Fast battery drain usually comes from one of three places: a background app using power constantly, a hardware problem like a failing battery, or settings that keep your screen or radios active when you don't need them
Your iPhone's battery life depends on what's running in the background and how hard your screen is working. If your phone dies in a few hours instead of a full day, something is either using power at an unusual rate or your battery itself is degrading. The good news is that you can usually find the culprit without taking the phone apart.
Start by checking which apps are draining the most power. Open Settings, tap Battery, then Battery Usage. This screen shows you the percentage of battery each app has used in the last 24 hours or the last 10 days. If one app is using 30 or 40 percent of your battery while you barely use it, that's your problem. If the percentages look even across many apps, the issue is more likely a setting or the battery itself.
Key Takeaways
- Check which apps are draining battery by opening Settings > Battery > Battery Usage, and look for any single app using an unusually high percentage.
- Background app refresh, location services, and screen brightness can drain battery quickly even when you're not actively using your phone.
- If battery usage looks even across apps, your battery may be aging and losing capacity, which Apple can test with a battery health report.
- Turning off features you don't use—like Bluetooth, location, and push notifications—extends battery life without affecting core phone function.
- If your phone is more than three years old and battery health is below 80 percent, a battery replacement is usually the fastest solution.
Apps running in the background are the most common cause
Apps can use battery even when you're not looking at them. Background App Refresh lets apps check for new data—emails, messages, weather updates—without you opening them. This is convenient, but it drains battery constantly.
Go to Settings > General > Background App Refresh. You'll see a list of apps with toggles next to them. Turn off Background App Refresh for apps you don't need constant updates from. For example, you probably don't need a game refreshing in the background, but you might want it on for Mail or Messages. If you turn off Background App Refresh entirely, apps will only update when you open them.
Some apps also use battery because they're tracking your location constantly. Maps, weather apps, and fitness apps need location access to work, but other apps ask for it and then check your location even when closed. Go to Settings > Privacy > Location Services and review which apps have permission. For each app, tap it and choose Never, While Using, or Always. "While Using" means the app can only see your location when it's open, which saves battery.
Screen brightness and display settings drain battery faster than anything else
Your screen is the single biggest battery consumer on an iPhone. If brightness is set to maximum, your battery will drain noticeably faster. Auto-Brightness adjusts screen brightness based on the light around you, which saves battery because your screen doesn't stay at full brightness in dim rooms.
Go to Settings > Accessibility > Display & Text Size and turn on Auto-Brightness. You can also lower the maximum brightness manually by swiping down from the top-right corner of your screen and dragging the brightness slider left.
If your phone is an iPhone 12 or newer, you also have a ProMotion display that refreshes 120 times per second instead of the standard 60. This looks smoother but uses more battery. Go to Settings > Display & Brightness and look for 120 Hz or ProMotion. You can turn this off to save battery, though the screen will feel less smooth when scrolling.
Location services, Bluetooth, and notifications add up over time
Location Services keeps your phone's GPS and location radios active. Many apps request location permission and then check it regularly. Go to Settings > Privacy > Location Services and turn it off entirely if you don't need it, or go through the list and set apps to "While Using" instead of "Always".
Bluetooth is usually not a major drain, but if you have Bluetooth turned on and no device connected, your phone is searching for devices in the background. Go to Settings > Bluetooth and turn it off when you're not using wireless headphones or a car system.
Push Notifications wake your phone's screen and processor every time an app sends you a notification. Go to Settings > Notifications and turn off notifications for apps you don't need alerts from. You can also turn off Badge App Icon (the red number on app icons) and Sounds for apps that don't need them.
Check your battery health to see if the battery itself is failing
iPhones have a battery health report that shows how much capacity your battery has lost over time. Go to Settings > Battery > Battery Health & Charging. You'll see a percentage labeled Maximum Capacity. A new iPhone shows 100 percent. As the battery ages, this number drops.
If your Maximum Capacity is above 80 percent, your battery is still in good shape and fast drain is likely caused by an app or a setting. If it's between 70 and 80 percent, your battery is aging but still usable. If it's below 70 percent, your battery has lost a significant amount of capacity and replacing it will likely solve the problem.
You'll also see a section called Charging Optimization. If it says "Battery health is significantly degraded," Apple is already limiting how much power your battery can deliver to protect it. This can make your phone feel slower and drain faster under heavy use. A battery replacement is the solution.
Overheating can cause fast battery drain and damage the battery long-term
If your iPhone feels hot to the touch, it's working harder than it should be, which drains battery faster. Overheating can happen because of a demanding app, too much sunlight, or a hardware problem.
If your phone is hot, close all open apps by swiping up from the bottom of the screen (or swiping down from the top-right on newer iPhones with Face ID) and holding on each app, then swiping up. Move your phone to a cooler place, away from direct sunlight. If it stays hot even when you're not using it, a background app or a hardware issue may be the cause. Check your Battery Usage screen again to see if one app is using an unusual amount of power.
Repeated overheating can permanently damage your battery, so if your phone regularly gets hot, have it checked by Apple or a certified repair shop. They can run diagnostics to see if a hardware component is failing.
When to take your iPhone to Apple or a repair shop
If you've turned off Background App Refresh, lowered brightness, disabled location services, and your battery still drains in a few hours, the problem is likely the battery itself or a hardware issue you can't fix with settings.
Apple can run a battery diagnostic at any Apple Store or Apple Authorized Service Provider. They'll tell you the exact health of your battery and whether it needs replacement. Battery replacement costs vary by iPhone model and whether you have AppleCare+, but it's usually between $50 and $100 without coverage.
If your phone is still under warranty or you have AppleCare+, the replacement may be free or discounted. If your phone is very old and the repair cost is close to the price of a new phone, you may want to consider replacing the phone instead.
Frequently Asked Questions
Does closing apps in the background actually save battery?
Closing apps manually doesn't save much battery because iOS suspends apps automatically when you're not using them. The real battery drain comes from apps that have Background App Refresh turned on or apps that request location constantly. Turning off those permissions saves more battery than closing apps.
Will turning off Wi-Fi and using cellular data instead save battery?
No—Wi-Fi uses less battery than cellular data. Keep Wi-Fi on when you're home or at work. Turning off Wi-Fi and using only cellular actually drains battery faster because your phone has to work harder to maintain a cellular connection.
Is it bad to leave my iPhone plugged in overnight?
Modern iPhones have charging optimization that slows charging once the battery reaches 80 percent, so leaving your phone plugged in overnight won't damage the battery. However, keeping your battery at 100 percent all the time does cause very slow degradation over years. If you want to maximize battery lifespan, try to keep it between 20 and 80 percent most of the time.
Can a software update fix fast battery drain?
Sometimes. If a buggy app or iOS version is causing the drain, updating to the latest iOS version may help. Go to Settings > General > Software Update to check for updates. However, if your battery health is already low, a software update won't restore capacity.
Why does my battery drain faster in cold weather?
Cold temperatures slow down the chemical reactions inside your battery, making it deliver power less efficiently. Your battery may show a lower charge percentage in the cold, but it usually recovers when the phone warms up. If your phone shuts down in cold weather even though the battery shows 20 percent, this is normal and not permanent damage.