Allen
@ChargeLog

I built ChargeLog to answer one question: how long does my phone actually take to charge in its extreme charging mode? I wasn't keeping track, and nothing I tried would tell me without also watching everything else I did with the phone. So I measured it myself.

That became the app. Every plug-in is kept as a session you can reopen: the power curve, the kink where it drops out of fast charging, how hot it got and when.

My phone already tells me when it'll be full

It does. Plugged in, Android says "Full by 7:40 AM", and it's usually right. Unplugged, it tells you roughly how long is left. But the charging estimate only exists once the cable is in, so it can never tell you when to plug in. And neither estimate knows what you're about to do: 40% is fine on a Tuesday at home, and not fine at the start of a six-hour drive. Neither one speaks first.

ChargeLog isn't a better guess than Android's. It's a different question over a longer window: Android estimates the charge in front of it, ChargeLog keeps months of your sessions and can be asked about tomorrow morning. So instead of "you're at 40%" you get "top up your phone ~20 min to reach 11pm." And when it hasn't seen enough to put an honest number on it, it says so and still tells you to charge. It will withhold a figure before it invents one.

Three reminders

Each is off until you turn it on.

• Keep a floor. Tells you when you drop to a level you pick, while you're away from a charger.
• Charged by a time. "Be at 80% by 7am." It works out when you'd have to plug in, and tells you before that moment passes.
• Get me to a time. "Get me to 11pm." If the battery won't make it, you hear about it while you can still do something.

And on your wrist

The Wear OS app is a ChargeLog of its own. It records the watch's charging, keeps its own history, and runs the same three reminders on the watch's own battery. A watch that dies at four in the afternoon is a watch you stop trusting.

If Android is bridging your phone's notifications to the watch, its reminders show up there too. Every notification names the device it's about, so "Watch at 15%" and "Phone at 15%" are never mixed up on a wrist whose own battery is fine.

Health, and where the number came from

Battery health is a fraction, and the denominator is the part apps don't show you: the capacity your phone claimed when it was new. That figure is often wrong. ChargeLog names the source it used, lets you correct it, and hides health entirely when it doesn't know. If the arithmetic comes out above 100%, it tells you the reference is wrong rather than printing a number that can't be true.

It watches the battery, not you

No per-app breakdown, just the overall level, the same number in your status bar. No analytics, no telemetry, no crash reporting. ChargeLog is not in your phone's usage-access list, and it never will be. Check it yourself: Settings, then Special app access, then Usage access.

What your support pays for

• hosting and services
• more test phones, so the charging math is checked on more than a couple of devices
• my time, which is the largest line by far

The recording engine, the part that captures and stores sessions, is open source under GPL-3.0-only: github.com/AllenBW/chargelog-recorder. The analysis, the app, and the site are proprietary.

Has ChargeLog earned its place on your phone? If it has, a donation keeps it moving. Whatever you decide is genuinely fine.

chargelog.org