The most common reasons your iPhone battery empties quickly
Fast battery drain usually comes from one of three sources: an app running constantly in the background, your screen brightness set too high, or your phone searching for a weak cellular signal. Less often, it's a hardware problem—a battery that has worn out after hundreds of charge cycles, or a component that's drawing power even when you're not using the phone. The fastest way to find out which one is happening is to check your battery usage settings, which shows you exactly which apps consumed power in the last 24 hours or the last 10 days.
Your iPhone stores this information automatically. Open Settings, tap Battery, then Battery Usage. You'll see a list of apps ranked by how much battery they used. If one app is using 40 percent or more of your battery while you barely use it, that's your culprit. If the percentages are spread evenly across many apps, or if the total is less than 80 percent, the problem is likely your screen brightness, location services, or a weak signal.
Key Takeaways
- Check Settings > Battery > Battery Usage to see which apps consumed the most power in the last 24 hours or 10 days.
- If one app is using more than 40 percent of your battery, turn off background app refresh for that app or uninstall it.
- Screen brightness, location services, and searching for a weak cellular signal are the most common causes when no single app stands out.
- If your iPhone is more than three years old and drains in a few hours even with light use, the battery itself may be worn out and need replacement.
- Turning off Wi-Fi and Bluetooth when you're not using them, and switching to Low Power Mode, can extend your battery life by several hours per day.
How to stop a single app from draining your battery
If the battery usage screen shows one app using far more power than the others, the app is either running constantly in the background or has a bug that makes it use power even when you're not looking at it. The first step is to turn off background app refresh for that app. Open Settings, tap General, then Background App Refresh. Find the app in the list and toggle it off. This stops the app from checking for new information, sending data, or running code when you're not actively using it.
If turning off background app refresh doesn't help, or if the app is one you don't use often, uninstall it. Open Settings, tap General, then iPhone Storage. Find the app, tap it, and choose Offload App (which keeps your data) or Delete App (which removes everything). Wait a few days and check your battery usage again. If the drain stops, the app was the problem. If it continues, the issue is elsewhere on your phone.
Reducing screen brightness and location services
Your screen is the single largest power consumer on your iPhone. If your battery usage screen shows no single app standing out, brightness is likely the cause. Open Settings, tap Display & Brightness, and turn on Auto-Brightness. This adjusts your screen to match the light around you, so it uses less power in dim rooms and only goes bright in sunlight. You can also manually lower the brightness slider to around 40 percent and see if that feels comfortable for your daily use.
Location services—the feature that lets apps know where you are—also drains battery quickly, especially if many apps are using it. Open Settings, tap Privacy & Security, then Location Services. You'll see a list of apps with location access. For each app, tap it and choose Never, While Using, or Always. Most apps only need location While Using, not Always. Maps and weather apps are the exceptions—they may need Always to work properly. Switching apps from Always to While Using can save several hours of battery life per day.
Checking for weak cellular signal and switching to Wi-Fi
When your iPhone can't find a strong cellular signal, it works harder to stay connected, which drains the battery faster. If you're in a building with thick walls, a basement, or an area far from cell towers, your phone is constantly searching for a signal and using extra power. The fastest fix is to connect to Wi-Fi instead. Open Settings, tap Wi-Fi, and select your network. Your phone will use Wi-Fi data instead of cellular data, which uses less power.
If you're in a place where the signal is weak and you can't use Wi-Fi, turn on Low Power Mode. Open Settings, tap Battery, and toggle on Low Power Mode. This reduces performance and background activity across the entire phone, extending your battery life by several hours. Your phone will feel slightly slower, but it will last much longer. You can turn it off as soon as you reach a place with better signal or a charger.
When the battery itself is wearing out
Every iPhone battery degrades over time. After 500 full charge cycles—roughly two to three years of normal use—a battery typically holds 80 percent of its original capacity. After three to four years, it may hold only 60 to 70 percent. If your iPhone is older than three years and drains from 100 percent to zero in a few hours even with light use and no single app standing out in the battery usage screen, the battery is likely worn out.
You can check your battery's health by opening Settings, tapping Battery, then Battery Health & Charging. Look at the number under Maximum Capacity. If it's below 80 percent, your battery has degraded. If it's below 60 percent, you'll notice a significant difference in how long your phone lasts. Apple and most repair shops can replace the battery for a fee that varies by iPhone model and location. A replacement battery typically costs between $50 and $100.
Turning off features you don't need
Several iPhone features run constantly and drain battery even when you're not using them. Bluetooth searches for nearby devices whenever it's on, even if you're not connected to anything. Wi-Fi scans for networks in the background. 5G uses more power than 4G LTE. If you don't need these features right now, turn them off. Open Settings, tap Bluetooth and toggle it off. Tap Wi-Fi and toggle it off. For 5G, open Settings, tap Cellular, then Cellular Data Options, then Voice & Data, and choose LTE instead of 5G Auto or 5G On.
You can also turn off notifications for apps that don't need them. Open Settings, tap Notifications, and go through each app. If an app sends notifications you don't read, tap it and choose Off under Allow Notifications. Fewer notifications means your phone's screen turns on less often, which saves battery. Similarly, turn off Hey Siri if you don't use voice commands. Open Settings, tap Siri & Search, and toggle off Listen for "Hey Siri".
What to do if nothing works
If you've checked battery usage, turned off background app refresh, lowered brightness, switched to Wi-Fi, and your battery still drains in a few hours, the problem may be a hardware issue beyond the battery. A component inside the phone could be drawing power, or the battery itself could be defective rather than straightforward worn out. The next step is to back up your phone and perform a factory reset. Open Settings, tap General, then Transfer or Reset, then Erase All Content and Settings. This erases everything and reinstalls the operating system fresh.
If the drain stops after a reset, a software bug was the cause and you can restore your data from the backup. If the drain continues after a reset, contact Apple Support or visit an Apple Store to have the hardware checked. A technician can run diagnostics to determine whether the battery is defective or whether another component is drawing power. At that point, repair or replacement may be necessary.
Frequently Asked Questions
Why does my battery drain faster in cold weather?
Cold temperatures slow down the chemical reactions inside a battery, making it deliver power more slowly and appear to drain faster. Your phone may also shut down at 20 percent battery in cold weather, even though the battery isn't actually empty. Move to a warmer place and let your phone warm up for 15 to 20 minutes. The battery will recover and show its true charge level.
Does closing apps in the app switcher save battery?
No. Closing apps does not save battery because apps that aren't running don't use power. In fact, closing an app and reopening it later uses more power than leaving it in memory, because your phone has to reload it from storage. Only turn off background app refresh for apps you don't need running in the background.
Should I keep my iPhone plugged in all the time to preserve the battery?
No. Leaving your phone plugged in constantly actually wears out the battery faster. Modern iPhones have optimized charging that slows down charging after 80 percent, but the battery still degrades slightly with each charge cycle. Charge your phone when it reaches 20 to 30 percent, and unplug it when it reaches 80 to 90 percent for the longest battery life.
Does using Low Power Mode damage my iPhone?
No. Low Power Mode is safe to use anytime. It reduces performance and background activity, but it doesn't harm the phone or the battery. You can leave it on permanently if you prefer longer battery life over maximum speed, though most people turn it on only when the battery is low.
Can I replace my iPhone battery myself?
It's technically possible, but not recommended. iPhone batteries are glued in place, and removing one requires special tools and skill. If you damage the battery or other components during removal, you could create a safety hazard or make the phone unusable. Apple and authorized repair shops have the proper equipment and training. The cost is usually $50 to $100 depending on your model.