Advice about Android battery life usually arrives as a list of things to turn off, which is backwards. You do not need to dim the screen and kill animations on a phone that was fine last month. You need to find out what changed, and Android will tell you if you ask it in the right place.
The paths below are the ones Google documents. Phone makers rename these menus more than Google does, so the section at the end covers the common variations.
First: get the list of what actually used the battery
Open the Settings app, tap Battery, then Battery usage, then View by apps. Google documents this path in its page on getting the most life from an Android battery.
What you are looking for is an app near the top that you did not use much. An app you had open for two hours should be near the top: that is not a problem, that is arithmetic. An app you never opened sitting above your browser is the one worth chasing.
There is a second way in that lists every app at once: Settings, then Apps, then App battery usage.
Second: change what that one app is allowed to do in the background
Tap the app in that list and look for Allow background usage. Google documents three settings, and the differences matter more than the names suggest.
Unrestricted removes limits on how the app uses the battery in the background. Optimized is what Google recommends for most apps, and lets the system decide when the app runs. Restricted limits background battery use, and Google warns that some apps might not work as expected and some notifications might be delayed.
Restricted is the one to use on an app you want installed but do not need to hear from immediately. It is the wrong setting for a messaging app, an alarm, or anything you expect to wake the phone, because delayed notifications is exactly what it buys you.
Third: check whether the culprit is a setting rather than an app
If nothing in the list stands out, the drain is probably not an app at all. The usual suspects are a phone hunting for signal in a weak coverage area, which costs more battery than any app; a screen left at full brightness with adaptive brightness off; and a recently installed update that changed what syncs in the background.
Weak signal is worth testing deliberately. If the battery behaves differently in airplane mode with Wi-Fi on, the radio is the answer and no app setting will fix it.
If the menu is not where this says
Samsung, Xiaomi and others reorganise this area. On Samsung the equivalent lives under Settings, then Battery and device care, then Battery. If you cannot find Battery usage, pull down the notification shade, tap the battery icon, and you usually land on the same screen. The three background options are near universal even when the menu around them is not.
What this does not tell you
The list reports what used battery since the last full charge, which makes a single bad day look like a pattern and a slow degradation invisible. It also cannot distinguish an app that drains because it is badly written from one that drains because you asked it to sync constantly.
And none of it measures the battery itself. A three year old phone that lasts half as long as it did is usually reporting a worn cell, not a misbehaving app, and no setting on this page changes that.
One thing worth checking before blaming an app: whether the phone is still getting the updates that fix this kind of thing. When One UI 9 actually reached each Galaxy is the same question for Samsung owners, and the answer moved more than once.
Last updated October 4, 2026