Energy and battery
Battery complaints rarely include timestamps or steps to reproduce, and it is hard to separate your app from others running at the same time. This module helps you turn a complaint into measurable data.
Two types of question
Section titled “Two types of question”“How much energy does this app use right now?” This is a live question. Capture a session and read the energy counter alongside CPU, GPU and network. See Performance monitoring.
“What drained the battery overnight?” This is a historical question. No live capture was running, so use usage history, which reads the records the device keeps on its own.
What the energy value means
Section titled “What the energy value means”The value is an impact estimate based on the hardware the app kept busy. It is not a milliamp-hour measurement. Use it to compare:
- This build against the previous build, for the same interaction
- Your app against a competitor performing the same task
- The same screen with a feature turned on and off
A single value on its own is not a conclusion.
Common causes of high energy use
Section titled “Common causes of high energy use”| Behavior | Why it costs energy |
|---|---|
| Location updates | Continuous GPS is one of the most expensive operations on a phone. Requesting precise location only while moving costs far less than always requesting it. |
| Keeping the screen on | The display is often the largest consumer. Disabling the idle timer costs more than most computation. |
| Background refresh | Inexpensive once, but costly when repeated every fifteen minutes. |
| Frequent network requests | The radio uses the most energy when it wakes up. Ten batched requests cost less than a hundred separate ones, even for the same amount of data. |
| Repeating timers | A timer that never stops prevents the CPU from entering low-power states. |
| Video and animation | Continuous GPU work, often with the display at full brightness. |
How to collect evidence
Section titled “How to collect evidence”- Charge the device to a known level, then unplug it.
- Capture a fixed interaction, for example five minutes on the screen in question.
- Repeat with the suspected cause removed.
- Compare the two energy traces, along with CPU, network and location activity.
- For overnight drain, check usage history the next day instead.
Attach both captures to the ticket. Two traces give a clear answer.
Compare with the device’s battery screen
Section titled “Compare with the device’s battery screen”On the device, Settings → Battery shows per-app usage for the last 24 hours or 10 days. It is less detailed, but it is what the user sees when reporting the problem, so check it as well.
KeyMob’s usage history covers a longer period and shows which hardware each app kept active.
Free and VIP features
Section titled “Free and VIP features”The data analysis module requires VIP. It covers battery and charging, apps and energy use, wireless, sensors and more. See pricing.