The most common reasons your iPhone battery empties quickly
Fast battery drain usually comes from one of three sources: apps running in the background, screen brightness set too high, or a battery that has aged past its useful life. Most of the time, you can fix it yourself by checking your settings and closing apps you are not using. If your phone is more than three or four years old, the battery itself may have degraded enough that it no longer holds a full charge.
The easiest way to find out what is draining your battery is to open Settings, tap Battery, then Battery Health & Charging. This screen shows you the maximum capacity your battery can hold right now — if it says 80 percent or lower, the battery has degraded and replacing it will solve most of your drain problem. If it says 85 percent or higher, something else is using power faster than it should.
Key Takeaways
- Check your battery health in Settings > Battery > Battery Health & Charging; if it shows 80 percent or lower, the battery itself has worn out and needs replacement.
- Background app refresh and location services drain power even when you are not using an app — turn them off for apps you do not need constant updates from.
- Screen brightness above 40 percent uses more power than almost anything else on your phone; auto-brightness or a lower manual setting cuts drain significantly.
- Older iPhones with iOS versions several updates behind may drain faster because the operating system works harder on older hardware.
- If your battery health is above 85 percent but drain is still fast, restart your phone first — a software glitch is often the culprit.
How background app refresh drains your battery
Apps can refresh their content in the background even when you are not looking at them — checking email, loading new posts, updating location. Each refresh uses power. If you have dozens of apps with background refresh turned on, your battery empties even while your phone sits on a table.
To turn off background refresh for specific apps, go to Settings > General > Background App Refresh. You will see a list of every app on your phone. Toggle off the ones you do not need constant updates from — for example, you probably do not need a news app refreshing every hour, but you might want it on for email or messaging. Turning this off for five to ten apps can add two to four hours to your battery life.
Location services work the same way. Apps like maps, weather, and fitness trackers use GPS constantly if you let them. Go to Settings > Privacy & Security > Location Services and scroll through each app. Change apps from "Always" to "While Using" or "Never" unless you have a specific reason they need to know where you are all the time.
Screen brightness and display settings that drain power fastest
Your screen is the single biggest power consumer on your phone. If you keep brightness above 50 percent, it uses more battery than all your apps combined. The fastest fix is to turn on auto-brightness, which adjusts the screen to match the light around you.
Go to Settings > Display & Brightness and toggle on Auto-Brightness. If you prefer to set brightness manually, keep it between 30 and 40 percent for normal indoor use — you can always raise it temporarily if you are outside in sunlight. Also check Settings > Display & Brightness > Lock Screen and make sure "Always On" is turned off if you do not use it. An always-on lock screen display drains 5 to 10 percent of your battery per day on newer iPhones.
When your battery has physically worn out
iPhone batteries degrade over time. After about 500 full charge cycles — roughly one year of normal use — a battery starts to hold less charge. After two to three years, most batteries drop to 80 percent of their original capacity. After four years, they often fall to 70 percent or lower.
If Settings > Battery > Battery Health & Charging shows 79 percent or lower, your battery has degraded enough that replacing it will solve your drain problem. Apple offers battery replacement for a flat fee at any Apple Store or authorized repair shop — the cost varies by iPhone model but is usually between $50 and $100. Third-party repair shops often charge less, though Apple's warranty covers the replacement for one year.
Do not ignore a degraded battery hoping it will improve — it will not. A worn battery also becomes less stable and may shut your phone off suddenly even when it shows 20 percent charge remaining.
Software updates and iOS versions that affect battery life
If your iPhone is running an iOS version that is several updates old, the operating system may work harder on your hardware than it should, draining battery faster. Apple releases iOS updates roughly every month, and each one usually includes battery optimizations.
Check your iOS version by going to Settings > General > Software Update. If an update is available, connect your phone to power and Wi-Fi, then install it. Updating usually takes 15 to 30 minutes. After you update, your battery drain may improve within a day or two as the system optimizes itself to your phone.
If you are running the latest iOS and drain is still fast, restart your phone — hold the side button and either volume button until the power-off slider appears, then slide to power off. Wait 30 seconds and turn it back on. A restart clears temporary files and stops background processes that may be stuck, and it fixes battery drain about 30 percent of the time.
Apps that drain battery the fastest
Some apps are power hogs by design. Navigation apps like Google Maps or Waze use GPS constantly and drain 10 to 15 percent per hour. Video apps like YouTube or TikTok use your screen at full brightness and drain 8 to 12 percent per hour. Social media apps with autoplay video drain 5 to 8 percent per hour.
To see which apps are using the most battery, go to Settings > Battery and scroll down to see battery usage by app over the last 24 hours or the last 10 days. If one app is using more than 30 percent of your battery and you do not use it constantly, try closing it when you are done and turning off its background refresh. If an app consistently drains more than 40 percent even when you barely use it, the app itself may have a bug — check the App Store to see if an update is available, or uninstall and reinstall it.
Frequently Asked Questions
Does low power mode really save battery?
Yes. Low Power Mode reduces screen refresh rate, limits background activity, and slows down processing. It typically adds 20 to 30 percent more time before your phone dies. Turn it on in Settings > Battery when you are below 20 percent charge, or enable it automatically at 20 percent by going to Settings > Battery > Low Power Mode.
Why does my battery drain faster in cold weather?
Cold temperatures slow down the chemical reactions inside your battery, making it deliver power more slowly. Your phone may also shut off at 20 percent charge in cold weather because the battery cannot supply enough power at that moment. The battery is not damaged — it will work normally again when it warms up.
Can I stop iCloud syncing to save battery?
You can, but it usually does not save much. iCloud syncing uses very little power compared to screen brightness or background app refresh. If you want to turn it off anyway, go to Settings > [Your Name] > iCloud and toggle off the services you do not need, like Photos or Mail.
Does closing apps in the app switcher save battery?
No. Closing apps manually does not save battery because iOS suspends apps automatically when you switch away from them. Manually closing apps actually uses more battery because your phone has to reload them from scratch the next time you open them. Let iOS manage which apps stay in memory.
Should I turn off Wi-Fi and Bluetooth to save battery?
Turning them off saves a small amount — maybe 5 to 10 percent over a full day — but the difference is small enough that most people should not bother. If you are away from Wi-Fi and Bluetooth devices all day, turning them off is worth it. Otherwise, focus on screen brightness and background app refresh first.