land. The chart marks which prices are published and which are predicted, and the app only looks as far ahead as its planning window in any case.

A temporary failure to fetch prices does not wipe the prices already held: the app keeps the last successfully retrieved set and carries on planning with it, so a supplier hiccup does not dismantle tonight's plan.

The warning that matters

One situation deserves a notification, and gets one: your car is plugged in at home with a ready-by deadline, the prices the app holds run out before that deadline, and the next expected price publication will come too late to fill the gap. The app then tells you it cannot plan charging up to your deadline because prices only reach so far. If new prices are due in time, no warning — the plan simply completes itself when they arrive. And while the app is still asking for that evening's batch, it waits for the answer before deciding whether to warn you; prices that run out before tonight is even over are the one case it acts on at once, because that batch starts where tonight ends.

How the cheapest slots are picked

When the app has decided how much charge is needed by when, one job remains: choosing exactly which slots to run the charger in. This is where those choices come from.

The basic pick

The app knows how fast your car charges (measured from your own history), so a needed amount of charge converts into a needed amount of charging time. The window between now and the deadline is divided into the supplier's slots — the half-hour periods your tariff prices separately — any time you have driving planned via calendar events is removed, and the slots are taken cheapest first until the needed time is covered.

Refinements on top of that:

• Ties break in your favour. The needed time usually ends part-way through a band of equally-priced slots, and which of those to take is a real choice — so the app weighs them and picks by three rules in order: cheapest overall, then the fewest separate blocks, then the earliest start. Fewer blocks because starting and stopping a charge repeatedly is pointless wear; earlier because a plan that finishes sooner survives surprises better.
• The excess is trimmed from the dearest edge. The cheap slots usually cover slightly more time than needed, so the surplus is peeled off the most expensive selected time, cut in the way that lets charging start earlier.
• No stand-alone short bursts. A minimum length applies to any isolated charging block (a setting). A short leftover fragment is not simply kept: it is moved into the cheapest unused slot next to the rest of the plan — never into a journey — and a boundary scrap too short to stand alone is dropped when the remaining slots still cover the need.
• A short block is slid to join its neighbour when the move is free. After the whole plan is assembled, a block shorter than one slot that sits inside a stretch of identically-priced time is slid along that stretch until it touches the next block, and the two merge into one continuous charge. The move never changes what the charging costs — it only happens within equal prices — and it keeps clear of your driving: a block never lands on a trip and never crosses one, so it stays in the same gap between trips it was planned for. A fragment whose nearest block sits beyond a trip stays where it is, as does one with no free equally-priced path to a neighbour.

When there is not enough cheap time

If the slots between now and the deadline cannot fit all the needed charging — the price outlook (published and predicted alike) runs out, or the deadline is simply too close — the app does not give up or fail: it uses everything available and delivers as much charge as fits. The plan then improves itself when the next day's prices arrive.

What each block claims to cost

Every planned block carries an estimated price and cost, computed from the block's actual electricity prices and your car's measured charging power — the same figures the chart shows against each planned charge. They are estimates of a plan, not meter readings; the savings view is where real costs live.

How the plan becomes actual charging

A plan is just a list of time blocks. This is how it becomes a car that actually charges — and, equally important, how the app avoids acting when it is not sure.

Should the car be charging right now?

At any moment there is one active schedule (the long-term plan, or the simpler Short Term plan). Inside one of its blocks the car should be charging; outside them it should not. And when there is no computed schedule yet — the app is still waiting for prices, the battery level, or the measured charge speed — the answer is deliberately unknown, not "no": on that answer the app leaves an already-running charge alone. A charge that starts a few minutes before its planned block is treated as on schedule, not fought.

Inside a block the app charges until the battery reaches the level that block was planned to reach, and stops there — a little before the block's own end when the car charged faster than expected. A car stopping of its own accord does not end the charge: cars stop the moment they reach the charge limit set in them, and that limit may be one left over from an earlier session, well below what the current block is aiming for. Such a car has its limit raised and its charge restarted, so a car that stops early still gets where the plan needs it.

In Short Term mode one extra rule applies: if the plan's last block has ended but the car is still charging — real charging ran slower than the measured speed assumed — the app lets it keep going instead of cutting the charge short of your target.

Starting a charge, in the right order

When charging is due and the car is plugged in at home:

1. An asleep car is woken first. Separately, a car whose battery level has been unknown for a long while is also woken, so plans are not built on stale information.
2. The car's own charge limit is set before anything starts. The limit is set to just past the level the current block plans to reach (in Short Term, to your chosen level), and never below 50% — the lowest limit cars accept. The start command is sent only after the car confirms the limit: a car whose limit sits at or below its current battery level responds to a bare "start" unpredictably, so the order is strict.
3. Then the charge is started, and verified against the car's own reporting as every command is. Some cars begin charging by themselves as soon as the limit is raised above the battery level; a car that waits to be told is started by the app, so either way it gets going.

Stopping — with restraint

A charging car that should not be charging is asked to stop, but only under conditions that make a mistake unlikely: the app must know the car is at home, and a stop decision reached within the first moments after the app starts up is held for a short settling period (about fifteen seconds) before acting — at startup the plan's ingredients arrive one by one, and an early half-built schedule can briefly claim a legitimately-charging car should stop.

And one start is never sent: if charging stops and the app did not stop it, that is read as you stopping it — at the car or in the maker's app — and the app pauses itself instead of restarting the charge. The pause behaviour is covered in the smart-charging help.

How the app learns your charging speed

Every plan depends on knowing how fast your car charges: it is what turns "add 30%" into "needs about three hours". Rather than asking you, the app measures it from your own charging history — so it tracks reality when a charger is changed, the weather turns cold, or the battery ages.

How the measurement works

Every six hours the app re-measures two figures from your recent at-home charging:

• Charge speed — battery percent gained per minute of charging.
• Charge power — the average rate energy was drawn from the grid, used for the cost estimates shown against planned charges.

It looks back over up to the last thirty days, keeps only at-home sessions of at least half an hour (shorter ones are dominated by start-up noise and prove nothing), and takes the most recent sessions first until it has gathered twelve hours of actual charging, or all there is when there is less. Each figure is a simple average over the sessions that carried it, and counts as measured once those sessions add up to at least an hour. Unplugging splits a charge into separate sessions, so a long charge interrupted by a trip counts as its pieces, each of which needs half an hour to count at all.

Before there is history

A new setup has no sessions to measure, so the app starts from typical home-charging values — a standard 7-kW-class home charger, about 7.8 kW — and the expanded Energy card shows each figure greyed with (calibrating) while it is still that starting value. Plans use the starting values too, so on a slower charger such as a 3-pin "granny" charger a planned charge can fall short of its target until the real speed has been measured.

Whenever a charge at home finishes while a figure is still calibrating, the app re-measures shortly afterwards rather than waiting for its next six-hourly check, so the real figures replace the starting ones soon after your first charge of an hour or more. Until the very first measurement completes, planning waits.

There is nothing to configure here, and that is deliberate: a number you typed once would silently go wrong the day anything changed, whereas the measurement corrects itself.

Charge now — charging on demand

Charge now starts a charge immediately, up to a level you choose, regardless of what the smart plan thinks of the prices. It exists for the day you need the car charged now.

When the request is refused straight away

The app refuses, and tells you the reason, when:

• The car connection is not running. The app has no live link to your car — usually because the connection is still being set up, or has stopped working.
• Smart charging is off. Off means the car is under your direct control and the app does not command it at all; use the car or its maker's app.
• The car is not plugged in at home.
• The charger has no power.
• The battery is already at or above the level you asked for.

The level itself must be between 50% — the lowest limit cars accept — and 100%.

What an accepted request does

1. An asleep car is woken.
2. Smart charging is paused for the estimated length of the charge (based on your measured charging speed, with a generous margin, and at least an hour), so the smart plan cannot stop the very charge you asked for. If a longer pause is already running, it is left in place.
3. The car's own charge limit is set to your chosen level, and the app waits for the car to confirm it.
4. The charge is started.

If it cannot start in time

An accepted charge gets about fifteen minutes to become startable. If the car never wakes, or mid-way the situation turns invalid — the car is unplugged, the charger loses power — the request is abandoned and you get a notification saying why. The pause the request created is lifted when that happens, so an abandoned Charge now does not leave smart charging silently suppressed.

Resume smart charging is the companion command: it ends a pause on request, and does nothing if smart charging is not paused. It also cancels a Charge now that has not started yet — the pause that charge was waiting behind is the thing you just lifted.

What the app can see about your car

While your car is awake and connected, it streams readings to the app: battery level, whether a cable is plugged in, whether it is charging, the charge limit set in the car itself, its location, speed and gear, cabin temperature (both measured and the temperature you asked for), and two running energy counts for the current plug-in — the energy drawn from the grid, and the energy that actually reached the battery. The two differ by the losses charging always has, and both are kept; your savings are worked out from the grid-side count, which is the one your bill is for. It also watches the odometer, which is how it knows how far each of your drives went; what it does with that is covered in the help on learning your car's energy use.

The car's overall state

Everything the app shows and decides starts from one of four states:

• Unreachable — the car is asleep or out of coverage and sending nothing.
• Charging.
• Not charging — awake, but no charge running. A car that stopped because it reached the charge limit set in it counts as not charging too, however it words that itself: the app works out whether more charge is due from its own plan, so a car that stops early at a limit left over from a previous charge is simply started again.
• No power — plugged in to a charger that is not supplying power.

When readings go stale

A quiet car sends nothing, so every reading has an age. For readings where the last known value is more useful than a blank — the battery level, the energy counts, the odometer — the app deliberately keeps the last known value when the car goes quiet, instead of showing nothing: a parked, sleeping car still has the battery and the mileage it last reported. Readings that only make sense fresh are treated as unknown until the car speaks again.

At home, or not

The car counts as at home when its reported position falls within a small area around your saved home location — about fifty metres each way. Two things make this undecidable, and the app then treats "at home" as unknown: no saved home location, and no usable position report from the car.

Driving, or parked

The car counts as driving when it is in a driving gear with the motors powered and moving faster than walking pace; it counts as stopped when the motors are off or it is in park. Anything in between — or a car sending nothing — is unknown, and decisions that need to know wait.

How the app asks your car to do things

The app sends your car five kinds of request: wake up, start charging, stop charging, set the charge limit, and turn the climate on or off. The climate one is deliberately the most cautious of the five, and is covered in the preconditioning help; how the app treats the rest explains most of what can look odd about a charging session in progress.

"Accepted" is not "done"

Car makers' servers will happily accept a command and then fail to carry it out — a stop request can be acknowledged while the car, mid-conversation with its own cloud, keeps charging. So the app never trusts the acknowledgement. A command counts as done only when the car's own reporting shows the effect: charging actually started, actually stopped, or the car now reports the new limit. Until then the request stays open.

If the effect has not appeared after about ten minutes, the command is sent again, up to three times; only then does the app treat it as failed and raise the problem. This is also why the app waits until it can see the car's state at all before sending anything — a command fired blind could never be verified.

Waking a sleeping car is different

A car that will not wake is common (deep sleep, poor signal, a parking garage) and usually fixes itself, so wake-up requests are patient, not insistent: retries are spaced further and further apart — starting around an hour, stretching to about a day between attempts — and continue for up to two weeks. If the car still cannot be woken, you get a notification saying so. Any successful contact with the car resets this patience for next time.

What cancels a pending command

• Switching smart charging off abandons every pending charging request. Off means off: nothing fires minutes later from a stale retry.
• Pausing smart charging is more selective, because a pause is how a manual charge is protected: requests a manual charge relies on — waking the car, setting the limit, starting the charge — stay alive through the pause, while any pending stop request is abandoned, so the pause cannot strangle the very charge it exists to allow. When smart charging resumes, a car found charging outside its schedule is asked to stop afresh.

The drives the app remembers

When the app sees your car go from parked to driving and back to parked, it records that as one drive: when it started and ended, where it started and ended, the battery level at each end, and how far the car travelled, taken from the difference in its odometer over the drive. Nothing in between is kept — no route, no speeds, just the two ends of the drive and its length. A car that does not report its mileage still has its drives recorded, without the distance.

Two kinds of drive are deliberately not recorded:

• Round trips that end where they began — back within about a hundred metres of the start. A loop says nothing useful about how much battery a journey to a place costs, which is the only reason drives are kept at all.
• Drives with a missing ingredient — if the car never reported a usable position or battery level for the drive, there is nothing honest to record, so nothing is.

What they are for

Predicting future trips. When a calendar entry points somewhere you have driven before — matched at both ends of the drive, to within a few hundred metres — the app prefers what that drive actually took, in time and in battery, over any estimate. More recorded drives mean better predictions.

They are also what the app measures your car's energy use from: how much battery a mile costs, and how much the car loses standing still between drives. That measurement is covered in the energy-use help.

How long they are kept

Twelve months, then deleted — deliberately shorter than the five years the charging history is kept, because these records carry locations and nothing needs a drive older than a year. Deleting your account removes them with everything else.

How the app learns your car's energy use

Planning a trip needs two numbers about your car: how much battery a mile of driving costs, and how much battery it quietly loses while parked. The app measures both from your own driving, so they follow the car as tyres, season, driving style and battery age change.

Both are shown on the expanded Energy card, as Consumption in percent per mile and Vampire drain over 3h in percent.

Why standing loss is quoted over three hours

A parked car does not lose charge at a steady rate. Settling down after a drive costs it something whatever happens next, and on a Tesla sentry mode runs for a while before the car finally sleeps — so a short stop costs far more per hour than a long one. Measured over one car's own parking across five months, stops of one to four hours lost about seven and a half percent a day while stops of ten to twenty-four hours lost about two.

So the app measures two things about your car: what a stop costs simply by happening, and what it then loses for each further hour. The card shows the two put together over three hours, which is about as long as a trip in your calendar keeps the car waiting, and planning uses the pair to work out each wait from its own length.

How the measurement works

Every six hours the app re-reads your drives from the past few months and works all of it out again.

• Consumption comes from your longer drives — from about ten miles up. It adds up the distance of the most recent of them and the battery each one used, most recent first, until it has around thirty miles to work from, then divides one by the other. Short hops are left out because warming or cooling the cabin costs much the same whatever the distance, so on a short drive that dominates the answer.
• Standing loss comes from the gaps between drives — the car sitting still for an hour or more, away from home. Every such gap in the past few months counts, and the app fits the two figures above to the whole set at once, so the answer follows the seasons and your car's age. Parking at home is left out: on a Tesla, sentry mode is typically set to run everywhere but home, so the car loses charge faster away — and it is the loss while you are out that a journey has to allow for. Any gap in which the car was plugged in is skipped too, because a plugged-in car can hold its charge from the wall.

Drives and gaps where the battery reading rose are left out of both: something charged the car, and including them would flatter the figure. A gap losing far more than any parked car could is left out for the same reason: something was drawing on the battery, usually a drive the app did not record, such as a round trip that ended where it began, or the car warming or cooling its cabin. Counting it would overstate what the car loses simply sitting there.

Before there is enough history

A new car, or one that has not driven far lately, will not have enough to measure from. Standing loss needs at least ten gaps to work from, and they have to differ in length — a car that always stops for about the same time shows what a stop costs but not how that divides between settling down and standing still. Until there is enough, each figure shows a starting value with (calibrating) beside it, greyed to mark it as provisional — about four tenths of a percent of battery per mile, and seven percent a day standing, which works out at just under one percent over three hours. Planning uses those same starting values in the meantime, so trips are still planned from the first day; they simply get more accurate once your own driving replaces them.

The two figures are measured independently, so it is normal to see one calibrating while the other is already measured — long drives and varied stops accumulate at different rates.

What they are used for

Both feed the battery a calendar trip is expected to need: the distance times your consumption, plus the loss while the car is parked at the other end. That total is what the app adds to your Keep charge higher than setting when deciding how full the battery must be before you set off.

Where you have driven the trip before, the app uses what those drives actually took in place of the consumption figure — standing loss is still allowed for on a chain of trips, where the car waits between them. How that matching works is covered in the drive-history help.

Setting your home location, and what depends on it

Your home location is the place the app treats as "home" — where your charger is, and where trips start and end. You set it once, on the settings screen.

Why it matters more than it looks

Almost everything the app does is gated on knowing where home is:

• Charging. The app only manages charging when the car is plugged in at home. Plugged in somewhere else, it leaves the car alone entirely — it has no business scheduling someone else's electricity, and your prices do not apply there.
• Preconditioning. Warming or cooling before a trip only happens at home.
• Trip planning. The drive to each calendar entry is worked out from home, so the departure times and the charge you need for a trip both depend on it.

If it is not set, or is set to the wrong place, the symptom is usually silence: the car never charges on schedule, and nothing is preconditioned, because as far as the app can tell the car is never home.

How close counts as home

The car is considered at home when it is within about fifty metres of the location you set — a square roughly a hundred metres across, centred on it. That is tight enough not to catch a neighbouring street and loose enough to cope with ordinary satellite-position wobble and where on the drive you happen to park.

If your car reports its position only occasionally, the app keeps using the last position it was given.

Getting it right

Set it to where the car actually parks and charges, not to the middle of your building or the postcode centre — fifty metres is not much, and a pin dropped on the wrong side of a large property can leave the car permanently "not at home".

If charging or preconditioning is not happening and you cannot see why, this is the first thing worth checking.

Warming or cooling the car before you leave

Preconditioning brings the cabin to a comfortable temperature before you set off, and warms the battery so the car drives and charges at its best in cold weather. It runs off the trips the app knows about, so it only happens when the app expects you to leave.

When it will run

All of these have to be true:

• The car is at home. Away from home the app does not manage climate at all.
• There is a trip in the calendar and it starts within the next three hours. Trips further ahead are ignored until they come closer.
• The cabin is far enough from comfortable. The app compares the temperature against your target and only bothers if the gap is at least your Temperature difference to trigger climate setting. On a mild day it will do nothing, which is deliberate — running the climate to change the cabin by two degrees spends energy for something you would not notice.

For the comparison it prefers an actual cabin reading from the car, but only while that reading is recent — within about three quarters of an hour. A parked car in sunshine heats quickly, so an older reading is worse than useless; when there is no fresh one it falls back to the outdoor forecast for the hour you are leaving. If neither is available it does not precondition, and picks up again by itself once a reading or forecast returns.

If you have not set a target cabin temperature in the car, the app aims for 20°C.

When it starts

Not at a fixed lead time — the app estimates how long your car takes to get from the current temperature to the target, and starts that long before your departure. It learns this from what actually happened on previous runs, so the estimate improves with use and differs between a mild morning and a freezing one.

Before it has estimated the lead time for a particular temperature gap, it allows about a minute for each degree between the cabin and your target — a car baking at 39°C with a 21°C target gets roughly eighteen minutes, a mild day gets a couple. Once the app has timed any run at all it uses your car's own measured pace for gaps it has not met yet, and once it has timed that particular gap it uses the real figure. However it arrives at the figure, it always sits between two minutes and half an hour.

Only clean runs teach it: a timing starts when the climate had been off for at least half an hour beforehand (so the cabin had settled to its real starting temperature) and the car was standing still, and it is kept if the target is reached within half an hour. The timing carries on once you drive away, so the ordinary case — setting off before the cabin is quite there — still teaches the app how long that warm-up really takes. Runs cut short by the climate going off, runs that change target midway, and runs that drag on past half an hour are discarded. The outdoor forecast used as the fallback is for your home location, refreshed daily.

Once a run has started, the app freezes the temperature it began from and keeps using it. That is why the run does not cancel itself halfway: as the cabin warms towards the target the gap shrinks below your threshold, and without that freeze the app would stop the very thing that was working. Changing your target temperature or threshold still takes effect for runs that have not started yet.

If the climate is already running

If the climate is on when a run is due to begin — because you started it from inside the car or from the maker's app — the app steps back and leaves that trip's climate to you. For as long as that trip is the one it is watching, it sends no climate command of its own, so switching the climate off leaves it off. The app takes over again at your next trip.

When it stops

At your departure time the app keeps the climate on for a grace period — your Stop climate if no journey taken for setting — in case you are running late. If you have not gone by the end of it, the app concludes you are not going, switches the climate off, and treats the trip as missed. That is the setting to raise if the car keeps cooling down in cold weather or warming up in hot weather before you actually get in.

The command itself is deliberately timid

Turning the climate on or off is the app's most cautious command: where other commands get a few attempts before the app gives up, a climate command is retried only once. An over-insistent retry risks leaving the heating running on a car the app can no longer see — so if the car does not confirm, the app lets it go. A car that fell asleep right after the command is assumed to have received it.

Why it did not run

The Climate card on the home screen carries a line under its readings saying what the app is doing about the cabin right now, so the reason is already on your screen. It says one of:

• Preconditioning for your trip — a run is under way.
• Will precondition before your trip — a trip is close enough to manage and the app is waiting for the moment it worked out above.
• Cabin already close to your target — the gap is smaller than your Temperature difference to trigger climate setting. Lower that setting if you want the app to bother on milder days.
• You are running the climate — the climate was already on when the run was due, so the app left that trip's cabin to you and will send no command of its own until your next trip.
• No trip coming up — nothing in the calendar the app recognises as a car trip. The calendar help covers what makes an entry one.
• Next trip is too far ahead — there is a trip, and it is more than three hours away. The line changes by itself as it comes closer.
• Next trip is marked /noc — every trip ahead carries the tag that says do not precondition for this one.
• Car is away from home — away from home the app manages no climate at all.
• No temperature to work from — no recent cabin reading and no forecast covering your departure hour, so there is nothing to compare against your target. It picks up by itself when either returns.
• Waiting for information it needs — something the decision rests on has yet to arrive: where the car is, what your calendar holds, or the weather forecast. It settles by itself in the ordinary case; if it stays there, check that your home location is set, since the forecast is fetched for that place and without it there is nothing to work from.

Expanding the card shows the same line beside every past reading, which is how to find out what the app was doing at the time, not now.

What the savings figures mean

The savings view answers one question: was being on your tariff, charging the way the app charges, better than the alternative? It compares, day by day, what your electricity actually cost against what the same electricity would have cost on a reference tariff — currently Intelligent Octopus Go, the only reference tariff supported.

How the comparison is built

For each day the app takes the energy you actually used and prices it twice — once at the rates you were really on, once at the reference tariff's rates. The difference between the two totals is the day's saving. Because the same energy is priced both ways, the comparison is about tariffs and timing, not about using less.

Where it can, it splits the day between house and car, so you can see what the car contributed. The standing charge is always shown on its own and never folded into a per-unit figure — it is a fixed daily fee, and spreading it across the units you happened to use would make a light day look expensive.

The three average prices

Under the costs the table shows three unit rates, each one under Yours beside what it would have been on the Reference tariff: House average, Car average and Combined average. Each is that side's cost divided by that side's energy — house cost over house energy, car cost over car energy — so each is an average price per unit, weighted by how much energy went through at each rate. All three cover energy only; the standing charge keeps its own line.

The house and car figures do not overlap. The car's energy is taken out of the meter reading first and the house figure is what remains, so no unit of electricity is counted in both and neither figure contains the other. Combined average puts the two back together — all the energy cost divided by all the energy — which makes it a blend of the other two: it lands between them, nearer whichever of the two used more energy, and it is never the two added together. Heavy overnight charging pulls it down towards the car figure; a spell of little driving leaves it close to the house one.

The figures cover the whole period you have chosen, and the division is done on that period's totals, not day by day, so a heavy day weighs more in the average than a quiet one. Each day's own combined rate is in the daily breakdown.

Why some figures show a dash

A dash means not known, which is deliberately different from zero. There are two reasons for one.

• The house-and-car split is not available for older days. Before the app started recording your car's charging, there is no way to tell which part of the meter reading was the car. That day's totals, standing charge, combined average and saving are all still correct — only the split into house and car is unknown. One such day in the period you have chosen blanks the house and car energies and costs, and all three average rates, for the period as a whole; the totals and the saving still cover every day of it, and a line under the table says which day the breakdown is available from.
• The cost on your actual tariff cannot be worked out. Suppliers stop publishing rates for some old tariffs. When that happens the energy you used is still known but its price is not, so the actual-cost figures and the saving are blank for that day. The reference side stays populated. Such days are left out of the period's figures on both sides, so the comparison stays like for like, and a line under the table says which day it covers from.

In both cases showing a zero would be a lie, so nothing is shown. A figure the app cannot read at all shows Unavailable in place of the dash and is treated like a missing one: an unreadable total or standing charge leaves its day out of the period's figures on both sides, and an unreadable house or car figure blanks the split for the period, as an older day does.

The savings screen

The full comparison lives on the Analytics tab, headed Energy savings. A row of period chips — 24h, 7d, 30d, MTD (this month so far), 3m, 6m, 1y — picks the span, and Custom… opens a start-and-end date form for any other range, where each date is either typed or chosen from the calendar button beside it. On an iPhone the calendar stays open while you move between months and years and closes when you tap the tick beneath it; on an Android phone it closes on the day you pick. The screen reopens on whichever period you last looked at. Below the chips sit the period's three headline figures — You paid, Reference, and Saved (or Extra cost, in red, when the reference tariff won) — then the full cost table: the energy used by house and car, and each cost on your tariff beside what it would have been on the reference — house cost, car cost, standing charge, the totals, and the three average unit rates. Show daily breakdown opens the same figures day by day, newest first, in a side-scrolling table with a column for each of them — House p/kWh, Car p/kWh and Avg p/kWh among them, and the reference's beside them — and Export CSV shares those daily rows as a spreadsheet file. A period from before your data begins says No energy data for the selected period. If the figures are slow in coming, the card says so after a couple of minutes — "Your savings are taking longer than usual to work out. The app is still trying." — and it keeps asking, so they appear by themselves once they arrive. The refresh arrow in the card's corner fetches the figures again, and so does pulling down on the daily breakdown.

A rolling period always ends on the most recent complete day the comparison has been worked out for — today is never included, because its day is not finished. Why the newest days can lag slightly further behind is covered in the savings data-freshness help.

The range on the home screen

The home screen's Energy savings card shows a chosen span of recent days, and your Savings period for home screen setting is which span it shows. Unless you change it, that is the last 30 days; the spans on offer run from the last 24 hours up to a full year, including month-to-date. It only changes the home card — the full history stays available on the Analytics tab.

Reading it fairly

A negative saving on a single day is normal and not a fault: on a day you had to charge at short notice, or one where prices barely moved, the reference tariff can genuinely win. The figure worth judging is the running total across a period long enough to include both cheap nights and awkward ones.

How one day's comparison is assembled

Each day on the savings chart is built from three ingredients: your meter readings, the tariff you were actually on, and your car's at-home charging sessions.

Your side of the comparison

• Meter readings. Half-hourly readings from every electricity meter on your account are added together. Only consumption meters count — an export meter (solar, for instance) measures what you sell, not what you buy, and is left out.
• Your rate. Each slot is priced at the rate of the tariff you were actually on at that moment. If you switched tariff part-way through a day, both tariffs price their own slots correctly; the day is labelled with whichever tariff covered more of it.
• The car's share. Each at-home charging session's energy is spread evenly across the slots it ran. A session crossing midnight contributes to both days, and if you have more than one car, all of them count. Within any slot the car's share is capped at what the meter actually recorded — the meter is the truth — and everything above the car's share is the house. Sessions away from home are not counted at all: public charging is not bought on your home tariff, so it has no place in a home-tariff comparison.

The reference side

The same day is then priced as if you had been on the reference tariff — Intelligent Octopus Go, the only reference tariff currently supported — using that tariff's prices as published for that day: the day's lowest published rate is taken as its cheap overnight price and the highest as its standard price, so a price change part-way through your chart affects only the days after it, and one odd slot's reading cannot distort a whole period. How the charging is re-timed onto that tariff is described separately.

Days that are missing entirely

A day is left off the chart when:

• No meter reading exists for it at all. Typically days before your current meter was fitted — a meter exchange leaves no readable history on the old one.
• No qualifying reference tariff was published for your region that day, so there is nothing honest to compare against.

Two further conditions blank out parts of a day instead of the whole of it — a past tariff whose prices are no longer published, and days from before your car's charging began being recorded. Those show dashes, and are explained with the rest of the figures.

How past charging sessions are pieced together

The savings comparison needs to know when your car charged and how much energy it took. Cars do not hand over a tidy statement of that — the car reports energy consumed during charging and charge start and end events, and the app uses that to record charging sessions.

Where a session starts and ends

A charging session begins with the first report showing the car charging, and ends with the first report clearly showing it stopped — no longer charging, whether because it finished or because it was stopped, or no power.

Cars go quiet: they sleep, lose signal, or report nothing for a while. A silence, or a stretch of the car being unreachable, does not end a session — a brief drop-out mid-charge keeps the session whole. But there is a limit of two hours: if that long passes with no fresh evidence of charging, the session is treated as over at the last moment charging was actually seen. Without that limit, a car unplugged and driven away without ever reporting a clean stop would appear to have "charged" across days of idleness.

A session that never gets a clear end at all — the records simply stop — is left out entirely. Its real end and energy are unknown, and guessing would count idle time as charging.

How the energy is counted

The car carries a running meter of energy delivered since it was plugged in. That meter resets when the car is unplugged — not when charging merely pauses, as it does under smart charging. The app therefore counts only the rises in that meter during the session, plus a fifteen-minute grace after it, because the final reading often arrives slightly late. Counting rises only means:

• a smart-charging pause and resume within one plug-in is never double-counted;
• the reset on unplugging is ignored;
• energy delivered during a quiet gap the car never reported as charging is left unattributed.

If no meter reading at all lands within a session's window, its energy is recorded as unknown — deliberately not zero, because "not measured" and "nothing was delivered" are different facts.

The car keeps two such meters and the app records both: the energy drawn from the grid, which is what your supplier bills you for and what a meter at your house would show, and the energy that actually reached the battery, which is smaller by the losses charging always has. Your savings are worked out from the grid-side count, because that is the energy you paid for.

Battery percentage gained

A session's battery gain is the difference between the first and last battery readings seen during it. If either reading is missing, or the change is not positive — indistinguishable from reading noise — the gain is recorded as unknown.

At home or not

Whether a session counts as at home is fixed by where the car was when the session began, so a momentary location wobble mid-charge does not split or reclassify it.

The tariff your costs are compared against

The savings comparison prices every day against Intelligent Octopus Go — Octopus Energy's smart-charging EV tariff, with a cheap overnight rate for a car it is allowed to schedule. It is the natural "what if" for anyone charging an electric car at home, which is why it is the yardstick.

One realistic journey, not a daily best-buy

Octopus sells the fixed-price version of this tariff in dated editions: each edition is open to new sign-ups for only around a month before a newer one replaces it, but a household that signs onto one keeps its prices for a full twelve months. Re-picking "whatever is on sale today" for every day of your chart would hop between editions monthly — something no real customer experiences.

So the comparison follows the journey a real household would take:

• Before the twelve-month fixed editions existed — they appeared in mid-2025 — each month is priced on the ordinary variable version of the tariff.
• From the first fixed edition onwards, the comparison signs onto it, rides it for the full twelve months, then re-signs onto the newest fixed edition available at that point — one re-fix a year, indefinitely. (The fixed and variable versions share the same cheap overnight rate, so this choice is about realism, not about flattering either side.)

The choice for a given calendar day is anchored to the tariff's own history, never to the span of your chart: a day resolves to the same tariff whether you are looking at a week or at five years, so the figures for a day never shift just because you widened the period.

Tariffs deliberately left out

Several Octopus tariffs share the branding but would make a misleading yardstick, so they are never chosen:

• The EV Saver version. A separate tariff whose overnight rate differs from — and at times dips well below — the standard one. Pricing against it would answer a different question from "what would the ordinary smart EV tariff have cost me".
• Short-lived sign-up promotions. Some fixed editions are launch offers whose prices are published only for the offer window, not the full twelve-month term. Anchoring a year of comparison on one would leave most of that year with no price at all, and those days would vanish from your chart.
• Different products under the same umbrella. Heating and heat-pump tariffs, and export tariffs — not EV import tariffs at all.

Your region

Electricity prices differ by supply region, and the comparison uses the prices published for your region, worked out from the tariff you are actually on. If the chosen tariff published no prices for your region on a given day, that day is left off the chart. The tariff used for each day is named alongside its figures, so you can always see what you are being compared against.

How your charging is re-timed on the reference tariff

The reference tariff is Intelligent Octopus Go — the only reference tariff currently supported. It has two prices: a cheap rate through a fixed overnight window, 23:30 to 05:30, and a standard rate the rest of the time. Its selling point is smart charging — hand it the car, and it charges when electricity is cheap.

The charging is re-timed, not copied

Your car's actual charging times were chosen by this app for your tariff's cheap slots; copying those exact times onto the reference tariff would be unfair to it. So for each day the comparison takes just two facts — how much energy your car took at home, and how long it charged for in total — and re-times that charging the way the reference tariff's own smart charging would have placed it.

The day's charging is spread at its average power into slots, filled in a fixed order of preference, mimicking how the reference tariff's own smart charging would have placed for a typical car charge session:

1. The overnight window itself, 23:30 to 05:30 — six hours.
2. The shoulders either side of the window, nearest first: 23:00 in the evening alternating with 05:30 to 07:00 in the morning, and once the morning side is used up, backwards through the evening to 19:00.
3. Mid-morning to mid-afternoon, 10:00 to 16:00.
4. The morning peak, 07:00 to 10:00.
5. The evening peak, 16:00 to 19:00 — last of all, as the most expensive time to run a charger.

A day showing more than 24 hours of charging — possible when two cars charge at once — is treated as 24.

What gets the cheap rate

Until 1 August 2026, Intelligent Octopus Go's smart charging effectively extended the cheap window: a slot in which it charged the car was billed at the overnight rate even outside 23:30–05:30 — the car's energy and the household's use in that same slot. The comparison models this. On days before that date, every re-timed charging slot is priced at the cheap rate wherever it lands, and household use in those slots rides along at the cheap rate too.

From that date, the extension is retired — users started reporting the change around July 2026. Only the fixed 23:30–05:30 window is cheap: re-timed charging that spills outside it pays the standard rate, and household use is cheap only inside the window.

The household's side

Your meter measures everything together, so for each slot the comparison subtracts what the car was actually drawing at that time; what remains is your household's own use, priced at the cheap or standard rate by the rules above. The tariff's daily standing charge is then added to complete the day.

How fresh the figures are, and how far back they go

Why today is never on the chart

A day appears only once it is over and its numbers are final, so the newest day you could ever see is yesterday — and usually the chart ends a day or two further back than that.

The extra lag comes from your electricity supplier. Half-hourly meter readings are published with a delay, and the freshest readings are provisional: for around a day after first appearing they are still being revised, usually upwards. Showing a day built on provisional readings would mean quietly wrong figures that later disagree with your bill. So the app waits until a day's readings are fully published, then gives them a further day to settle. The result: the chart typically ends two days ago, and occasionally further back when your supplier is running late.

Worked out once, then remembered

Once a completed day's figures have been produced they are kept. Coming back to the chart, or widening the period, does not re-fetch or re-price months of history — only days never seen before are worked out. A day that turned out to have no data is remembered as such too, so the app does not keep re-asking your supplier about it.

Why an already-seen day can still change

When an update improves how a figure is worked out — a better comparison rule, a correction — days you have already seen are re-worked under the new rules the next time you look. That is the one way settled history changes, and it is deliberate: the chart always reflects the current best understanding of your data, not whatever rules happened to apply when a day was first shown.

What is kept, and how far back

Four kinds of record make up your history. Three describe the car and are kept for five years: the charging picture — your battery level, whether you were plugged in and at home, what the plan was doing and what the app had measured about your car's charging speed and battery use — the cabin temperature beside what the app was doing about it, and the two energy counts the car reports while it charges. The fourth is your recorded drives, kept for twelve months because those carry the places you drove between; the help on the drives the app remembers covers them.

None of it is written on a timetable. A fresh record is made every time something the app watches changes — a reading arriving from the car, a price update, a setting you edited — so your history is detailed while something is happening and sparse while the car sits still.

Five years is enough to compare a period against the same period the year before, several years running. After that a record is deleted, as the privacy commitments describe, and the clear-out runs nightly in the small hours. The period picker will not offer older dates, because the underlying records no longer exist.

Connecting your electricity supplier

The app needs to know what your electricity costs at each time of day, and it gets that by connecting to your supplier account. Octopus Energy is the only supplier currently supported.

What you provide

Two things from your Octopus account: your account number and an access key. The key is a read-only credential your supplier issues for exactly this purpose — it lets the app look up your tariff and your meter readings, and nothing else. Neither value is ever shown back to you in full once saved, and neither is sent anywhere except to your supplier.

What the app does with it

• Your prices. A rate for every half-hour slot ahead, which is what every charging decision is based on.
• Your meter readings. What was used and when, which is what the savings comparison is built from.

Why prices sometimes are not there

Suppliers publish upcoming rates on their own schedule, usually for the next day in the afternoon. Until they do, the app plans with the prices it already has and revises as soon as newer ones arrive — so a plan that looks unambitious in the morning often improves later in the day. If prices are missing for a period it needs to plan, it tells you.

Without a connection

The supplier connection is not optional. Without prices the app cannot plan anything, so until both your car and your supplier are connected it does not manage charging at all: no plan, no starting or stopping, no charging reminders, and the savings view tells you a supplier connection is needed. The app keeps pointing you at the integrations screen until both are connected. In the meantime the car behaves as it would without the app — typically charging as soon as it is plugged in, to its own limit, at whatever electricity costs then.

When it stops working

The usual cause is the access key being revoked or regenerated in your supplier account, which the app cannot detect in advance — it just starts being refused. When that happens the app stops managing charging, exactly as when no supplier is connected, and the supplier card on the integrations screen shows that the key needs re-entering; enter the new one and everything picks straight back up. Changing tariff needs nothing from you: the app reads the tariff from the account, so it follows you.

Using your calendar to plan charging

Connecting a calendar lets the app plan around trips you have already scheduled — charging enough beforehand, and warming or cooling the car in time.

You have to tell it which entries are car trips

This is the single most important thing to know, and the thing most people get wrong at the start: the app does not guess. An entry is only treated as a car trip if it has a location, a real start and end time, and one of these tags in its title or description:

• /car — this is a car trip.
• /leave 08:15 — this is a car trip and that is when you intend to leave. Use it when you know better than the app.
• /noc — this is a car trip, but do not precondition for it. One practical reason for using this is when the leave time is not precise, likely because your event's start time is approximate, and you do not want to precondition at an approximate time. Or you simply do not want the preconditioning for any other reason.

Any of the three marks the entry as a car trip, so there is no need to add /car alongside /leave or /noc. An entry with a location but no tag is ignored, and so is an all-day entry, which is almost never a journey.

If you write /leave without a time, or with something that is not a valid HH:MM time between 00:00 and 23:59, the app tells you so and falls back to working the departure out itself — it will not silently ignore a tag you clearly meant. You are told once for each thing that is wrong: a tag you have not got round to fixing stays quiet after that first mention, and if you change it and it is still wrong, the app tells you what is wrong with the new one.

How it works out when you need to leave

For a tagged entry without a /leave time, the app estimates the drive from your home location to the entry's location, and works backwards from the start time — allowing five minutes to park and walk in at each end. It prefers real evidence over a routing estimate: if you have driven something similar in the past few months, and that drive took roughly what this one should, it uses your actual time instead.

For a long trip — anything it estimates at over two hours of driving — it will suggest you add a /leave tag, because estimates that far out are not reliable enough to plan a departure on. For longer trips, you usually know when you leave more precisely than when you arrive. The app suggests it once.

Locations are matched to within a few hundred metres, so an entry whose address differs slightly from a place you have driven before still recognises the trip.

Turning an entry's address into a place on the map, and estimating the drive, use Google Maps. What is sent there is the trip itself — the address to look up, or the start and end points with the intended timing — and nothing else about the entry.

When a trip cannot be worked out — its address matches no place on the map, or the drive to it cannot be estimated — the app tells you once, naming the entry, and leaves that one trip out while planning the rest as usual. Where it was the drive that could not be estimated, the app keeps trying in the background, so a trip that failed for a passing reason appears on its own once it works; an address that matches no place is worked out again when you next edit the entry.

Several trips in a row

If tagged calendar entries overlap or follow each other closely, the app treats them as one chain instead of assuming you come home between them: drive out, stay for the first, drive on to the next, and only return home at the end. Charging is planned for the whole chain, which matters because there is no opportunity to charge at home in the middle of it.

A /leave time counts on the first entry of a chain only, because that is the one departure from home — everything after it follows on from when you get back in the car. If you have put a /leave on a later entry of a chain, the app tells you it is being left out.

What it works out you will use

Here too it prefers your own history: if you have driven between the same two places in the past few months, the app uses the battery those drives actually took. For trips that you did not do before, it works from the distance and its measure of how much battery your car spends per mile, and also allows for the charge a parked car quietly loses while you are there. Both of those figures are measured from your own driving — how that works, and what the app uses before it has enough history, is covered in the energy-use help. When a fresh measurement of either lands, the app works out its planned trips again from the new figure, so the amount a trip is expected to need can change without you having touched the entry. Either way, the result is what it adds to your Keep charge higher than setting when deciding how full the battery must be before you set off.

Housekeeping

You can connect more than one calendar and choose which of them to use. Nothing the app finds in your calendar is shown to anyone else or used for anything but planning your charging. The Google connection asks for read-only access to your calendars — the app can never change or add an entry anywhere.

Disconnecting a calendar from the app removes its trips from the plan: nothing new is picked up, and the trips it had already found drop out. Your charge targets are a separate feature and are untouched. If a calendar connection expires — most often because the account password changed — the app tells you once, and stops considering calendars of this particular calendar provider until you sign in again.

Connecting your car, and what to do when it drops out

The app talks to your car through the carmaker's own account, which is why you sign in to that account when you connect it. Currently, the app only supports connecting to Tesla cars and accounts. That connection is what lets the app see the charge level and start and stop charging; without it there is nothing to control.

Signing into a Tesla account, and the extra pairing step

For Tesla cars, signing in to your carmaker account is only half of it. The app also needs its virtual key added to the vehicle — a once-only pairing done at the car. Until that is done the app can identify your car but receives nothing from it and cannot act on it. Everything that can block this setup, and how quickly a fix made at the car is picked up, is covered in the help about the Tesla connection.

One car, one account

A car can only be controlled by one Joulary app account here. If you connect a car that another Joulary app account already controls, the app refuses the connection and says so. This is most likely to come up with a second-hand car, or a household where two people both set the app up. The previous account has to disconnect the car first — and the moment it does, your waiting connection completes by itself, with nothing to re-enter.

When the car is asleep

Cars sleep to save charge, and a sleeping car does not answer immediately. The app wakes it when it needs to act, patiently — how wake-ups are retried is covered in the help about how the app asks your car to do things, and why on-screen readings can look a little stale while the car sleeps is covered in the help about what the app can see.

When the connection breaks

The usual causes are the carmaker account password changing, the sign-in expiring, or the pairing being removed at the car. For the first two, as soon as the carmaker refuses the app it sends you a Car sign-in expired notification, and the Cars card says "Unable to authenticate with Tesla. Log in again." A pairing removed at the car is different: the app is still signed in, so no notification is sent — the card shows your car with a Pair your vehicle button when you next look. Either way, until it is fixed the app cannot start or stop charging, so the car does whatever its own settings say, which is normally to charge as soon as it is plugged in, at whatever the electricity costs then.

Reconnecting is the same flow as connecting the first time. Your settings, charge targets and history are untouched by a disconnection.

How the Tesla connection works

The app does not poll a Tesla on a schedule — the car streams its readings, each on its own cadence, chosen to balance freshness against keeping the car awake:

• Changes of state — charging started or stopped, plugged in or out, gear, climate on or off, the charge limit — arrive within about a second of happening.
• Battery level, cabin temperature and speed report every half minute, and only when they actually changed.
• Position reports every half minute.
• The odometer reports at most once a minute, and only once another mile has been covered — enough to measure the length of a drive.

The car counts as reachable while its stream says it is connected, or while any reading has changed within the last ten minutes — a belt-and-braces rule, because the stream's own connected flag is not perfectly reliable. A car silent for longer is treated as asleep/offline.

What can block the setup

Three conditions stop the connection working, and the app names each one instead of failing silently:

• Your Tesla account must contain exactly one vehicle. None, or more than one, is reported as not supported.
• The virtual key must be added to the vehicle — the once-only pairing done at the car. Until then the app can identify the car but the car will not accept its data requests or commands.
• Tesla limits how many apps one vehicle can stream to. If that limit is already used up by other apps, the app tells you; removing one of them at the car frees a place.

While either of the last two blocks setup, the app re-checks every fifteen seconds so fixing it at the car is picked up almost immediately; once everything works, the check drops to hourly. If the car is set up but nothing at all arrives, the app queries Tesla for the reason and tries one wake-up — once, not repeatedly.

Commands and sleep

Commands are only sent while the app can see the car's own reporting — a command whose effect could not be observed would be a shot in the dark. If Tesla reports the vehicle is offline, the app wakes it first and then retries the command by itself. A command whose effect the car is already reporting — a charge limit it already has, a wake-up for a car already awake — counts as success straight away.

Notifications the app sends

The app notifies you only when there is something you would want to act on. Tapping a notification about your charging or a connection opens the card it is about. Notifications go to every device you are signed in on, and one about your charging that cannot be delivered within an hour is dropped instead of delivered stale — a "plug the car in" arriving after the cheap slots have gone would be worse than silence. The one about your account being deleted is different: it waits for a phone that is switched off or out of coverage for as long as it can, up to about four weeks.

What it will tell you

• Plug the car in — charging is scheduled and the car is not plugged in. The most common one, and the one with the most thought behind its timing.
• Charge shortfall — it cannot get you to a target or a trip in time.
• Charge target skipped — a charge target was ignored because it clashed with a trip; the trip wins, because the car cannot charge while you are driving.
• No prices available — your supplier has not published prices for the period being planned.
• Journey error — something is wrong with a calendar entry: a /leave tag it could not read, or a place it could not find. You are told once, and told again if the problem clears and later comes back.
• Journey advice — there is something worth doing, such as adding your departure time to a long trip. You are told once for that entry.
• Wake up failed — the car did not respond when the app tried to reach it.
• No power — the car should be charging and is plugged in, but no power is flowing. Usually the charger, the cable, or the supply.
• Manual charge could not start and smart charging not resumed — an action you asked for did not take effect.
• Calendar sign-in expired — a connected calendar needs signing in to again. Until you do, trips from it stop being picked up.
• Car sign-in expired — your Tesla account needs signing in to again, most often because its password changed. It arrives as soon as Tesla refuses the app, and until you sign in again the app cannot start or stop charging.
• Account scheduled for deletion — a deletion of your account has been scheduled, and this says the date and time it will happen. It is the companion of the email that says the same, so that if somebody else scheduled it you hear about it even if that email never reaches you. Tapping it opens the account's deletion screen, where Cancel Deletion is unless an operator scheduled the deletion. It also arrives when an account is due to be deleted for going unused, and then it says to sign in to keep it — which on its own is enough, with nothing to tap. What follows is covered in the help about deleting your account.

When the plug-in prompt arrives

The app tries to reach you at a moment when you can actually act, not at a fixed time before charging.

• If charging starts overnight — between your Bedtime and Wake-up time settings — it tells you an hour before your bedtime, not in the middle of the night. The point is to catch you while you are still up and can walk out to the car.
• If charging starts during the day, the reminder arrives before the charge is due to start, by the amount of time in your Plug-in alert advance notice setting.

Your Bedtime, Wake-up time and Plug-in alert advance notice settings are all yours to change.

Why it does not nag

Several rules keep it quiet:

• Unplugging is not immediately a problem. When you unplug at home the app waits about twenty minutes before saying anything, because unplugging is usually the start of leaving. If you are still at home and still unplugged when that passes, it does prompt — you may yet want that charging slot.
• A repeat is suppressed while the planned start stays roughly where it was. Prices and charge level shift the ideal start by a minute or two constantly, and you do not need telling each time.
• A late prompt says so. If charging was already due to begin, the wording changes to tell you that you can still catch what is left of the slot instead of implying you are on time.

Turning them on, and off

The app never asks for the notification permission on its own. Once your connections are set up, a card on the Home screen headed Get alerted when the car should be plugged in offers Enable notifications, which opens the phone's own permission question, and Not now, which puts the card away for a month. Notifications are a system permission: if you decline them, the app carries on charging exactly as it would have, it just cannot tell you about it — including that the car is not plugged in. Changing your mind later is done in the phone's settings for the app.

Emails Joulary sends you

Joulary emails you only when something important changes about your account itself — not about your charging, which is what notifications on your phone are for. There are five of them, and most people will only ever see one.

What it will email you about

• Your Joulary account is ready — sent once, when your account is first set up. It says which way you sign in, so an account somebody else created in your name is obvious.
• Your account will be deleted on a date — sent when a deletion is scheduled, giving the exact date and time it will happen and how to stop it. The same warning also arrives as a notification on any phone where you are signed in to Joulary and have allowed its notifications, so an email that goes astray is not your only copy of it. If the date ever moves, you get the message again with the new one, so the most recent of these is the one that counts.
• Your account will be deleted on a date unless you sign in — sent when an account has gone unused for long enough to be scheduled for deletion on that ground. It arrives about two months before the date, and signing in is all it takes to stop it. What counts as using the account is covered in the help about deleting your account.
• Your account will not be deleted — sent when a scheduled deletion is cancelled, whether you cancelled it yourself or an account that had gone unused came back into use.
• Your account has been deleted — sent once the erasure has actually run. It is the last thing you will ever get from us.

Separately from these, you get a confirmation email when you create an account with an email address and a password, and a password reset email when you ask to reset a forgotten one. Both come from the sign-in service Joulary uses, not from Joulary itself, so they look different from the four above. If you signed in with Google or Apple you will never see the confirmation one, because they have already confirmed the address.

Why you cannot turn them off

There is no unsubscribe link, and that is deliberate, not an oversight.

Every one of these emails exists because something happened to your account that you would want to know about even if you did not ask. The clearest case is the deletion warning: if somebody else got into your account and asked us to delete it, that email and the matching notification on your phone are all that stand between them and everything you have stored. Somebody who had turned emails off, with no phone allowed to show Joulary's notifications, would get seven days of silence and then lose the lot.

So they are not something you opt into, and there is nothing to opt out of. In exchange, we keep the set small and keep it strictly to your account. Joulary will never send you marketing, newsletters, offers or product announcements, and nothing of that kind will ever be added to these emails — which is also why they need no unsubscribe link to be lawful.

Whether Joulary can tell you opened one

Joulary's emails are delivered by Brevo, and Brevo adds tracking to every message it sends that Joulary cannot switch off. Each email carries a small invisible image that is fetched when the message is displayed, and each link in it goes to Brevo first before forwarding you on, so Brevo can record that a message was opened, roughly when, and which links were followed. Brevo's anonymisation setting is switched on, so those records are stripped of who you are.

Joulary does not read them, does not build a picture of you from them, and does not change what it sends based on whether you opened anything. If you would rather not be counted at all, most email apps block remote images until you ask for them, which stops the invisible image loading, and you can copy a link's address instead of tapping it. The full account of this is in the Privacy Notice, linked from the account (person icon) screen.

If you get one you were not expecting

Take it seriously, and do not use any link in it if you have any doubt the email is genuine.

• A confirmation email for an account you did not create — ignore it. Nothing has been set up, and the address is released after seven days.
• A password reset you did not ask for — ignore it. Your password does not change until somebody opens that link, and nobody can do that without getting into your inbox.
• A deletion you did not schedule — somebody else is in your account. Secure it straight away, and if you cannot get back in, reply to the address in the footer.

Joulary will never ask you for your password, in an email or anywhere else. The emails Joulary sends you say so in their footer, and the confirm-your-address and reset-your-password ones come from the sign-in service instead, so they look different and carry no such footer.

If an email does not arrive

Check your junk or spam folder first, and add the sender to your contacts if you find one there. Asking for a confirmation or a password reset email again is covered in the signing-in help.

If you use Hide My Email with Apple, our emails go to the relay address Apple gives us, not to your real one, so check that relay if nothing has arrived.

The deletion emails are the ones worth watching for. If you have scheduled a deletion and want the record of it, keep the email: once the erasure has run there is nothing left in the app to look at.

Signing in, and who can register

There are three ways in: an email address and password, Continue with Google, or Sign in with Apple. With Google or Apple there is no separate registration — your account is created the first time you sign in. With an email address you register first: Create account at the bottom of the sign-in screen asks for your name, your email address and a password, then sends you a verification email, and you can sign in once you have followed it. A checklist under the password field ticks off each rule as you type — at least 8 characters, a lowercase letter, an uppercase letter, a digit and a symbol — and the Create account button stays greyed until all five are ticked. Whichever way you signed up, signing in again from any device reaches the same account.

Every one of these screens also carries Trouble signing in?, which opens this help in a browser — it needs no sign-in, so it is there for exactly the moment you cannot get in.

On the sign-in screen, under it, Contact support reaches a person. Signed out there is no account to attach a message to, so it opens your email app addressed to support@joulary.com; the address is shown as text beside the link as well, so you can copy it if your phone has no email app set up.

Signing in is not quite instant once your password or your provider has accepted you: the app checks the state of your account before it can show you anything, which normally takes a moment. The Sign in, Continue with Google and Sign in with Apple buttons all stop responding while it does, and the one you used shows a spinner — except Sign in with Apple, which is Apple's own button and only dims. So a pause after a correct password is the app working and not a tap that missed. Creating an account with an email address skips this and goes straight to verification.

Once the account exists you get one short email confirming it is set up and saying which of the three ways you sign in. It is worth a glance: it is how you would notice an account somebody else created in your name.

Signing in does one more thing worth knowing about: if the account was due to be deleted for having gone unused, doing so calls that deletion off, with nothing to tap. The help about deleting your account covers when that happens and what you are told beforehand.

When a first sign-in is refused

A few first sign-ins are turned away, each for a specific reason:

• The email address is unverified. Verify it with the sign-in provider and sign in again — the account is created then.
• The email address already belongs to another account. This happens when the same address sits behind two different sign-in identities — say a Google sign-in and an Apple sign-in that both use it. It cannot be resolved by retrying; it needs support to reconcile the two.
• Too many new accounts at once. Rare, and trying again later works.
• A reserved or blocked email domain. Addresses at domains that cannot receive mail, plus any domain an operator has blocked.

An existing account is never refused for any of these — they apply to creation only.

Verifying your email address

After Create account, the app moves to a Verify your email screen and stays there until the address is confirmed: follow the link in the email it names, then press I have verified. That button reads Checking… while it looks, and keeps reading it through the same short account check as a sign-in, so it stays that way right up to the moment the home screen replaces it. Resend email sends the link again — after a send it shows a one-minute countdown before it can be pressed again, so give the first email a moment to arrive (and check the spam folder). Use a different account signs you out and returns to the sign-in screen.

A forgotten password

Forgot password? on the sign-in screen leads to a Reset password screen: enter your email address and press Send reset email, and a reset link is emailed to you — the screen confirms with "Password reset email sent. Check your inbox." Set the new password by following the link, then sign in with it. This applies to accounts created with an email address and password; a Google or Apple sign-in has its password managed with Google or Apple.

Sessions

Your sign-in lasts until you sign out, your password changes, access is revoked with the sign-in provider, or the account is erased — an erased account stops being signed in anywhere, and signing up again with the same email address starts a new account that your old sign-in does not carry over to. Signing in freshly is demanded for one thing only: requesting account deletion.

A brand-new account starts on UK time

Until the app reports your device's timezone — which happens on first contact — a new account defaults to UK time. If times ever look shifted right after setup, that is why, and it corrects itself as soon as the app connects.

Taking your data out, and deleting your account

Both of these live on the account screen, behind the person icon, and both act only on your own account: Export my data and Delete account.

The export

Asking for your data produces a single downloadable file containing everything the app holds about you: your profile, the sign-in identities linked to the account, every setting, any support messages you have sent, and all recorded history — the charging and energy records, drive records, everything, however many years of it there are.

Three honesty details about the file. Stored secrets — the keys and tokens behind your connections — are marked as present but their values are never included; an export is a record of what is held, not a way to extract credentials. Support messages appear with what you wrote and what has happened to them; where you chose to attach technical details, the file records that you did without repeating them. And the history is written straight through as read, so a very large export downloads steadily instead of appearing all at once.

One export runs at a time per account, and a few at a time across everyone — a second request while one is running, or at a busy moment, is asked to retry shortly. A download read impossibly slowly is eventually abandoned instead of being allowed to run forever.

Deleting the account

Deletion is deliberately a little ceremonious, because it is permanent:

1. You must have signed in within the last five minutes. A stale session is asked to sign in again first — proof that the account's owner, not someone holding an unlocked phone from hours ago, is asking.
2. A seven-day grace period follows. The app replaces itself with a single screen headed Account scheduled for deletion, which names the exact date your data will be erased. Nothing is erased yet, and the rest of the app waits until the deletion is settled one way or the other — but that screen still offers Export my data, so you can take a copy away without cancelling first, Help with account deletion, which opens this help in a browser, and Contact support, which is how to reach a person if you need the deletion undone after the window has closed.
3. During the grace period you can change your mind. Cancel Deletion, on that screen, revives the account exactly as it was. One nuance: you can cancel a deletion you requested; if an operator suspended the account for cause, the screen says so and undoing it is the operator's decision, not yours.
4. You are told at each step — when the deletion is scheduled, giving the exact date, by email and by a notification on any phone where you are signed in to Joulary and have allowed its notifications; if it is cancelled, by email; and once the erasure has actually run, by email. Those messages are how you would find out if somebody else scheduled a deletion on your account, so they are worth reading instead of filing.
5. After the grace period, everything is erased permanently — profile, settings, connections, any support messages you sent, and all recorded history. If you ever signed in with Apple, the link to your Apple ID is revoked as part of it, which is why the app asks Apple for a long-lived credential at each Apple sign-in: deletion runs days later, when the sign-in itself has long expired. The erasure retries until every step has completed, so a technical failure delays your data's removal without leaving any of it behind. Unlinking your Apple ID is the one step that is not retried: if Apple refuses it, your data is still erased on schedule and the unlink is finished by hand.

If you stop using Joulary

An account that goes unused for about two years is deleted, because keeping your data once nothing is being done with it serves no purpose. Two things count as using it, and either one is enough: opening the app, and Joulary actually doing something for your car — starting a charge it planned, or running the preconditioning it committed to. So an account that is quietly charging your car every night goes on being used even if you never open the app, and the clock does not start until that stops too.

You get a long warning. About two months before the deletion date, Joulary emails you saying the account will be erased on that date unless you sign in, and sends the same warning as a notification to any phone where you are signed in and have allowed notifications. The account is put on hold for those two months — the app shows the same Account scheduled for deletion screen, and charging control stops — so the warning is hard to miss if you do open it.

Once the warning has gone out, signing in is what keeps it — and it is all it takes: the deletion is called off the moment you do, with nothing to tap, and Joulary emails you to confirm the account is staying. Joulary doing something for your car cannot keep it at that point, because the account is on hold and Joulary has stopped controlling your charging; until the warning, either counted. That email is worth reading even though the news is good: if you were not expecting it, somebody else has been in your account.

Your data, and what the help assistant can see

The app keeps what it needs to charge your car well: charge levels and charging history, the targets you have set, the connections you have made, and the journeys it has worked out from your calendar.

You can ask for a copy of everything the app holds about you, and you can ask for your account and its data to be deleted, both from the account (person icon) screen. Deletion removes your data after a short grace period during which you can change your mind.

The help assistant you are talking to now is deliberately given very little, and it is given it only when your question needs it. It always sees this help material, which is the same for everybody, and with every question the name of the screen you opened help from, as the help screen shows it after Help for: the title at the top of that screen, followed on Settings by the tab you had open.

When your question is about your own car or what you pay, it also looks up what your own screens are showing. The first of those is your home screen at that moment: the charging mode, what the car reports, whether it is plugged in and at home, its charge level, any reminder the screen is showing you to plug in, the charging the plan has booked and when, the short note beside each booked block saying why the app put it there, the line saying why the plan stops where it does, the temperature in the cabin, the line saying what the app is doing about that cabin before your next trip, and the figures the app has measured for your car. Alongside those it gets the trips the plan is charging for, as the Timeline chart marks them: when each one leaves and when you are expected back, how much charge it should use, and whether that came from your own past drives, from the route, from the time you are away, or from the car sitting parked. It also gets the charge levels the chart's line passes through: how full the app expects your car to be before and after each booked charge and each trip. It gets your upcoming charge targets too, without their names: when each one falls, the level you set and your answer to Needed?, as the home screen shows them, and from the Timeline chart the level the plan charges for given that answer, how full the app expects your car to be then, and whether the target is Inactive because a trip at the same time takes its place. When a Long Term plan has no charging in it because nothing ahead needs any, it is also given one fixed sentence saying so, the same for everyone and carrying nothing about you.

The second is the electricity prices the Timeline chart is drawing, looked up whenever prices bear on your question — what you pay, and why the plan charges when it does or not at all: what you are paying now, where the supplier's published prices end and the app's own forecast begins, and for each day ahead the cheapest, dearest and average price with the cheapest two-hour stretch in it, along with the cheapest stretches anywhere ahead. It gets the chart's conclusions, not the curve behind them — the same figures you would read off the chart yourself, each carrying the day and time it applies to, so it quotes the figure the chart shows you.

One part of your picture reaches backwards and the rest of it does not: the measured figures, worked out from your own past driving, charging and parking, which is why it can tell you what your car typically uses, how fast it charges, and what it loses while it sits. Everything else it is shown is how things stand now and what is planned next, so it has no record of what your car did earlier — whether it charged overnight, what the prices were this morning, what it was doing yesterday, or why something happened at a time that has gone by. Ask it one of those and it will say so. Your own recent readings stay yours to look through on the home screen's Energy card.

That is the boundary, and you can check it yourself: if it is not on one of your own screens, the assistant was not told it. The third is the settings you have chosen: what you charge to and by when, the levels it keeps your charge between, what counts as a good price, how much battery wear it may spend keeping the charge unusually full and how close to the time you need it a charge to full may start, how far ahead it plans, when it warms the cabin, the period your savings figures cover, and when it may ask you for the cable — which includes your Bedtime and Wake-up time settings, because those are what decide when a plug-in reminder is due. Each one arrives as the label the settings screen shows and the value you would read beside it, so you can check that too. It is also told which kinds of connection you have set up, named only as "car", "calendar" or "energy supplier". Ask how a feature works in general and it looks up none of them.

It is not given your home or car location, the contents or titles of your calendar entries, which calendars you chose to use, the names you gave your charge targets, your email address, your passwords, or any key or token belonging to a connected account. When it is told the app has booked a charge for Tuesday morning, it is told the time, the charge, the price, and which kind of need booked it — the same trip or yummy note the Schedule table prints. Which trip stays behind: a calendar entry's title and its location are never sent, so the assistant can tell you a charge is for the trip that leaves at nine on Friday without knowing what that trip is. The cabin line works the same way — it can say your next trip is too far ahead for the app to start warming the car, and it is never told what that trip is. A charge target reaches it as its time and levels, and the name you gave it stays behind. It cannot change anything, cannot start or stop a charge, and cannot see any other user's data.

Answering questions does send your question, and anything it looked up, to Anthropic, who run the language model that writes the answer, under terms that forbid using either to train models and that delete both within 30 days. If you would rather that did not happen, turning the help assistant off in settings stops it entirely; everything else in the app works exactly as before.

When you write to us, the Contact support link opens a message box, and what you type there is kept so a person can read it and answer you. Sending it gives you a reference, and the reply comes to the email address on your account, usually within a few working days. Two switches under the box decide what goes with the message, and both show you what they will send before you send it. Leaving the screen with something unsent offers to discard it; nothing you have not sent is kept.

Attach technical details is on to start with, and the screen lists underneath exactly what it means: your phone model and its operating system, the app version, your language and time zone, which screen you came from, when the app last heard from your car, and when this was taken. The time zone is there because so much of what the app does turns on what time it is where you are, and a question about the car charging at the wrong moment is close to unanswerable without it. None of it says anything about you as a person — it describes the phone, the app and which time zone you were in when you wrote.

Attach your conversation with the assistant is off to start with, and appears only when you have been talking to the help assistant. Turning it on sends the last few things said on both sides, shortened if any of them ran long. What the box shows you underneath is exactly what would go.

Once we have answered and closed your message, it is deleted thirty days later, along with anything you attached. A message in which you asked us to do something with your own data — send you a copy of it, correct it, delete it — is kept past those thirty days, so that what you asked for and when you asked it cannot go missing. Your messages are part of the copy of your data you can ask for from the account (person icon) screen, and deleting your account takes every one of them with it.

If you are signed out, Contact support opens your own email app instead, addressed to support@joulary.com with those same technical details written into the message for you to read before you send it. A message sent that way lives in our mailbox like any other email, so the thirty days above do not apply to it: the whole conversation, your emails and our replies, is deleted automatically 120 days after its last message. As with the message box, one in which you asked us to do something with your own data is kept longer, so that it cannot go missing.

Reaching a person

The assistant and the Manual are meant to answer most things. When they cannot — you cannot sign in, another account already claims your car, you want a deletion undone, or something is simply wrong — there is a way to reach a person.

Where the link is

It reads Contact support everywhere, so you are looking for the same words each time:

• On the help sheet, on its own line beside Manual, under the title and the Help for line naming the screen you came from. It is there whether or not you have switched the assistant on.
• On the sign-in screen, under Trouble signing in?.
• On the deletion screen, under Help with account deletion.
• On the Joulary website footer.

Signed in: sending a message from the app

Tapping the link opens a screen where you write how we can help. Up to two things can be attached to it, and you decide each. Which of them you are offered depends on where you came from: the conversation only appears if you had one, so reaching support from the help sheet after asking the assistant something offers both, and reaching it from the deletion screen offers the technical details alone.

Attach your conversation with the assistant — off unless you switch it on. The screen shows you the conversation first, exactly as it will be sent, so you can see what you are sending before you send it. It is off by default because you may have typed anything into it, and that is yours to share or not. Only the last few turns travel, and a very long one is shortened — you will see it ending in … on the screen, so what is shown is still exactly what is sent.

Attach technical details — on by default, and you can switch it off. This is what your phone can say about itself: the phone model, its operating system version, the app version, your language and time zone, which screen you came from, when the app last heard from your car, and when the reading was taken. That one about your car is often the whole answer when the app is showing nothing or showing something stale. That list is the whole of it — nothing else about you goes with the message, and nothing else needs to, because we already hold what we need on our side.

Your message can be up to 2000 characters, and you can send up to ten a day. If you reach that, wait until tomorrow.

If you leave the screen with something written and unsent, you are asked whether to discard it first — the message is not kept anywhere until you send it.

Your reference

When the message is sent, the screen shows a short reference such as ABCD2345, which you can select and copy. Quote it if you write again, so we can tie the two together. It is not something you can look up: there is no screen that shows your messages back to you, and we do not send a confirmation email. The reply itself is how you will know we have it.

We usually reply within a few working days, to the email address on your account.

Signed out: when you cannot get in

If you cannot sign in, there is no account to attach a message to, so the link opens your email app instead, addressed to support@joulary.com with the technical details already filled in. You can edit or delete any of it before you send.

The address is also shown as text beside the link, so you can copy it. If your phone has no email app set up, nothing opens and the text beside the link changes to say so, naming the address to write to — that is exactly the situation someone locked out is often in, so the address is never hidden behind the link alone.

Nothing about your account goes into that email automatically. If you are writing about an account you cannot reach, say which email address it uses, and expect us to check that it really is yours before we change anything on it — a message alone is not proof of who sent it, which protects you as much as us.

An email sent this way stays in our support mailbox, and the conversation is deleted automatically 120 days after its last message; one asking us to do something with your own data is kept longer, so we can show we handled it. The rest of this page is about messages sent from inside the app.

What happens to your message

Your message and anything you attached are stored on our own systems, not with a third party, and are read only by the person answering you.

Once a message is dealt with and closed, it is deleted 30 days later. If your message was a request about your own data — asking for a copy, or asking to be deleted — it is kept longer, because we have to be able to show we handled it.

Your messages are included when you Export my data, and they are deleted with everything else if you delete your account. The export shows what you wrote and what happened to it; where you attached technical details, it records that you did without repeating them.

Replies come from support@joulary.com and continue in ordinary email from there.

The help assistant's own rules

A few rules govern the assistant you are talking to right now, and they are worth knowing because they explain every way it can decline to help.

Off until you say otherwise

The assistant is off by default and stays off until you switch on your AI help assistant setting, which is on the Misc tab of settings — and also on the help screen itself, which shows you the same wording and the same switch until you have turned it on. That switch is a real consent: while it is off, questions are refused on the server itself, so nothing about you is sent to the language-model provider no matter what a device asks. Switching your AI help assistant setting off again stops the assistant entirely, and everything else in the app carries on as before. What is and is not sent when it is on is covered in the help about privacy and your data.

The daily allowance

Each account may ask fifty questions a day. That is a safety net against a runaway or abusive client, not rationing — far above any plausible run of genuine questions, so meeting it in normal use is essentially impossible. Over the allowance, questions are refused until the day rolls over.

Why a question can get no answer

• It is not about this app. The assistant answers questions about this app and your charging, from its own help material — it is not a general-purpose assistant, and it declines everything else.
• It could not ground an answer. Every answer must rest on the assistant's help material, or on what your own screens are showing at the time, or on both; an answer resting on neither gets discarded before you see it, and you get a "cannot answer" instead. A wrong-but-confident answer about your car is worse than a refusal, so the bar is deliberate.
• The question covered too much at once. A question reaching across most of what the app does can come back as "cannot answer". One thing at a time works better.
• The assistant is switched off, or the daily allowance is spent — both described above.

Which screen you are on

The help screen names the screen you opened it from, under its own title: Help for Timeline, say, or Help for Settings › Integrations, which adds the settings tab you had open, or the name of the setting you were changing. The assistant is told that same name with every question you ask there, so "what does this screen show?" or "which screen am I on?" is answered about the screen you came from.

What it remembers

A conversation is only as long as the screen you are looking at: your most recent few questions travel along with a new one so follow-ups make sense, and that is the whole mechanism — the assistant keeps no record of the conversation between questions, and no memory of past conversations.

There is one way a conversation is kept, and you choose it: on the Contact support screen you can attach the conversation to the message you send, and then the last few turns of it are stored with that message for the person answering you. It is off unless you switch it on, and the screen shows you exactly what would be sent before you send it.

The Manual

Everything the assistant answers from is also a page you can read for yourself. Manual, at the top of the help screen, opens it in a browser at the part about the screen you were on when you tapped the question mark, with an All topics list you can open at the top and a search box above it. It needs no sign-in, so the sign-in screens offer it too, as Trouble signing in?, for anyone who cannot get into the app.

Beside it, Contact support reaches a person — for the questions neither the assistant nor the Manual can answer, most often something about your own account and not about the app.

Under an answer you will often see Topics consulted and the names of the parts of the Manual the assistant read before writing it. Tap one to open the Manual there and read it in full. An answer about your own car — what it is charging to, whether it is plugged in — usually reads nothing from the Manual, so it shows no names at all.