Your data

Where sessions live

Every session is two things on your phone: a raw log file — the samples exactly as captured, stored unconverted — and database rows derived from it for display. The raw log is the record; the database is a projection of it, and can be rebuilt from the logs at any time.

Keeping, and not keeping

• Retention — keep history forever (the default), or one year, or six months; older sessions are removed at launch.
• Delete one session — removes its raw log and its database entries, after a confirmation. It cannot be undone.
• Delete everything — lives in a labeled danger zone and makes you confirm you understand. Uninstalling the app also removes all of its data.
• Watch retention — once a synced watch session has reached the phone, it stays on the watch for one more week, then is removed there; the phone's copy is the archive. An unsynced session is never removed — it's the only copy that exists.

Getting data out

Any session exports as CSV, or as its raw log, to a location you pick. There is no lock-in to a format you can't read: the CSV carries the time, watts, level and temperature the app's own table shows, plus the raw readings behind them — voltage, current, charge counter, thermal state, screen state and hinge angle.

Getting data in

The Wear OS build records the watch's charging on the watch, and syncs it to the phone over Bluetooth. The first time, open Settings → Devices → Receive from watch on the phone and tap Sync now on the watch. That tap is the consent: the phone shows a receipt naming the watch, and from then on sync takes no taps — dock the watch and its sessions arrive by themselves. Off the charger the watch stays quiet — with one exception: in the minute or so after you unplug it, the charge that just finished pushes once, so it is on the phone before you put the watch back on. Sync now is still there for the impatient. The phone only asks before trusting a device if a second unknown one turns up inside that same hand-opened window. A session log can also be imported as a file, from any ChargeLog device.

However a session arrives, it is identity-checked and reconciled against what the phone already holds: a log with no device identity, a malformed one, or a duplicate of a session already present never lands twice, and a file import tells you the reason it was refused. A synced session also stays that device's session — watch history is kept alongside the phone's, never blended into the phone's own charging portrait. A session history you can't trust is worse than a shorter one.

What leaves the phone

Nothing, on its own. ChargeLog needs no connection to record or analyze a charge, and it has no analytics, telemetry or crash-reporting code. It does ask, once during the tutorial and again in Settings, whether you would like your anonymized charging curves to join an open dataset: off unless you turn it on, with a preview showing exactly what would be sent — rounded curves only, never your tags or notes — published only as per-model aggregates, and only where at least 20 different anonymous ids stand behind a point (the ids are minted on the phone and change monthly, so that is a floor on ids rather than on phones), and withdrawable for as long as this phone still holds ChargeLog and its record of what it sent. Contributing is the one thing the phone app uses the network for, and the privacy policy says exactly what is sent and where; the watch app has no network permission at all. The dataset has a page of its own — the open dataset — that says what a contribution contains and where the dataset stands.