Best Battery Saver App for Android Is the One in Settings

Google’s own documentation for developers says a third-party app cannot improve the power use of an Android device, and Android already limits what apps do in the background. So most people do not need a battery saver app. What an app can do is measure, and for that we would install AccuBattery.

When the phone does not last the day

Turn on Battery Saver earlier, check Battery usage and restrict the app at the top. None of it needs an app.

Open Settings, tap Battery, then Battery Saver. Google’s help page says that while it is on, the phone switches to Dark theme and limits or turns off background activity, so some apps and features may be delayed. On a Pixel you can have it come on at a battery level you choose. Apps then refresh only when you open them, and location services stop when the screen is off. Pixel 3 and later add Extreme Battery Saver, which pauses most apps.

Under Settings, Battery, Battery usage, tap View by apps to see what has used the charge. Tap an app, then Allow background usage. Google recommends keeping every app on Optimized. For some apps you can go further and stop background use altogether, which is the fix for a single app that keeps draining the battery. On a Galaxy, open Settings, Battery and tap View details.

Adaptive Battery should stay on. It learns which apps you use and lets the ones you rarely open run less while you are not using them. It is on by default, Google’s advice is to leave it on, and Google notes that after you set up a phone it can take a few weeks to reach full effect. On a Pixel the switch is under Settings, Battery, Battery Saver, Adaptive Battery.

Samsung’s equivalent of Battery Saver is Power saving, under Settings, Battery. Samsung warns that background apps may not update or send notifications while it is on. The same Battery menu has Background usage limits, where the phone can put unused apps to sleep automatically. An app you add to Deep sleeping apps never runs in the background and only works when you open it. Samsung’s battery page lists the rest, including a Battery protection setting that can stop charging before 100% to slow the battery’s ageing.

Google’s battery help page also lists the settings that use less power:

• Let the screen turn off sooner.
• Lower the screen brightness, or let it adjust automatically.
• Turn on Dark theme.
• Turn off keyboard sounds and vibration.
• Restrict apps with high battery use.
• Delete accounts you no longer use.

The same page says heat drains a battery faster and can damage it, and that you should use the charger that came with the phone. The screen settings have their own page: screen dimmer apps for Android.

Why a cleaner or a booster cannot help

Android has had two power-saving features built in since version 6.0. Its developer documentation calls them Doze and App Standby. Doze puts off background processor and network work when the phone has been lying unused, and App Standby holds back the network activity of apps you have not opened lately. Both apply to every app, with nothing for you to switch on.

Many older battery savers worked by closing other apps. Android 14 took that away: Google’s notes for developers say that since that version an app can only kill its own background processes. The same passage explains why. Android keeps recently used apps in the background on purpose and removes them itself when it needs the memory. Closing them early makes things worse, because starting an app from nothing takes more power than resuming it.

That page then says plainly that a third-party app cannot improve the memory, power or thermal behaviour of an Android device, and reminds developers of Google Play’s policy on misleading claims. So skip anything whose listing promises a faster phone or a longer charge from one tap, and anything sold as a cleaner, a booster or a cooler. It is promising something the maker of the system says cannot be done.

Greenify is a different case. It is on Google Play with no ads, and it does something specific: it puts chosen apps into hibernation, using an accessibility service on phones that are not rooted. Its own listing warns that a hibernated app loses its alarms and push messages. Adaptive Battery and Samsung’s sleeping apps now do a similar job inside the system, so we would pass on it.

Checking battery health

On a Pixel 8a or later, open Settings, Battery, Battery health. Google shows the status as Normal or Reduced, and Reduced means capacity has fallen below 80%. On the same phones the charge cycle count is under Settings, About phone, Battery information. Google says the Pixel 6a to Pixel 8 Pro do not show a health status.

On a Galaxy phone, open the Samsung Members app, tap Support, start Phone diagnostics and choose Battery status. On other phones, look in the battery settings or on the maker’s support site. If there is nothing, this is the one job where an app earns its place.

AccuBattery, from Digibites, sticks to measuring, which is why we would install it. Its listing says it measures the battery’s real capacity in mAh and shows how much wear each charging session adds. It also shows battery use per app, and a charge alarm reminds you to unplug. It is free with ads and in-app purchases, and the Pro upgrade removes the ads and keeps history older than a day.

Battery Guru: Battery Health, from Paget96, covers the same ground, also free with ads and in-app purchases. It compares capacity against the original design figure and adds charging current, temperature alarms, a charging history and a monitor for wakelocks, the mechanism apps use to keep a phone awake. Its listing carries a line more battery apps should have: it measures and displays, and does not claim to modify your battery, speed up charging or extend battery life.

Both work from your charging sessions, so the capacity figure is an estimate that builds up over time.

Tracking down the app that drains it

Android’s own Battery usage screen comes first. GSam Battery Monitor, from GSam Labs, goes deeper: it ranks what it calls app suckers and lets you sort them by processor use, sensor use and wakelocks. It also estimates time remaining from your past use. It is free with ads, with a separate paid Pro version. For something that drains the phone overnight, it and Battery Guru are the ones for wakelocks.

Comparing chargers with Ampere

Ampere, from Brain_trapp, shows the current going into or out of the battery, so you can plug in two chargers or two cables in turn and see which is faster. It is free with ads and in-app purchases. Its developer is frank about the limits. The listing says the readings are not exact science, are only good for comparing chargers on the same phone, and that some phones lack the chip the app needs.

DevCheck, BatteryBot and Battery HD

DevCheck Device & System Info, from flar2, is a hardware information app with a battery section. The listing calls it completely ad-free. The free version shows live temperature, voltage, current, health and capacity, and the paid Pro upgrade adds tracking of battery use with the screen on and off.

BatteryBot Battery Indicator, from Darshan Computing, LLC, is smaller: an open-source indicator that puts the exact percentage in the status bar with temperature, health and voltage, and asks for no special permissions. It is free with no ads and no purchases, and there is a separate paid Pro version.

Battery HD, from smallte.ch, turns the percentage into hours left for calls, music, video and browsing, with charge alerts and a usage chart. It is free with ads, and it too has a separate paid Pro version.