The most common culprits behind fast iPhone battery drain
Your iPhone battery drains fast because of one or more of these things: apps running in the background, your screen brightness set too high, location services turned on for apps that don't need it, or your phone searching for a weak cellular signal. Less often, it's a hardware problem—a battery that has genuinely worn out, or a component inside drawing power when it shouldn't.
The first step is to check which apps are using the most power. Go to Settings > Battery > Battery Usage (or Battery Health & Charging on older models), and you'll see a list ranked by how much battery each app has consumed in the last 24 hours or last 10 days. If an app you barely use is near the top, that's your answer.
The second step is to look at your screen time. Your display is almost always the single biggest battery drain on an iPhone. If you're getting four hours of screen-on time instead of eight, the problem is usually there first.
Key Takeaways
- Check Settings > Battery > Battery Usage to see which apps are consuming the most power, and uninstall or restrict the ones you don't use regularly.
- Your screen brightness and screen-on time account for the majority of battery drain in most cases, so lowering brightness or enabling Auto-Brightness often makes the biggest difference.
- Location services, background app refresh, and push notifications drain battery even when you're not using your phone, and you can turn them off per-app in Settings.
- If your iPhone is more than three years old and drains from 100% to 0% in a few hours, the battery itself may have degraded and may need replacement.
How to check your battery health and age
Your iPhone tracks the health of its battery and will tell you if it's degraded. Go to Settings > Battery > Battery Health & Charging. You'll see a number called Maximum Capacity—this is what percentage of the battery's original charge it can still hold.
A new iPhone battery is at 100%. After about 500 full charge cycles (a full cycle means charging from 0% to 100%), it typically drops to around 80%. At 80% capacity, you'll notice your phone dies sooner than it used to, but this is normal aging. If your Maximum Capacity is below 80% and your phone is less than two years old, the battery may be defective and Apple will replace it.
You'll also see a section called Charging Health on newer models. If it says "Normal," your battery is fine. If it says "Degraded" or "Service Recommended," your battery is wearing out faster than expected and replacement will help.
Background app refresh and location services
Apps can drain your battery even when you're not looking at them. Two settings control this: Background App Refresh and Location Services.
Background App Refresh lets apps update their content in the background—so your email app can fetch new messages, or a weather app can refresh the forecast. You don't need this for every app. Go to Settings > General > Background App Refresh, and turn it off for apps you don't need to stay current. Keep it on for email, messaging, and maps if you use them, but turn it off for games, news apps, and social media.
Location Services lets apps know where you are. This is useful for maps and weather, but many apps ask for location permission and then use it constantly in the background. Go to Settings > Privacy & Security > Location Services, and for each app, tap it and change the setting from "Always" to "While Using" or "Never." Most apps don't need to know your location when they're closed.
Screen brightness and display settings
Your screen is the biggest battery drain on almost every iPhone. The brighter your display, the faster your battery empties. If you're keeping your brightness at 80% or higher all day, that alone can cut your battery life in half.
The easiest fix is to turn on Auto-Brightness. Go to Settings > Accessibility > Display & Text Size, and toggle on Auto-Brightness. Your phone will dim the screen in dim rooms and brighten it in sunlight, so you're never using more brightness than you need.
If you have an iPhone 12 or newer with a 120Hz display, you can also limit the refresh rate. Go to Settings > Accessibility > Display & Text Size > Motion, and turn on Limit Frame Rate. This drops your display from 120 frames per second to 60, which saves battery at the cost of slightly smoother scrolling.
Push notifications and constant connectivity
Every time an app sends you a notification, your phone wakes up, lights the screen, and uses power. If you have dozens of apps sending notifications, this adds up. Go to Settings > Notifications, and turn off notifications for apps you don't need alerts from. Keep them on for messages, email, and calendar, but disable them for games, shopping apps, and news.
Similarly, if your phone is in an area with a weak cellular signal, it works harder to stay connected. Your phone will drain faster in a basement, a rural area, or a building with poor reception. If you're in a place with weak signal and you don't need data, turn on Airplane Mode to stop your phone from constantly searching for a signal.
When to replace your battery or contact Apple
If you've turned off background refresh, lowered your brightness, and disabled notifications, and your phone still dies in a few hours, the battery itself is likely the problem. Check your Maximum Capacity again. If it's below 80% and your phone is still under warranty or AppleCare coverage, Apple will replace the battery at no cost. If you're out of warranty, battery replacement costs between $50 and $100 depending on your model.
You can also take your phone to an Apple Store or an authorized repair shop to have them run a diagnostic. They can tell you whether the battery is the culprit or whether something else inside the phone is drawing power. Do not attempt to replace the battery yourself—iPhones are sealed and opening one can damage the display or other components.
If your phone is more than four years old and the battery is at 50% capacity or lower, replacement is usually worth the cost because you'll get several more years of usable battery life.
Frequently Asked Questions
Does closing apps in the background actually save battery?
No, not really. Closing an app doesn't save much battery because iOS suspends apps automatically when you're not using them. The exception is if an app is actively running in the background (you can see this in Battery Usage). In that case, force-closing it and then turning off Background App Refresh for that app will help.
Does turning off WiFi and Bluetooth save battery?
Turning off WiFi saves a small amount of battery, but turning off Bluetooth saves almost nothing. The bigger win is turning off Location Services and Background App Refresh. If you're in an area with no WiFi and no cellular signal, then yes, turn off both to stop your phone from searching.
Why does my battery drain faster in cold weather?
Cold slows down the chemical reactions inside your battery, so it can't deliver power as quickly. Your phone may shut down at 20% battery in cold weather, even though the battery isn't actually dead. Warm it up indoors and the battery will work again. This is temporary and doesn't damage the battery.
Can I use a third-party battery replacement to save money?
You can, but Apple batteries are higher quality and come with a warranty. Third-party replacements are cheaper but may not last as long or hold as much charge. If you go to an unauthorized shop, you may lose water resistance or other features. Apple's price is worth it if you can afford it.
Does leaving my phone plugged in overnight damage the battery?
No. Modern iPhones stop charging at 100% and hold the charge without overcharging. However, keeping your battery at 100% all the time does cause it to age slightly faster. If you want to maximize battery lifespan, unplug when you reach 100%, but this is a minor effect and not worth losing convenience over.