Where your iPhone battery drains fastest

Your iPhone battery drains fastest when the screen is on, when apps run in the background, and when your phone searches for a signal. The good news is that most of the drain you see is not inevitable — it comes from settings you can change right now without losing the phone's core functions. The screen alone can account for 30 to 40 percent of daily drain, which means controlling what it does is the single biggest lever you have.

Before you start changing settings, open Settings > Battery to see which apps have used the most power in the last 24 hours or the last 10 days. This tells you whether your problem is the screen itself, a specific app running constantly, or something else. If one app is using far more than the others, that app is your first target — either close it when you are not using it, or turn off its background refresh in Settings > General > Background App Refresh.

Key Takeaways

  • Lowering screen brightness and enabling Auto-Brightness in Settings > Display & Brightness cuts battery drain by 20 to 30 percent for most users.
  • Turning off Background App Refresh in Settings > General > Background App Refresh stops apps from checking for updates when you are not looking at them.
  • Enabling Low Power Mode in Settings > Battery and Device Management extends battery life by 1 to 3 hours by slowing performance slightly and disabling some features.
  • Turning off Location Services for apps that do not need it, and setting others to "While Using" instead of "Always", prevents constant GPS drain.
  • Disabling Bluetooth, Wi-Fi, and cellular data when you are not using them saves power, but turning on Airplane Mode is the fastest way to stop all wireless drain at once.

Reduce screen brightness and enable Auto-Brightness

The screen is the single largest power consumer on your iPhone. Lowering brightness to 30 to 40 percent is the fastest way to extend battery life, and most people find they adjust within a day. Open Settings > Display & Brightness and drag the brightness slider down. If you find yourself adjusting it constantly, turn on Auto-Brightness instead — it dims the screen in low light and brightens it in sunlight, which matches what you actually need to see.

If you use your phone mostly indoors, Auto-Brightness alone can add 2 to 4 hours to your battery life. The trade-off is that you lose direct control — the phone decides brightness for you. If that bothers you, set brightness to 40 percent manually and leave Auto-Brightness off. The difference between 40 and 100 percent brightness is roughly 15 to 20 percent of your total daily drain.

Turn off Background App Refresh

Apps refresh themselves in the background even when you are not looking at them — they check for new messages, read updates, and refresh content. This happens constantly and drains battery even when your screen is off. Open Settings > General > Background App Refresh and you will see a list of every app that is allowed to refresh. Turn it off entirely, or scroll down and turn it off for individual apps that do not need it.

Most people can turn off Background App Refresh for social media apps, news apps, and games without noticing a difference. Keep it on for Mail, Messages, and any app that needs to alert you to something urgent. If you turn it off for Mail, you will still receive messages — you just will not see them until you open the app. This change alone can add 1 to 2 hours to your battery life.

Enable Low Power Mode

Low Power Mode is a built-in setting that reduces performance and disables some features to stretch battery life. When you turn it on, your phone slows down slightly, stops refreshing apps in the background, reduces animation, and lowers screen brightness automatically. Open Settings > Battery and Device Management and tap Low Power Mode to turn it on. You can also swipe down from the top right of your screen, find the battery icon, and tap it to enable Low Power Mode from Control Center.

Low Power Mode extends battery life by 1 to 3 hours depending on how much you use your phone. The slowdown is usually not noticeable for everyday tasks like texting, email, and browsing. Games and video editing will feel sluggish, but those are not tasks most people do on battery power anyway. You can leave Low Power Mode on all day, or turn it on only when your battery drops below 20 percent.

Control Location Services and disable it for apps that do not need it

Location Services uses GPS, Bluetooth, and cellular data to figure out where you are. Apps like Maps and Weather need it, but many apps request location permission and then check your location constantly in the background. Open Settings > Privacy & Security > Location Services and you will see every app that has asked for location access. For each app, you have three choices: turn it off entirely, set it to "While Using" (location only when you are actively using the app), or set it to "Always" (location even when the app is closed).

Change any app that says "Always" to "While Using" unless you have a specific reason for it to track you in the background. Social media apps, shopping apps, and games almost never need "Always" access. Maps and Weather can stay on "While Using" or "Always" depending on whether you want them to send you location-based alerts. Turning off Location Services for even three or four apps can add 1 to 2 hours to your battery life.

Turn off Bluetooth, Wi-Fi, and cellular data when you do not need them

Bluetooth, Wi-Fi, and cellular radios all consume power, especially when they are searching for a signal. If you are in a place with weak signal, your phone works harder to stay connected, which drains the battery faster. The fastest way to stop all wireless drain at once is to turn on Airplane Mode — swipe down from the top right, tap the airplane icon, and your phone stops searching for signal entirely. You can also turn off individual radios: swipe down from the top right and tap the Bluetooth icon to turn it off, or go to Settings > Wi-Fi and tap the toggle to turn it off.

If you are sitting at home on Wi-Fi, turning off Bluetooth saves power if you are not using wireless headphones or a watch. If you are away from home and have weak signal, turning on Airplane Mode and then turning Wi-Fi back on (so you can use Wi-Fi calling) can extend battery life by 2 to 4 hours. The trade-off is that you will not receive calls or messages unless they come through Wi-Fi, so this is best for situations where you know you will not need to be reached.

Check for battery health and replace the battery if it is worn

Over time, iPhone batteries lose the ability to hold a charge. After two or three years of daily use, a battery that once lasted all day might last only 6 to 8 hours. You can check your battery health by opening Settings > Battery and Device Management > Battery Health & Charging. Look at the "Maximum Capacity" number — if it is below 80 percent, your battery is worn and is the reason your phone does not last as long as it used to.

If your battery health is below 80 percent, you have two choices: replace the battery through Apple (which costs money and takes a few days), or accept that your phone will not last as long and use the settings above to extend it as much as possible. Apple offers battery replacement at most Apple Stores and through mail-in service. If your phone is under warranty or covered by AppleCare+, the replacement may be free. If not, the cost varies by model but is usually between $50 and $100.

Frequently Asked Questions

Will turning off Background App Refresh stop me from getting notifications?

No. Notifications still arrive — you just will not see them until you open the app. For Mail and Messages, you will still get alerts on your lock screen and in Notification Center. The difference is that the app is not checking for new messages constantly in the background, which saves power.

Does Low Power Mode slow down my phone noticeably?

Most people do not notice the slowdown for everyday tasks like texting, email, and web browsing. Apps take a fraction of a second longer to open, and animations are slightly less smooth. Games and video editing feel sluggish, but those are not typical battery-draining activities. You can turn Low Power Mode off anytime if you need full speed.

What is the difference between turning off Location Services and setting it to "While Using"?

"While Using" means the app can see your location only when you have it open. "Always" means the app can see your location even when it is closed and running in the background. For most apps, "While Using" is enough, and it uses less battery because the app is not constantly checking your location when you are not looking at it.

Can I leave Low Power Mode on all the time?

Yes. Low Power Mode is designed to be left on indefinitely. The slowdown is minimal for most tasks, and you will get better battery life. Turn it off only if you need full performance for something specific, like gaming or video editing.

Why does my iPhone drain battery faster in cold weather?

Cold temperatures slow down the chemical reactions inside the battery, which makes it harder for the battery to deliver power. Your phone may also use more power to heat the battery back to normal operating temperature. This is temporary — the battery will work normally again once it warms up. If your phone shuts down in the cold, it is a sign the battery is worn and should be replaced.