iPhone app · No account, no car token, no cloud

How much of the battery is really left?

Buying a used EV, or selling one, always comes down to that question, and nobody can answer it from the outside. BatCap works it out from something you already have in front of you at every charge: the level before, the level after, and the kilowatt hours that went in.

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How it works

Log it, read it, compare it

No OBD dongle, no manufacturer account. Three gestures you already make at every charging stop, and the answer comes out of them.

Log the charge

One big slider for the state of charge, a stepper for the kWh, a tap for AC or DC. It takes a few seconds and you can do it with cold hands at a charging column.

Read the trend, not the reading

A single charge swings with temperature, with how full the pack was and with how the display rounded. So the headline is the median of your last five estimates, and the chart shows all of them against the capacity the pack had when it was new.

On a fast charge, record the curve

Tap a button every few minutes and BatCap compares the shape against a reference curve for your model, corrected for the outside temperature. The verdict is qualitative: in the expected range, or clearly below it.

What you get

An answer for the moment of the sale

The listing says "battery like new". BatCap gives you something better than a sentence: a charging log with a trend, computed from the car's own numbers.

Estimated usable capacity

Every session yields an estimate of the kWh that really fit, compared with the capacity the pack had when it was new.

The trend as the headline

The big number is the median of the last five estimates. One odd value does not move the verdict, and the chart shows every point.

Fast-charging curve

The shape of your curve against your model's reference, corrected for temperature. In the expected range or clearly below it, with no invented numbers.

Any EV

Presets cover the common models, and it works with Tesla and any EV; anything else you add by hand with its net capacity.

Your car hands over no token.

The other apps in this corner want the login to your car and then hold a token that reads your location, your trips and your charges for as long as you leave it there. BatCap connects to no vehicle and to no server, because there is no server. Turn on airplane mode and every part of the app still works: that is the proof, not a marketing line.

No car token

No vehicle login, no manufacturer API, no service in between. The app only ever knows the figures you type or confirm.

Works in airplane mode

Logging, the maths, the chart and the curve comparison all work offline. The only things that need a connection are Apple purchases and the list of other Freshlab apps.

The photo stays on the iPhone

If you use the photo shortcut, the screen is read by the Apple Intelligence model on the device. Nothing is uploaded anywhere. If that photo carries coordinates in its data, the app offers them as the charging location in the form, where you can remove it before saving.

No account, no tracking

No sign-up, no email address, no password. No analytics, no ads, no tracking identifiers and no cloud sync.

Transparency

The photo prefills, you confirm

If your iPhone supports Apple Intelligence, you can photograph the charging screen and the on-device model fills the figures into the form for you. Every value it fills in is labelled as an AI suggestion until you confirm or change it, because a model reading a photo of a bright screen through a windscreen gets things wrong. Nothing is saved except through the form. On an iPhone without Apple Intelligence the camera button is simply not there and nothing else changes: typing the numbers in is the full app, not a fallback.

The maths is a different matter: the capacity estimate and the curve verdict are deterministic arithmetic, not model output. They are still estimates. The new-capacity figures and the reference curves come from public sources, they are not manufacturer specifications, and BatCap is not a measuring instrument: what it gives you is an indication and a direction over time, not a warranty statement and not a number to put in a contract. A brand new pack can read above 100 %, because the reference figures are conservative; the app says so rather than quietly capping it.

What it costs

Free, with no cap

Logging charges, the trend, the chart and the curve comparison are all free. No subscription, no paywall and no monthly limit.

Buy us a coffee

If the app helps you value a car, you can buy us a coffee, a tapa or a dinner from the settings screen. In return you get a supporter badge and an alternative app icon. It is voluntary and it unlocks no features.
No subscription

There is no monthly plan, no pro version and no feature hidden behind a payment. The three optional purchases are one-off tips and change nothing about what the app does.

Support

Something not working as expected?

Write to support@freshlab.es. We answer in English, German and Spanish, usually within one or two working days. Tell us the iPhone model, the iOS version, the vehicle and what happened, and we save ourselves a round of questions.

What do I need to run BatCap?

An iPhone with iOS 26. The photo shortcut additionally needs a device that supports Apple Intelligence, with Apple Intelligence switched on in settings; on an iPhone without it the camera button is simply not there and nothing else changes. Typing the numbers into the form is the full app, not a fallback.

Does BatCap connect to my car?

No. BatCap never asks for access to your car, holds no vehicle token and talks to no server, because there is no server. Turn on airplane mode and every part of the app still works. The only network traffic is purchases handled by Apple and one small list of the other Freshlab apps, and neither carries anything from your charging log.

How reliable is the estimate?

It is an estimate, and the app calls it that. A single charge swings with temperature, with how full the pack was and with how the display rounded; that is why the headline number is the median of your last five estimates and the curve verdict stays qualitative. The new-capacity figures and the reference curves are estimates collected from public sources, not manufacturer specifications, and BatCap is not a measuring instrument: it gives you an indication, not a warranty.

Does the photo of the screen leave the iPhone?

No. The photo is analysed by the Apple Intelligence model on the device and is used only to prefill the form. Every value it fills in is labelled as an AI suggestion until you confirm or change it, and nothing is saved except through the form. The photo is not uploaded anywhere.

What does buying you a coffee get me?

A supporter badge inside the app and an alternative icon for your home screen. Nothing else: it unlocks no features, it removes no ads because there are none, and it lifts no limit because there is none either. It is a voluntary way to support the work, and the app behaves exactly the same if you never do it.

How do I delete my data?

Swipe a session in the list to delete it. Deleting a vehicle removes its sessions with it, and deleting the app from the iPhone removes everything, because the data only ever lives in its local storage. If you have an iCloud or computer backup enabled, that copy is yours and is managed in iOS settings.

The buyer's question, answered with data

BatCap arrives on the App Store shortly. Until then you can read exactly what it does with your charging data, which is leave it on your iPhone.