The most common reasons your iPhone battery empties quickly

Fast battery drain usually comes from one of four sources: apps running in the background, screen brightness set too high, location services turned on for apps that don't need it, or an aging battery that no longer holds a full charge. Most of the time it's the first three, and you can fix them yourself in minutes. If your phone is more than three years old, the battery itself may be worn out and need replacement.

The easiest way to find what's draining your battery is to open Settings, tap Battery, then Battery Usage. This shows you which apps have used the most power in the last 24 hours or the last 10 days. If one app is using far more than the others, that's your culprit. If the drain is spread across many apps, the problem is usually your screen brightness or a setting that's running constantly in the background.

Key Takeaways

  • Check Settings > Battery > Battery Usage to see which apps are draining power fastest, then close or uninstall the heavy users.
  • Screen brightness is often the biggest drain; lowering it to 40 percent or turning on Auto-Brightness can add hours to your battery life.
  • Location services, background app refresh, and push notifications drain battery even when you're not using your phone; turn them off for apps that don't need them.
  • If your iPhone is three years old or older, the battery itself may be degraded; check Settings > Battery Health & Charging to see the maximum capacity.
  • Restarting your phone weekly and keeping iOS updated to the latest version often stops mysterious drain without any other changes.

How to check your battery health and maximum capacity

Your iPhone's battery degrades over time, and Apple lets you see exactly how much capacity it has lost. Go to Settings, tap Battery, then Battery Health & Charging. You'll see "Maximum Capacity" as a percentage — if it's below 80 percent, your battery is aging and won't hold a charge as long as it used to.

If maximum capacity is 80 percent or higher, your battery is still in good shape and the drain is coming from software or settings, not hardware. If it's below 80 percent and you're seeing fast drain, you have two choices: replace the battery through Apple or an authorized repair shop, or manage your usage more carefully until you're ready to upgrade the phone.

Screen brightness and auto-brightness settings

Your screen uses more power than anything else on your phone. If you keep brightness at 80 percent or higher all day, you'll drain the battery much faster than someone who keeps it at 40 percent. The quickest fix is to swipe down from the top-right corner (or up from the bottom on older models) to open Control Center, then drag the brightness slider down to around 40 percent.

For a permanent solution, turn on Auto-Brightness. Go to Settings, tap Display & Brightness, then toggle on Auto-Brightness. Your phone will then adjust the screen brightness based on the light around you — bright outdoors, dim indoors — without you having to change it manually. This alone can add two to four hours to your battery life on a typical day.

Background app refresh and location services

Apps can run in the background even when you're not using them, checking for new messages, updating maps, or tracking your location. Each one drains battery. Go to Settings, tap General, then Background App Refresh. You'll see a list of every app that's allowed to refresh in the background. Turn it off for apps that don't need it — for example, you probably don't need a game or a news app refreshing while you're not looking at it.

Location services are another major drain. Go to Settings, tap Privacy & Security, then Location Services. You'll see which apps have permission to use your location. Turn it off entirely for apps that don't need it, or change the setting to "While Using" instead of "Always" so the app only uses location when you're actively using it. Maps, weather, and find-my-friends apps need location; most others don't.

Push notifications and email fetch settings

Every time your phone gets a push notification, it wakes up the screen and uses power. If you have notifications turned on for 20 apps, your phone is waking up constantly. Go to Settings, tap Notifications, and turn off notifications for apps you don't need alerts from. You can still check those apps manually whenever you want — you just won't get a ping every time something happens.

Email is a special case. Go to Settings, tap Mail, then Accounts, then Fetch New Data. If it's set to "Push", your phone is constantly listening for new mail. Change it to "Every 30 minutes" or "Hourly" instead. You'll still get your mail, but your phone won't be working to receive it constantly. If you only check email a few times a day, set it to "Manually" and fetch it yourself when you open the Mail app.

Restart your phone and update iOS

A straightforward restart clears out processes that may be running unnecessarily in the background. Hold the power button until you see "Slide to Power Off", slide it, wait 10 seconds, then hold the power button again until you see the Apple logo. Do this once a week, especially if you've noticed drain getting worse over a few days.

Apple also releases iOS updates that often fix battery drain bugs. Go to Settings, tap General, then Software Update. If an update is available, plug your phone into power and install it. Updating usually takes 15 to 30 minutes, but it can solve drain problems that no setting change will fix.

When to replace your battery or phone

If your maximum capacity is below 80 percent and you've turned off background refresh, lowered brightness, and disabled location services but the battery still drains in a few hours, replacement is your best option. Apple charges between $69 and $99 to replace the battery, depending on your model. You can also go to an authorized repair shop, which may charge less.

If your phone is five years old or older, the battery is probably not the only aging part. The processor, storage, and other components wear down too. At that point, replacing the phone may be more practical than replacing just the battery. But if your phone is two to four years old and the battery is the only problem, replacement is usually worth it.

Frequently Asked Questions

Why does my battery drain faster in cold weather?

Cold temperatures slow down the chemical reactions inside the battery, so it can't deliver power as quickly. Your phone may also shut down at 20 percent battery in cold weather even though the battery isn't actually empty. Warm it up indoors and the battery will work normally again. This is temporary and doesn't mean the battery is damaged.

Does closing apps in the background actually save battery?

Closing apps manually does almost nothing. iOS is designed to pause apps automatically when you're not using them. The only time closing apps helps is if an app is actively running and draining power — which you'll see in Battery Usage. For most people, it's not worth the effort.

Will turning off WiFi and Bluetooth save battery?

Turning them off saves a small amount of power, but not as much as lowering screen brightness or turning off background app refresh. If you're in an area with no WiFi or Bluetooth devices nearby, turning them off can help. But if you use them regularly, the convenience is usually worth the small battery cost.

Is it bad to leave my iPhone plugged in overnight?

Modern iPhones have optimized battery charging built in. When you plug in overnight, the phone charges to 80 percent, then waits until you usually wake up to finish charging to 100 percent. This reduces wear on the battery. Leaving it plugged in is fine and won't damage the battery.

Can a software bug cause battery drain?

Yes. Sometimes a buggy app or an iOS update causes unexpected drain. If drain started suddenly after you installed an app or updated iOS, try uninstalling the app or restarting your phone. If the problem continues, check Battery Usage to see if a specific app is the culprit, then uninstall it or wait for an app update.