Xiaomi
Check Battery Usage Stats per App auf Xiaomi
Battery drain complaints usually come down to one thing: not knowing which app or system function is actually responsible. MIUI tracks this in the background and lets you view it broken down by percentage, covering things like the Android system itself, standby time, and active screen use.
To check it, go to Settings ➔ Battery & performance ➔ Choose an app. This opens a list ranking apps and system functions by how much battery they have consumed since the last full charge or reset.
What the numbers actually mean
A high percentage next to the screen usually means you have the brightness set too high or the screen timeout set too long. A high standby percentage on the other hand can point to a background app waking the device repeatedly, even when you're not using it.
If one specific app shows unusually high usage compared to how often you actually open it, that app is likely running background tasks it does not need. This is the point where restricting its background activity or checking its permissions makes more sense than a general battery saver mode.