Phone Battery Draining Fast? Causes and Fixes for iPhone, Samsung and Android

Step 1: find out what is using the battery

On iPhone, open Settings > Battery. Apple shows how much battery each app used, with notes such as Background Activity, Location, or No Cell Coverage and Low Signal. On Samsung and Pixel, open Settings > Battery and look at usage by app.

If one app sits at the top and you barely opened it, that is your answer. Restrict it, update it or remove it. If the screen itself is the biggest user, brightness is the fix.

Step 2: check the things people miss

• Weak signal. Apple says that in poor coverage the phone keeps searching for a better signal, which drains the battery, and that Airplane mode helps where there is no coverage. Basements, lifts and some rural areas do this.
• Mobile data instead of Wi-Fi. Apple says Wi-Fi uses less power than a cellular network for data, and Google's Pixel heat advice also suggests Wi-Fi instead of mobile data where possible.
• Hotspot. Google says to turn off tethering and hotspots when you are not using them, and Samsung lists long hotspot use as a cause of heat.
• Heat. Google says a battery drains much faster when the phone is hot, even if you are not using it, and that this kind of drain can damage the battery.
• A new phone, a reset or a big update. Phones work harder while they restore, index and update apps. Google says Adaptive Battery may take a few weeks to fully take effect after setup or a factory reset.
• Age. If the battery itself is worn, no setting will bring the hours back.

• Why is my phone heating up?
• Check your battery health

Settings that really save battery on iPhone

These come from Apple's own battery advice.

• Low Power Mode: Settings > Battery. iPhone offers it at 20% and again at 10%. Apple says it reduces brightness, optimises performance and minimises animations, and stops some background downloads.
• Brightness: dim the screen or keep Auto-Brightness on (Settings > Accessibility > Display & Text Size).
• Background App Refresh: Settings > General > Background App Refresh. Set it to Wi-Fi only or Off, or switch it off for single apps.
• Location: Settings > Privacy & Security > Location Services. Give location only to apps that need it.
• Notifications: apps that keep waking the screen cost battery. Turn off notifications you do not read.

Settings that really save battery on Samsung and Pixel

From Samsung's and Google's own battery pages.

• Samsung: Settings > Battery > Background usage limits > Put unused apps to sleep. Samsung says sleeping apps stop running in the background.
• Samsung: Power saving mode, and Device care > Optimise now to cut background activity.
• Samsung and Pixel: keep Adaptive brightness on.
• Pixel: keep Adaptive Battery and battery optimisation on. Google recommends leaving apps on Optimized.
• Pixel: Google also says fewer accounts on the phone can save battery, and suggests stopping Wi-Fi from turning on automatically near saved networks.

Closing apps will not save battery

Swiping every app away is the most common battery habit, and it does not help. Apple says closing all your apps does not affect your device's overall performance, and that you should close an app only when it is unresponsive. Recently used apps only use power when they are active or doing specific background tasks.

If a single app misbehaves, close that one. Leave the rest.

• More phone myths and facts

Battery drains while the phone is not in use

Some overnight drain is normal. Big drops usually mean background sync, location, a weak signal at your bedside, or a hot room. Check Settings > Battery for the hours while you slept. If Apple shows No Cell Coverage and Low Signal, Airplane mode at night will help, as long as you do not need calls. If the phone also feels warm with the screen off, read the heating guide below.

Why is my phone battery draining so fast all of a sudden?

Check Settings > Battery for one app using far more than usual. A recent update, a new setup, weak signal, a hotspot left on or heat are the other common causes. If none fit, check battery health.

Does closing apps save battery on iPhone or Android?

No. Apple says closing all your apps does not affect overall performance and you should only close an app that is unresponsive. On Android, the battery settings that put unused apps to sleep do the job better.

Does weak signal drain the battery?

Yes. Apple says the phone keeps searching for a better signal in poor coverage, which drains the battery, and recommends Airplane mode where there is no coverage.

Does Wi-Fi or mobile data use more battery?

Apple says Wi-Fi uses less power than a cellular network for data, so use Wi-Fi when you can.