What drains your iPhone battery the fastest
Your iPhone battery dies quickly because of one or more of these things running in the background: apps refreshing data, location services tracking your position, the screen brightness set too high, or your phone searching for a weak cellular signal. The most common culprit is background app refresh, which lets apps update their content even when you are not using them. A single app left running in the background can drain 10 to 20 percent of your battery in a few hours.
Other heavy drains include streaming video or music, using GPS navigation, playing games, and keeping Bluetooth on when you are not actively using a wireless device. If your battery dies faster than it did a year ago, the battery itself may be aging—iPhone batteries lose capacity over time and eventually need replacement.
The easiest way to find out what is actually 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 is your answer.
Key Takeaways
- Background app refresh is the single most common reason iPhones drain battery fast—turning it off for apps you do not actively use can add hours to your battery life.
- Check Settings > Battery > Battery Usage to see exactly which apps are consuming the most power, then disable background refresh for the worst offenders.
- Screen brightness, location services, and Bluetooth drain battery even when you are not actively using them—lowering brightness and turning off location for apps that do not need it saves significant power.
- If your iPhone is more than three years old, the battery itself may be degraded and unable to hold a charge the way it once did, and replacement may be the only real fix.
Turn off background app refresh for specific apps
Background app refresh is the setting that lets apps update their content in the background, even when you have closed them. Mail, weather, news, and social media apps use this feature heavily. You do not have to turn it off entirely—you can disable it for individual apps that you do not need to update constantly.
Go to Settings > General > Background App Refresh. You will see a list of every app on your phone. Toggle off the switch next to any app that does not need to refresh in the background. Keep it on for apps like Mail or Messages if you want to see new messages without opening the app. Turn it off for games, news apps, and social media unless you specifically want them updating while you are not using them.
This single change often adds 2 to 4 hours to your battery life, depending on how many apps you disable.
Lower your screen brightness and use auto-brightness
Your screen is usually the single biggest battery drain on an iPhone. The brighter your display, the faster your battery empties. If you keep your brightness at maximum, you are losing 15 to 25 percent of your battery life compared to someone using medium brightness.
Open Settings > Display & Brightness and drag the brightness slider to the middle or lower. Better yet, turn on Auto-Brightness by toggling the switch at the bottom of that screen. Auto-Brightness adjusts your screen brightness based on the light around you, so you get a readable display without wasting power in dim rooms.
You can also enable Dark Mode (Settings > Display & Brightness > Dark) if your iPhone has an OLED screen (iPhone 12 and newer). Dark Mode uses less power on OLED displays because black pixels require no backlight. On older LCD screens, Dark Mode makes almost no difference to battery life.
Turn off location services for apps that do not need it
Location services use your phone's GPS chip, which is a significant battery drain. Many apps request location permission but do not actually need it constantly. A weather app needs your location once to show your local forecast. A social media app does not need to know where you are at all.
Go to Settings > Privacy & Security > Location Services. You will see every app that has requested location access. Tap each app and choose "Never" or "While Using" instead of "Always." "While Using" means the app can access your location only when you have it open. "Always" means it can track you in the background, which drains battery and uses data.
For most apps, "Never" or "While Using" is the right choice. Only apps like Maps or your fitness tracker genuinely need "Always" access.
Disable Bluetooth and Wi-Fi when you are not using them
Bluetooth and Wi-Fi both use power to search for and maintain connections. If you have Bluetooth on but are not actively using wireless headphones or a smartwatch, you are wasting battery. The same applies to Wi-Fi—if you are on cellular data, leaving Wi-Fi on while your phone searches for networks drains power.
Swipe down from the top-right corner of your screen to open Control Center. Tap the Bluetooth icon to turn it off, and tap the Wi-Fi icon to turn it off. Turn them back on only when you need them. If you use Bluetooth regularly, this is a smaller savings than background app refresh, but it still adds up.
You can also go to Settings > Bluetooth and Settings > Wi-Fi to turn these off permanently if you rarely use them. Some people leave Wi-Fi on at home and at work but turn it off when traveling—that is a reasonable middle ground.
Enable Low Power Mode to extend battery life when ready
Low Power Mode is a built-in setting that reduces power consumption across your entire phone. It slows down performance slightly, reduces animation effects, and limits background activity. Most people do not notice the slowdown, but the battery savings are real—typically 1 to 3 extra hours of use.
Swipe down from the top-right corner to open Control Center and tap the battery icon. Or go to Settings > Battery > Low Power Mode and toggle it on. Your battery percentage will turn yellow to remind you that Low Power Mode is active. You can leave it on all the time if you want, or turn it on only when your battery drops below 20 percent.
Low Power Mode is not a permanent fix for a battery that drains too fast, but it is a quick way to get through the day if you are away from a charger.
Check whether your battery is degraded
iPhone batteries degrade over time. After about 500 full charge cycles (roughly two to three years of normal use), an iPhone battery loses about 20 percent of its original capacity. After three to four years, the loss is often 30 to 40 percent. A degraded battery cannot hold as much charge, so it drains faster and dies sooner.
You can check your battery health by going to Settings > Battery > Battery Health & Charging. Look at the "Maximum Capacity" percentage. If it is 80 percent or higher, your battery is still in good shape. If it is below 80 percent, your battery is degraded and replacement will likely improve your battery life significantly.
If your battery health is below 80 percent and you have tried all the steps above, battery replacement is usually the best solution. Apple and authorized repair shops can replace your iPhone battery. The cost varies by model but is typically between $50 and $100. If your phone is still under warranty or AppleCare+, the replacement may be covered.
Frequently Asked Questions
Does closing apps in the background actually save battery?
No, closing apps by swiping them away does not save battery. iOS automatically manages app memory and suspends apps you are not using. Closing them manually and then reopening them later actually uses more power because your phone has to reload them from scratch. The real battery drain comes from background app refresh, not from having apps in memory.
Should I turn off 5G to save battery?
5G does use more power than 4G LTE, but the difference is usually small—typically 5 to 10 percent. If you are in an area with strong 5G coverage, the faster speeds mean you finish downloading or streaming sooner, which can actually save battery overall. If you are in a weak 5G area where your phone is constantly searching for signal, turning off 5G (Settings > Cellular > Cellular Data Options > Voice & Data) may help.
Does leaving my phone plugged in overnight damage the battery?
No. Modern iPhones have built-in charging optimization that stops charging at 100 percent and holds the battery at that level until you unplug. Leaving your phone plugged in overnight does not damage the battery. However, keeping your phone in a hot environment while charging does degrade the battery faster, so avoid leaving it in direct sunlight or in a hot car.
Why does my battery drain faster in cold weather?
Cold temperatures slow down the chemical reactions inside your battery, which temporarily reduces its ability to deliver power. Your iPhone may shut down or show a low battery warning even though the battery is not actually damaged. When you warm the phone back up, the battery will work normally again. Extreme cold can permanently damage a battery, so avoid leaving your phone outside in freezing temperatures for long periods.
Can I replace my iPhone battery myself?
You can, but it is not recommended unless you have experience with phone repair. Opening an iPhone requires special tools and can damage the screen, water sealing, or internal components if done incorrectly. Apple and authorized repair shops have the right tools and can replace your battery without risking other damage. The cost is usually worth the safety and warranty protection.