What drains your iPhone battery fastest
Fast battery drain usually comes from one of three sources: an app running in the background and using power constantly, your screen brightness set high, or your phone searching for a signal in an area with weak coverage. Less often, it is a hardware problem — a battery that has worn out after years of charging, or a component that is drawing power when it should not be.
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 has degraded and will drain faster than it did when new. If it shows 80 percent or higher, the problem is software or signal, not the battery itself.
Start there. If your battery health is good, move to the Background App Refresh section below. If it is below 80 percent, you will need to decide whether to replace the battery or live with shorter battery life.
Key Takeaways
- Check your battery health in Settings > Battery > Battery Health & Charging; if Maximum Capacity is below 80 percent, the battery itself has worn out and needs replacement.
- Background App Refresh is the most common software culprit — apps refreshing data when you are not using them drain power constantly, and you can turn it off per app.
- Screen brightness and location services use significant power; lowering brightness to automatic and turning off location for apps that do not need it saves battery life.
- Weak cellular signal forces your phone to work harder to stay connected, draining the battery faster than normal even when you are not using the phone.
- If battery health is below 80 percent and you use your phone heavily, replacing the battery costs less than a new phone and restores most of the original battery life.
How to find which apps are using the most power
Go to Settings > Battery and scroll down to Battery Usage by App. This list shows which apps have used the most power in the last 24 hours or the last 10 days — tap the toggle at the top to switch between them. Apps at the top of the list are your main power drains.
The list shows two numbers for each app: the percentage of total battery used, and whether that use was on-screen or in the background. If an app shows high background usage but you rarely open it, Background App Refresh is the problem. If an app shows high on-screen usage, you are straightforward using it a lot — that is normal.
Social media apps, maps, and music streaming apps are the heaviest users because they refresh content, track location, or play audio constantly. If one of these apps shows 15 percent or higher of your total battery use and you do not use it that often, turning off Background App Refresh for that app alone will usually make a noticeable difference.
Turning off Background App Refresh for specific apps
Go to Settings > General > Background App Refresh. You will see a list of every app on your phone. The toggle next to each app name controls whether that app can refresh in the background. Turn off the toggle for any app you do not need to update when you are not using it.
You can also turn off Background App Refresh entirely by toggling off the switch at the top of the list, but this will stop all apps from refreshing — email, messages, and news apps will not update until you open them. Most people find it better to leave it on globally and turn it off only for the apps that drain the most power.
After you change these settings, use your phone normally for a day and check Battery Usage again. If the heavy-draining apps now show much lower numbers, Background App Refresh was your problem.
Screen brightness and location services
Your screen uses more power than any other single component. Go to Settings > Display & Brightness and turn on Auto-Brightness. This adjusts brightness based on the light around you instead of staying at a fixed level. If you keep brightness at 100 percent all day, lowering it to 50 percent will extend battery life by several hours.
Location services also drain power because your phone uses GPS, cellular data, and Wi-Fi to pinpoint your location. Go to Settings > Privacy & Security > Location Services and turn off the toggle for any app that does not need to know where you are. Maps and weather apps need location. Games and social media apps usually do not.
If you want location on for some apps but not others, open Location Services, tap each app, and choose Never instead of While Using or Always. This prevents the app from tracking you in the background.
Weak signal and cellular coverage
When your phone has weak cellular signal, it works harder to stay connected — the radio inside is transmitting more power to reach the nearest tower. If you spend most of your day in an area with poor coverage, your battery will drain faster than it would in an area with strong signal, even if you are not actively using the phone.
You can see your signal strength in the status bar at the top of your screen. If you see only one or two dots most of the time, weak signal is contributing to fast drain. Switching to Wi-Fi when available reduces the load on the cellular radio and saves power.
If you are in an area with no signal at all, turn on Airplane Mode to stop the phone from searching for a connection. This is the single fastest way to preserve battery when you know you will not have service for hours.
When your battery has degraded and needs replacement
If Battery Health shows Maximum Capacity below 80 percent, your battery has lost the ability to hold a full charge. A battery at 70 percent capacity will drain twice as fast as a new one because it straightforward cannot store as much energy. This is normal wear — lithium batteries degrade over time, especially if you charge them every day.
Apple offers battery replacement at an Apple Store or through mail-in service. The cost varies by iPhone model but typically ranges from $50 to $70. If your phone is still under warranty or covered by AppleCare+, the replacement may be free or reduced cost.
Third-party repair shops also offer battery replacement, often for less money than Apple charges. If you choose a third-party shop, make sure it is certified and uses genuine or high-quality replacement batteries — cheap batteries may drain faster or fail sooner than the original.
Other settings that affect battery life
Low Power Mode reduces performance and limits background activity to extend battery life. Go to Settings > Battery and turn on Low Power Mode. Your phone will run slower, but battery will last significantly longer. You can set it to turn on automatically when battery reaches 20 percent.
Bluetooth drains power when it is on, even if you are not connected to a device. Turn it off in Control Center or Settings > Bluetooth when you are not using wireless headphones or speakers.
Push notifications wake your screen and use power every time an app sends you a message. Go to Settings > Notifications and turn off Allow Notifications for apps you do not need alerts from.
Visual effects like parallax and transparency use power. Go to Settings > Accessibility > Display & Text Size and turn on Reduce Motion and Increase Contrast to disable these effects.
Frequently Asked Questions
Is it bad to use Low Power Mode all the time?
Low Power Mode reduces performance — apps open slower and some features are disabled — but it does not damage your battery. If you use it only when battery is low, you get the benefit without the slowdown. If you need all-day battery life and do not mind slower performance, using it constantly is fine.
Does closing apps in the background save battery?
No. Closing apps does not save power because iOS suspends apps automatically when you are not using them. The only exception is if an app is actively running in the background — you can see this in Battery Usage by App. For those apps, turning off Background App Refresh is more effective than closing them manually.
Can I replace my iPhone battery myself?
Apple does not sell batteries separately to consumers, and opening your iPhone yourself will void the warranty. If you want to replace the battery, use Apple or a certified repair shop. The process takes one to two hours at most shops.
Why does my battery drain faster in cold weather?
Lithium batteries work less efficiently when cold. Your iPhone may show low battery or shut down temporarily in freezing temperatures, even if the battery health is good. The battery recovers when it warms up — this is not permanent damage.
Does updating to the latest iOS version help with battery drain?
Sometimes. Apple releases updates that fix bugs causing excessive power use. If you are on an older iOS version, updating may improve battery life. If you are already on the latest version and battery drains fast, the problem is not the operating system.