The most common reasons your iPhone battery empties quickly
Fast battery drain usually comes from one of three places: 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 drawing power when it shouldn't.
The fastest way to find out which one is happening is to open Settings, tap Battery, then Battery Health & Charging. If the Maximum Capacity shows below 80 percent, your battery itself has degraded and won't hold a charge as long as it used to. If it's above 80 percent, the problem is almost certainly software — something your phone is doing, not something broken inside it.
Even if Maximum Capacity is low, you can still extend the time between charges by finding and stopping the apps or settings that drain fastest. The steps below work whether your battery is new or worn.
Key Takeaways
- Check Settings > Battery > Battery Health & Charging to see if your battery's maximum capacity has dropped below 80 percent, which means the battery itself is wearing out.
- If maximum capacity is above 80 percent, use Settings > Battery to see which apps used the most power in the last 24 hours or 10 days, then close or uninstall the top drainers.
- Screen brightness, location services, and background app refresh are the three settings that drain the most power after apps themselves.
- If your phone gets hot while draining fast, or if the battery percentage drops visibly while you watch, a hardware problem may be present and you should contact Apple Support.
How to see which apps are using the most battery
Open Settings and go to Battery. You will see a list of apps with a percentage next to each one, showing how much of your battery that app used. The list shows the last 24 hours by default, but you can tap "Last 10 Days" at the top to see a longer pattern.
The app at the top of the list used the most power. If it's an app you use constantly — like Maps while driving, or a video app while streaming — that's normal. If it's an app you barely use, or one that shouldn't be running at all, that's your culprit. Tap the app name to see whether it was running in the background or only when you were actively using it. If it says "Background Activity", the app is draining power even when you're not looking at it.
For apps that show heavy background activity, you have two choices: uninstall the app, or turn off background app refresh for just that app. Go to Settings > General > Background App Refresh, find the app, and toggle it off. The app will still work when you open it, but it won't run in the background.
Screen brightness and display settings that drain battery fastest
Your screen is usually the single biggest power consumer on your phone. If you keep brightness at maximum, or if you have auto-brightness turned off, you're draining the battery much faster than necessary.
Go to Settings > Display & Brightness. Turn on "Auto-Brightness" — this lets your phone adjust brightness based on the light around you, so you're not running at full brightness indoors. If you want to keep auto-brightness off, manually lower your brightness by swiping up from the bottom of the screen to open Control Center and dragging the brightness slider down.
Also check Settings > Display & Brightness > Auto-Lock and set it to 1 Minute or 2 Minutes. This makes your screen turn off faster when you're not using it, which saves power. If you have an iPhone with an always-on display (iPhone 14 Pro and newer), go to Settings > Lock Screen and toggle off "Always On" if battery life matters more to you than seeing the time and notifications without waking the phone.
Location services and background activity draining power
Apps that use your GPS location drain battery constantly because GPS is power-hungry. You don't need location services on all the time for every app.
Go to Settings > Privacy & Security > Location Services. You'll see a list of apps with a small arrow next to each one. A purple arrow means the app used location recently; a gray arrow means it's set to use location but hasn't used it yet. Tap each app and choose "Never" for apps that don't need your location, or "While Using" for apps that only need it when you're actively using them. Maps, for example, should be "While Using". A weather app might be "Never" if you don't need live location updates.
Also check Settings > Privacy & Security > Location Services and scroll to the bottom. Turn off "System Services" for anything you don't use — Significant Locations, Improve Maps, and similar features all use GPS in the background.
Cellular signal problems that cause constant battery drain
If your phone is in an area with weak cellular signal, it works harder to stay connected and drains the battery faster. You'll notice this most in basements, rural areas, or buildings with thick walls. Your phone is constantly searching for a stronger signal, which uses power.
If you're in a weak signal area and don't need cellular data, turn on Airplane Mode by swiping down from the top-right corner (or up from the bottom on older iPhones) and tapping the airplane icon. This stops your phone from searching for signal. If you need to stay connected, switch to Wi-Fi instead — Wi-Fi uses less power than cellular when the signal is strong.
You can also check which network your phone is using. Go to Settings > Cellular > Cellular Data Options > Voice & Data. If your phone is set to 5G and you're in a weak 5G area, it may drain faster than LTE. You can switch to LTE-only by choosing "LTE" from this menu, though this will slow your data speeds.
When battery drain means a hardware problem
If your phone gets noticeably hot while the battery drains, or if the percentage drops visibly while you're watching it (like 1 percent every few seconds), a hardware component may be failing. This is rare, but it happens.
The most common hardware cause is a battery that has reached the end of its lifespan. iPhones are designed to hold 80 percent of their original capacity after 500 full charge cycles. If you've had your phone for three or more years and use it heavily, the battery may straightforward be worn out. If Maximum Capacity in Settings > Battery > Battery Health & Charging is below 50 percent, Apple will usually replace the battery for a fee (around $69 for most models, though this varies by location and model).
Less commonly, a component on the logic board is drawing power abnormally. If you've dropped your phone recently, or if it got wet, this is more likely. Contact Apple Support or visit an Apple Store to have them run diagnostics. They can tell you whether the problem is the battery or something else.
Low Power Mode and other settings that extend battery life
Once you've found and fixed the main drain, you can extend battery life further with Low Power Mode. Swipe down from the top-right corner to open Control Center and tap the battery icon. This reduces performance and background activity, but it can add several hours to your battery life.
You can also set your phone to turn on Low Power Mode automatically. Go to Settings > Battery and toggle on "Low Power Mode" to turn it on now, or tap "Low Power Mode" to set it to turn on automatically when your battery reaches 20 percent.
Other settings that help: turn off notifications you don't need (Settings > Notifications), disable Wi-Fi and Bluetooth when you're not using them, and close apps running in the background by swiping up from the bottom of the screen and swiping up on the app cards.
Frequently Asked Questions
Why does my battery drain faster in cold weather?
Cold temperatures reduce how much power a lithium battery can deliver temporarily. Your phone may show a lower percentage or shut down even though the battery isn't actually damaged. Warm it up indoors and the percentage will usually return to normal. If it doesn't, the battery may have a hardware problem.
Does closing apps in the background actually save battery?
Closing apps by swiping them away from the app switcher helps only if the app was actively running. Most of the time, iOS suspends apps automatically, so closing them does little. The real drain comes from apps with background app refresh turned on. Turning that off for specific apps saves more battery than closing them manually.
Should I turn off Wi-Fi and Bluetooth to save battery?
Only if you're not using them. Leaving them on while you're not connected to anything does drain some power, but the drain is small compared to screen brightness or location services. If you use Wi-Fi regularly, leaving it on actually saves battery compared to using cellular data.
Can I replace my iPhone battery myself?
Apple does not sell batteries to consumers for self-replacement on most models. You can take your phone to an Apple Store or an authorized repair shop, where they can replace it. The cost varies by model and location, usually between $50 and $100. Some third-party repair shops charge less, but Apple's warranty covers battery replacement if the capacity has dropped below 80 percent within the first year.
What's the difference between Maximum Capacity and Battery Health?
Maximum Capacity shows what percentage of the original charge your battery can now hold — 100 percent means it's new, 80 percent means it holds 80 percent as much charge as it did when new. Battery Health is Apple's overall assessment of whether the battery is performing normally. Both appear in Settings > Battery > Battery Health & Charging.