You unplug your phone at 100% in the morning, barely use it, and somehow the battery is already falling much faster than expected.
Sometimes the battery itself is ageing. Other times poor mobile signal, navigation, high screen brightness or a recent system update may be responsible. But an app doing more work in the background than expected is another common place to investigate.
Fortunately, both Android and iPhone include built-in battery-usage tools that can show which apps used power and whether much of that activity happened while you were not actively using them.
You usually do not need a third-party “battery cleaner” app. Start with the tools already built into your phone.
How to Check Battery Usage on Android
The exact menu names vary between Google Pixel, Samsung Galaxy, Xiaomi, OnePlus and other Android phones, so there is no single path that applies perfectly to every device.
On a recent Google Pixel, Google recommends opening:
Settings → Battery → Battery usage → View by apps
From there, you can select an app to review its battery behaviour and background-use settings. Google documents these steps in its official Pixel battery-drain guide. (Google Support)
What to Look For
Do not immediately blame whichever app appears first.
If you spent two hours watching YouTube, playing BGMI or scrolling Instagram, those apps should naturally account for a significant portion of your battery use.
Instead, look for apps that appear unusually active relative to how much you actually used them.
For example:
an app you barely opened but which shows significant background activity
a newly updated app that suddenly uses much more battery
an app repeatedly active while the screen was off
an unfamiliar app or utility consuming unexpected power
The useful comparison is not simply “which app used the most battery?”
It is:
“Does this battery usage make sense based on how I used the app?”
How to Check Battery Usage on a Samsung Galaxy
Samsung's current Galaxy software provides its own Device Care tools.
Samsung recommends going to:
Settings → Device care → Battery
From there, you can open the battery details to see usage by apps and features. Samsung also provides Background usage limits, where rarely used apps can be placed into Sleeping or Deep sleeping modes. Samsung explains these battery controls on its official India support page. (Samsung)
Samsung describes the two modes differently:
Sleeping apps may occasionally operate in the background, although notifications or updates can be delayed.
Deep sleeping apps generally do not run in the background and become active when you open them. (Samsung)
That can be useful for apps you use only occasionally.
Avoid putting messaging, banking, smartwatch, health-tracking or other apps into aggressive sleep modes if you depend on timely background notifications or syncing.
How to Check Battery Usage on iPhone
Apple has also made battery diagnostics increasingly detailed.
On a current iPhone, open:
Settings → Battery
Then tap View All Battery Usage to inspect recent battery consumption.
Apple's current documentation says the Battery screen can show usage data over the last eight days, including which apps consumed power and how much activity occurred on screen or in the background. Apple explains the current Battery screen in its official support guide. (Apple Support)
This is one place where older guides may now be outdated: you may still see instructions online referring to a “Last 10 Days” view, but Apple's current interface and documentation refer to an eight-day battery-usage history. (Apple Support)
Pay Attention to “Background Activity” on iPhone
Background activity is particularly useful when diagnosing unexpected drain.
Apple explains that background activity can include tasks such as playing music, using navigation, syncing photos and fetching mail while the app is not the main thing visible on screen. Apple's battery guide explains how to interpret background activity. (Apple Support)
That means background activity itself is not bad.
Spotify playing music with the screen off should use battery.
Google Maps providing navigation should use battery.
A photo service uploading hundreds of images after setup may temporarily use significant power.
The warning sign is background activity that does not match what you expected the app to be doing.
Red Flags Worth Investigating
There is no universal rule such as “any app above 10% is a battery drainer.”
Battery percentages depend on how long you used the phone and what you did with it.
Instead, look for patterns.
1. High Battery Use With Very Little Actual Use
If you barely opened an app but it accounts for a large share of your day's consumption, investigate it.
It may be syncing, repeatedly checking location, downloading content or experiencing a software bug.
2. Unusual Background Activity
An app spending long periods active in the background deserves attention when there is no obvious reason for it.
On iPhone, Apple specifically recommends checking background activity when diagnosing unexpectedly high app battery usage. Apple's battery-drain troubleshooting page provides examples of this behaviour. (Apple Support)
3. Your Phone Becomes Warm While Sitting Idle
Heat and power consumption are closely related, but a warm idle phone does not automatically mean a rogue app is responsible.
Background software updates, photo indexing, poor cellular reception, cloud syncing and other system processes can also create temporary heat and drain.
If the warmth continues for hours and battery usage points toward one particular app, however, that app becomes worth investigating.
4. Battery Drain Appears Immediately After an App Update
If battery life suddenly becomes worse shortly after one application updates, check whether that app has moved unusually high in the battery statistics.
A later app update may fix the problem.
How to Restrict a Battery-Draining App on Android
On recent Pixel phones, Google recommends leaving most applications on the default Optimized battery setting.
If a particular app is causing trouble, you can open it from the Battery Usage screen and review Allow background usage. Google recommends Optimized mode for most apps in its Pixel support documentation. (Google Support)
Be cautious with aggressive restrictions.
Restricting background execution can interfere with:
message notifications
fitness tracking
smartwatch syncing
cloud backups
email updates
location-based functions
Battery saving is useful only if the app still works the way you need it to.
How to Reduce Background Activity on iPhone
On iPhone, go to:
Settings → General → Background App Refresh
You can control whether applications are allowed to refresh content when you are not actively using them. Apple documents Background App Refresh in its official iPhone support guide. (Apple Support)
You do not necessarily need to disable it globally.
A better approach is often to turn it off for apps that do not need regular background updates.
For example, a rarely used shopping app probably does not need the same background access as a messaging or navigation app.
Update the Problem App Before Deleting It
If one app suddenly begins consuming excessive battery, check for an update before uninstalling it.
On iPhone, Apple allows you to manually check App Store updates from your account page, and apps normally update automatically unless that setting has been disabled. Apple explains manual app updates here. (Apple Support)
Android users can do the same through Google Play.
If the problem appeared after an update, a later bug-fix release may resolve it.
When Uninstalling Makes Sense
If a non-essential app continues causing abnormal background drain after updating and restricting it, uninstalling it can be the simplest test.
Use the phone normally for a day or two afterward.
If battery life improves dramatically, you have a strong indication that the app was contributing to the problem.
You can then reinstall it, wait for a later version or use an alternative.
Don't Forget Battery Health
Apps are not always responsible.
Rechargeable batteries lose capacity as they chemically age.
On current iPhones, Apple says you can check battery condition under:
Settings → Battery → Battery Health
for iPhone 15 and newer, while older supported models may show Battery Health & Charging instead. Apple explains the current battery-health menus in its support guide. (Apple Support)
Samsung users can also run a battery status test through:
Samsung Members → Support → Phone diagnostics
Samsung documents that diagnostic tool on its official Galaxy battery-status support page. (Samsung)
If an older phone shows poor battery health, restricting apps will only help so much. A battery replacement may produce a much bigger improvement.
SpecFront Take
The most useful battery statistic is not simply which app appears at the top of the list.
Context matters.
A game consuming 25% of your battery after an hour of gaming may be completely normal.
A flashlight app using significant power in the background when you did not open it is much more suspicious.
Start with the phone's built-in battery screen, compare battery use with actual app use, and investigate unusual background activity rather than chasing the highest percentage alone.
For Android users, keep most apps on normal optimized settings and restrict only the genuine offenders. Google recommends the Optimized setting for most Pixel apps, while Samsung provides Sleeping and Deep sleeping controls for rarely used apps. (Google Support)
On iPhone, Battery Usage and Background App Refresh give you similar visibility and control. (Apple Support)
If battery drain continues even after your app usage looks normal, the next things to investigate are battery health, mobile signal, display settings and recent system updates rather than assuming another app must be responsible.