The obvious problem

• Climbs cost more. Driving uphill takes more battery %. Going downhill can take a little, none at all, or give some back through regen.
• Speed costs more. Higher speeds, like on the highway, cost the most. Slowing down gives some back through regen.
• The devil is in the details. Those are the obvious ones. I've solved the problem of accounting for situations like these and more, so the model learns how your vehicle responds in each of them.

The model is yours

• One model per driver. Your predictions come from a model that learns only from the drives you record, in your vehicle. It is not an average of everyone who owns the same vehicle.
• A vehicle's own estimate can't tell you that. A manufacturer's arrival % gives you no way to see whether it is tuned to you or to all its drivers, or whether it is getting any better.

What it learns about you

• How much battery % your vehicle uses on climbs and descents, at different speeds, and at different temperatures.
• How much battery % your vehicle uses while stopped during a trip, with heating, cooling and its other systems running.
• Seasons. Temperature strongly affects an EV's battery. The more seasons you record in, the more of the year it knows.

How it gets better

• Your first prediction comes from physics. Before you've recorded a drive, the app works out the battery % from the physics of moving your vehicle over the route. From the first drive you save, the predictions come from your own model.
• Every recorded drive teaches it. When you save a drive, the model is updated from the battery % your vehicle actually used.
• The cost: you have to connect your vehicle and record your trips. It gets more accurate the more you record.

Record your drives

• Every drive you record teaches your model. Trips you don't record teach it nothing, so the more you record, the better its predictions get.
• Record it yourself, or let a planned trip record itself. Plan the trip first and turn on Hands-free in Settings: a planned trip then starts recording when you set off, and stops and saves when you arrive.

On the web app, keep it open

• Keep the app open and the screen on while you drive. Your route comes from your phone's GPS. In a browser, on any phone, Android or iPhone, a drive only records while the screen is on.
• If you install the Android app, you don't need to. It keeps recording with the screen off.

• Arrival battery %. Plan a route on the map and it tells you the battery % you'll arrive with.
• Charging stops. Turn chargers on (the ⚡ button in the search bar) and the plan includes where to charge. You set the battery % you want to arrive with, how full to charge, the slowest charger you'll accept, and which networks.
• The region you can reach and still get back from. Cache a region on the map, either a square around you or a strip along your route, and it shows how far you can go in it and return.
• The weather. A planned route uses the forecast along the way, for the time you'll be at each part of it. When you cache a region you pick the day, up to sixteen days ahead, and it uses that day's forecast temperature.
• Cached for offline, when you choose. Saving a route or a region puts it in your account. To use it with no signal you also cache it on your phone, from the Cached Maps page.

It plans with real speeds

• Speed limits, road by road. Speed changes how much battery % a route uses, so the app plans with the posted speed limit of each road on your route.
• Then your own speeds. Once you've recorded enough on a category of road, such as highways or residential streets, it plans with the speed you typically drive there in place of the limit.

• The prediction stands. It is made before you leave and doesn't change. If you take a different road, only the new part gets a new prediction.
• Hands-free, if you turn it on. It is off unless you switch it on in Settings. Then a planned trip starts recording when you set off, and stops and saves when you arrive.
• In a cached region with no signal. The map and the predictions you cached still work.
• If the signal drops mid-drive. The phone keeps recording and still knows which road you're on along your route, because the roads beside it were stored when you planned. When you stop, the drive is saved on the phone and sent once the signal is back. The one thing it can't do without signal is plan a new route if you leave yours.

• Working today: Rivian and Hyundai. You sign in to your vehicle's account and the app reads the battery % from it.
• Any EV can be added. The model isn't built per manufacturer; it learns whatever vehicle you drive from your recorded drives. A new manufacturer only needs its connection added.
• Next most likely: Kia and Genesis. They use the same connected-vehicle network as Hyundai. The Kia connection is started but not finished.
• Others need an owner to test with. VW's sign-in is currently blocked, and Tesla requires approval as a partner before a connection can be built. If you drive one and want yours connected, say so in the access request below.
• More than one vehicle. An account can hold several vehicles; you pick which one is active, and recordings go to that one.
• Try it first. A demo vehicle lets you use the app without connecting your own.

• It's a web app. It runs in the browser on a phone, tablet or computer, and can be added to a phone's home screen. Nothing to install from a store.
• Android app. The same app, and it keeps recording with the screen off.
• One limit: in a browser, on any phone, Android or iPhone, a drive only records while the screen is on. There is no iPhone app.

• Privacy, on by default. Where you drove is deleted once the drive is saved. The app keeps distance, elevation, speed and energy. You can turn that off.

Some key services are free ones, and that shows sometimes

• Routes can look odd. The route line comes from a free public routing service. The app doesn't draw routes itself, so an odd route is that service's choice.
• The first prediction after a break can be slow. The prediction engine runs on a free server that goes to sleep when unused. Waking it takes most of a minute, and the app tells you it is waking. After that, a route's prediction comes back in seconds.
• Caching a region takes minutes, once. A cached region is a square around you, or a strip along your route, that you choose to store. The first time, the app gathers that region's elevation and roads from free services that only allow slow requests. Once it is cached, everything you ask about that region is answered straight away, including with no signal.
• A service can be down or slow. Routing, elevation, roads, weather, place search and chargers are all free outside services.

What the app does about that

• Every one has a backup. Routing, elevation, place search and chargers each have a second source the app switches to.
• Answers are kept. Once an elevation, a road or a forecast has been fetched, it is stored, so the same place isn't asked for twice.
• It never fills a gap with a made-up value. If the weather or road data can't be had, the app records it as missing.
• A recorded drive is not lost to any of it. A drive is stored on your phone first, and the work on it is retried until it goes through.

You have to record your trips

• Recording is how it learns. With your vehicle connected, each trip you record teaches the model. Trips you don't record teach it nothing.
• It is less accurate at first and improves with each recorded drive.

It is not an official connection

• No manufacturer has approved the app. It signs in with your own login, the same way your manufacturer's own app does. Because of that, your manufacturer could change or block it at any time.

Read only: what the app uses

The connection is read only. The app only ever asks your manufacturer for information; it never sends your vehicle a command (see What it cannot do, below). Whatever your manufacturer, it uses only these:

• your battery % (some manufacturers that also build gas vehicles call it fuel level)
• the range left, and the battery's size
• whether the vehicle is charging, and whether it is plugged in
• when the vehicle last reported
• your vehicles' names and their IDs at your manufacturer, so you can pick one and the app asks about the right one

The most the app may keep

The app never asks for anything beyond the list above, and still only reads. But some manufacturers can only be asked for the vehicle's status as a whole, and send everything in reply. From such a reply the app may keep these too, because they bear on what a drive uses:

• the odometer, and tire pressure
• heating and cooling and their set temperature, defrost, and heated seats, steering wheel and rear window, which draw on the battery while you drive
• whether the vehicle is switched on, and whether it is parked or in drive

Nothing else is kept. Of anything else such a reply holds (doors, locks, windows, lights, the vehicle's position), the app keeps only the names of what was sent, never what it said.

• When it asks. About every 10 seconds, while you record a drive or have a screen open that shows your battery. Close the app or put it in the background and it stops asking within 30 seconds.
• Not your vehicle's make, model or year. Those are what you pick when you add the vehicle in the app; it doesn't ask your manufacturer for them.
• Not your location. Your route comes from your phone's GPS, not from your vehicle.

By manufacturer

What it cannot do

• There is no code in the app that controls a vehicle. It cannot lock or unlock, start or stop, heat or cool, start or stop charging, change a charge limit or schedule, honk or flash the lights, or change any setting in your vehicle or your account.
• It does not wake your vehicle. Where a manufacturer can be told to wake the vehicle for a fresh reading, the app asks for the last reading the manufacturer already holds instead.

Your password is never kept

• You type it once. It goes straight to your manufacturer over a secure connection. Your manufacturer checks it and sends back a pass, a long code that means "this person has signed in". The password is thrown away and is saved nowhere, not even encrypted.
• The pass is locked. It is saved encrypted and never written to a log. When it expires, the app swaps it for a new one, so you don't sign in again.
• What else is saved, and why. Your account's email, to show you which account is connected. The vehicle's ID at your manufacturer, and where the manufacturer needs it the VIN, to ask about the right vehicle. A manufacturer that asks for a PIN on every reading has it saved inside the encrypted pass.

Disconnecting deletes the sign-in

• Disconnect is on the vehicle's card, in Profiles & Devices. It asks twice, then deletes the pass, any PIN, your account's email, the vehicle's ID and VIN, and the record of what your manufacturer answered. From then on the app cannot reach your account.
• What stays is what you recorded: your drives, and what the app learned about your vehicle from them. Delete a drive yourself from Trips, or the vehicle from its card.
• The pass still works at your manufacturer until it runs out. The app deletes its copy but cannot cancel it at the manufacturer; nothing in the app holds it any more, so nothing can use it.
• Delete all my data is in Settings, under Your data. It deletes everything the app holds for you: your vehicles and their sign-ins, every trip, what the app learned, your places, your logs and your settings, on the server and on that phone. It asks twice and cannot be undone. You can still sign in afterwards.
• Deleting is immediate and permanent. The moment you delete, it is gone from the app. Nothing in the app can bring it back, whether you add the same vehicle again or sign in again.
• The only trace is on the server, and it isn't ours. The service that hosts our database automatically keeps rolling snapshots of the entire database for 30 days, so the whole service could be rewound after a disaster. A snapshot can't be searched, and one person's data can't be pulled out of it; the only thing it can do is rewind everything, for everyone. After 30 days it is erased automatically.