Batbrief

Android can produce a bug report: a complete record of what the phone did, minute by minute, including every time the battery level moved and why. It is the file developers ask for when something is wrong. Everything needed to explain a bad night is already in it.

The tools that read it show you charts. Batbrief gives you a verdict.

What it tells you

• How much went while you weren't using itThe one number that matters. Drain with the screen off is what settings can fix; drain with it on is a matter of habits. They are separate problems.
• Whether the cause is permanent or scheduledIdle drain that is the same by day and by night has a cause that runs around the clock. Much worse at night means something is scheduled. Much worse by day means using the phone sets it off.
• Whether the phone actually sleptAnd if it did not, whether an app held it awake or the hardware kept waking it — which decides whether restricting an app can help at all.
• What was downloaded while you sleptApp updaters are the usual answer, and they are usually a switch away from stopping.
• Whether the modem spent the night hunting for signalA radio with no network to find is the most expensive thing a phone can do, and it looks like nothing at all in the battery screen.
• What the report can't tell youA truncated history, a missing coulomb counter, a power model the device itself does not agree with. Stated, not hidden.

Claim, proof, action

Every finding has three parts, and it is not shown unless it has all three:

• the claim — “the phone did not sleep for 62% of the night”;
• the proof — CPU awake 4h51m out of 7h49m, 22,150 wakeups from the Wi-Fi chip;
• the action — and a button that opens the exact system screen that changes it.

Without the proof it is a horoscope. Without the action it is a chart.

Measured, not modelled

Android’s own per-app battery estimates come from a model, and on many phones the model’s components add up to a fraction of what the battery actually lost. Batbrief reads the coulomb counter instead — the hardware register that says how many milliamp-hours are left — so the headline figures are measured rather than guessed.

Where a number is an estimate it says so, and where the device’s model disagrees with the charge actually lost, Batbrief tells you its per-app figures are not worth much on that phone rather than ranking your apps by them.

Privacy is the reason for half the design

A bug report is the most identifying file your phone can produce. It contains your Wi-Fi network names, your accounts, the text of your notifications and a complete list of your apps.

So Batbrief asks for no permissions at all — not even internet access. The file reaches it through the standard Android share sheet, it is unpacked into the app’s own private cache, analysed there, and deleted when you close it. There is no server, no account, and no analytics of any kind compiled into the app.

This is not a policy that could be changed quietly: an app with no internet permission cannot send anything anywhere. The Privacy Policy says the same thing at greater length.

How to feed it a report

1. In Settings → Developer options, tap Bug report and choose Full report. (No developer options? Settings → About phone → tap Build number seven times.)
2. Wait a couple of minutes. A notification arrives when it is ready.
3. Tap Share, and pick Batbrief.

From a computer, adb bugreport report.zip produces the same file. A plain adb shell dumpsys batterystats dump works too, with fewer per-app figures in it — and that one no other tool will read at all.

Get it

Batbrief requires Android 8.0 or later.

• Changelog — what changed in each release
• Source code
• Privacy Policy · Terms of Service