The most common battery drains on iPhone
Your iPhone battery drains fastest when apps run in the background, your screen brightness is high, location services are on for apps that don't need them, and your phone is searching for a weak cellular or Wi-Fi signal. These four things account for most of the battery loss people notice between charges.
Beyond those, a phone that is too hot or too cold will drain faster because the battery works less efficiently. A battery that has gone through many charge cycles (typically 500 or more) also holds less charge than a new one. And if you have recently updated to a new iOS version, your phone may be indexing files in the background for a day or two, which temporarily increases drain.
The easiest way to know what is actually draining your battery is to check the Battery Health section in Settings, which shows you which apps used the most power in the last 24 hours or the last 10 days. This is more useful than guessing.
Key Takeaways
- Open Settings > Battery > Battery Health & Charging to see which apps consumed the most power in the last 24 hours or 10 days.
- Background app refresh, high screen brightness, location services running constantly, and weak signal strength are the four biggest battery drains on most iPhones.
- Turn off location services for individual apps in Settings > Privacy > Location Services, not for all apps at once unless you need to.
- A battery that has completed 500 or more full charge cycles will hold noticeably less charge than a new battery, and Apple can replace it.
How to check which apps are using the most battery
Go to Settings, then tap Battery. You will see a section called Battery Health & Charging at the top. Below that, you will see a list of apps ranked by how much battery they used. Tap the toggle next to "Last 24 Hours" or "Last 10 Days" to switch between the two views. The 10-day view is more useful if you are trying to spot a pattern, because one heavy-use day can skew the 24-hour view.
The percentage next to each app shows how much of your total battery that app consumed. If one app is using more than 20 percent of your battery and you rarely use it, that is unusual and worth investigating. If the top app is one you use constantly — like Messages, Mail, or your camera — high battery use is normal.
Some apps, like Maps or Spotify, will naturally use more battery than others. Maps drains battery because it uses GPS, your screen, and cellular data all at once. Spotify drains battery because it is playing audio and connecting to the internet continuously. This is expected behavior, not a sign something is wrong.
Background app refresh and location services
Background app refresh lets apps update their content even when you are not using them. Mail can fetch new messages, Weather can update the forecast, and News apps can refresh their feeds. This happens in the background and uses battery. You can turn it off entirely in Settings > General > Background App Refresh, but a better approach is to turn it off only for apps that do not need it.
Go to Settings > General > Background App Refresh and scroll through the list. Turn off the toggle for apps like Games, Social Media, or Shopping apps that do not need to update when you are not looking at them. Leave it on for Mail, Messages, and any app that sends you notifications you care about.
Location services use GPS, which is one of the most power-hungry features on your phone. Many apps request location permission but do not actually need it constantly. Go to Settings > Privacy & Security > Location Services. You will see a list of apps with a colored arrow next to them. A purple arrow means the app used location in the last 24 hours. Tap each app and change the setting from "Always" or "While Using" to "Never" for any app that does not need to know where you are — like a calculator, notes app, or game.
Screen brightness and display settings
Your screen is often the single largest battery drain on your iPhone. A bright screen uses significantly more power than a dim one. If you have Auto-Brightness turned on, your phone adjusts the brightness based on the light around you, which is more efficient than keeping it at maximum all day. Go to Settings > Display & Brightness and make sure Auto-Brightness is on.
If you spend a lot of time on your phone, consider lowering the maximum brightness even when Auto-Brightness is on. You can also enable Low Power Mode in Settings > Battery, which reduces screen brightness, limits background activity, and slows down performance slightly. Low Power Mode extends battery life by 20 to 30 percent on most phones.
If you have an iPhone 12 or newer, you also have the option to use a lower refresh rate. Go to Settings > Display & Brightness > Motion and turn on Reduce Motion. This lowers the refresh rate from 120 Hz to 60 Hz, which uses less battery but makes scrolling look slightly less smooth.
Weak cellular signal and Wi-Fi searching
When your phone has a weak cellular signal, it works harder to maintain a connection, which drains the battery faster. The same is true if your phone is searching for a Wi-Fi network but cannot find one — it keeps scanning, which uses power. If you are in an area with poor signal, turning on Airplane Mode and then turning Wi-Fi back on (so you use Wi-Fi only) will drain the battery more slowly than letting your phone search for cellular signal.
If you are in a location where you know the signal is weak, you can also turn off 5G in Settings > Cellular > Cellular Data Options > Voice & Data. Your phone will use 4G LTE instead, which uses less battery. 5G is faster but drains the battery noticeably more than 4G.
Battery health and age
Every time you charge your iPhone, the battery loses a tiny amount of capacity. After about 500 full charge cycles, most iPhone batteries hold about 80 percent of their original capacity. After 1000 cycles, they typically hold about 60 percent. You can see your battery's current health in Settings > Battery > Battery Health & Charging, where it shows a percentage.
If your battery health is below 80 percent and your phone is more than two years old, the battery is aging normally. If it is below 80 percent and your phone is less than a year old, something unusual may have happened — either a manufacturing defect or physical damage. Apple will replace the battery for a fee (usually around $70 to $100, depending on your model) if it is no longer under warranty.
Do not rely on third-party battery replacement services unless you cannot reach an Apple Store. Third-party batteries are often lower quality and may not last as long.
Overheating and iOS updates
If your iPhone feels hot to the touch, it is working harder than normal and draining the battery faster. Overheating can happen if you are using a demanding app like a game or video editor, if your phone is in direct sunlight, or if the battery itself is failing. If your phone is hot, stop using it for a few minutes and let it cool down. If it stays hot even when you are not using it, the battery may need replacement.
After you update to a new iOS version, your phone may drain the battery faster for a day or two. This is normal — your phone is indexing files, rebuilding caches, and optimizing apps for the new version. If the drain continues after two days, restart your phone by holding the power button and either volume button, then sliding to power off.
Frequently Asked Questions
Why is my iPhone battery draining so fast all of a sudden?
Check Settings > Battery > Battery Health & Charging to see if one app is using an unusual amount of power. If battery health is below 80 percent, the battery itself may be aging. If you recently updated iOS, wait two days for indexing to finish. If none of these explain it, restart your phone by holding the power button and volume button, then sliding to power off.
Does closing apps in the background actually save battery?
No. Closing apps by swiping them away from the app switcher does not save battery because they are already suspended. The only thing that saves battery is turning off background app refresh for apps that do not need it, or closing an app that is actively running and using power right now.
Is it bad to leave my iPhone plugged in overnight?
No. Modern iPhones stop charging at 100 percent and do not continue to charge, so leaving it plugged in does not damage the battery. However, keeping your phone at 100 percent all the time for months can slightly reduce long-term battery health. If you charge overnight regularly, you can enable Optimized Battery Charging in Settings > Battery > Battery Health & Charging to limit charging to 80 percent until you need the full charge.
Does turning off Bluetooth and Wi-Fi save a lot of battery?
Turning them off saves some battery, but not as much as most people think. Bluetooth and Wi-Fi use far less power than your screen, location services, or background app refresh. Turn them off only if you are not using them and need every bit of battery life. Low Power Mode is a better choice for most situations.
Can I replace my iPhone battery myself?
Apple does not sell batteries for consumer replacement, and opening your phone yourself will void the warranty and may damage it. Go to an Apple Store or an authorized Apple service provider to have the battery replaced. The process takes about an hour and costs between $70 and $100 depending on your model.