Charge Bench: Charger Test

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About this app

Your watch says "charging". It does not say how fast, how hot, or whether the dock you paid extra for is doing anything the cable in the drawer wasn't already doing.

Charge Bench records the whole charge — level, current, voltage, battery temperature, and the watts it computes from them — from the moment the watch lands on the charger until it comes off. Then it tells you what happened.

WHAT ONE CHARGE LOOKS LIKE

Every session becomes three curves on the same time axis:

• Charge level, so you can see the shape of the climb and where it flattens
• Power in watts, so you can see the constant-current plateau and where the taper begins
• Battery temperature, so you can see what the speed cost you

Under them, the numbers that let you argue with a spec sheet: average and peak watts, peak temperature, how long the battery spent above 35°, milliamp-hours actually delivered, and percent gained per hour.

COMPARING CHARGERS IS THE POINT

Name each charger once — the bedside dock, the pad at the office, the cable that came in the box — and assign it to a session with one tap. The history then reads as a comparison instead of a log:

Samsung Duo Dock · +59% · 1h 0m · 0.9 W avg · 34.7° peak
Anker Wireless Pad · +60% · 1h 18m · 0.6 W avg · 38.9° peak

Same watch, same night, eighteen minutes and four degrees apart. That is the kind of thing you cannot find out by looking at the charging animation.

IT KNOWS WHEN A CHARGE IS REALLY OVER

A charge that stops at 85% is not always finished — battery-protection features pause deliberately, and the watch will sit there for an hour before resuming. Charge Bench treats a pause as a pause: it waits for three consecutive not-charging readings, a current that has genuinely tapered, and a stable plateau at the ceiling this watch actually reaches, before it calls a session complete. A sixty-second wrist-off is discarded rather than filed as a "benchmark".

BUILT FOR A CHARGING WATCH, WHICH IS A HARDER PROBLEM THAN IT SOUNDS

A watch processor sleeps deeply even on the charger, and a sleeping app measures nothing. The recorder holds a wake lock only while a session is running, samples on a schedule that is dense where the curve is interesting and sparse where it is not, and writes every reading to disk as it takes it — so a charge that is interrupted keeps everything it had measured up to that second.

YOUR DATA IS YOURS, AND IT STAYS ON THE WATCH

The app has no internet permission. Not "we promise not to" — it cannot. There is no account, no analytics, no crash reporting, no advertising, and no cloud backup. Every reading it takes comes from your own battery and stays in the app's private storage until you delete it or uninstall.

Want it off the watch? Diagnostics → Export all data writes one file you can copy off yourself.

OPTIONAL: LET IT START ON ITS OWN

The charge worth measuring is usually the overnight one, and you are asleep for it. If you allow auto-start, setting the watch on a charger begins a recording without you opening anything. It is one tap in Diagnostics, you are asked rather than told, and declining costs you nothing — every recording you start yourself works exactly the same.

REQUIREMENTS

Wear OS 3 or newer. Standalone: it runs entirely on the watch and needs no phone app.

ONE HONEST LIMITATION

Charging current comes from the watch's fuel gauge, and not every watch publishes it. On a watch that does, you get watts. On a watch that doesn't, the current and power charts stay flat at zero and you still get level, temperature, duration and rate. Diagnostics tells you which one you have after the first docked minute, so you find out in sixty seconds rather than after a week.

What’s new

The app icon now shows at startup on every launch, and the launcher icon has a visible amber background.