The biggest battery drains on your iPhone

Your iPhone battery drains fastest when the screen is on at high brightness, when apps run location services in the background, and when your phone searches for a weak cellular signal. These three things alone account for most of the battery loss people notice between charges. The screen uses more power than anything else — if you keep brightness at maximum, you can lose 20 to 30 percent of your battery in a few hours of active use.

Background app refresh is the second major drain. Apps like Maps, Weather, and social media apps check for updates and location data even when you are not using them. If you have ten apps set to refresh in the background, your phone is working constantly, even when it is in your pocket. The third drain is cellular signal hunting — when your phone cannot find a strong 4G or 5G signal, it keeps searching, which burns through battery much faster than when you have a full signal bar.

Key Takeaways

  • Screen brightness at maximum drains your battery two to three times faster than brightness at 40 percent, and this is the single largest drain for most users.
  • Background app refresh lets apps update and check location even when closed, and turning it off for apps you do not use constantly can add hours to your battery life.
  • Weak cellular signal forces your phone to search continuously, so switching to Wi-Fi or airplane mode in areas with poor coverage saves significant battery.
  • Location services running constantly for maps, weather, and social apps drain battery faster than any other background process.
  • Older iPhones and phones with degraded batteries drain faster under the same conditions, and iOS can throttle performance to protect the battery.

Screen brightness and display settings

Your screen is the largest power consumer on your iPhone. At maximum brightness, it uses roughly 30 to 40 percent of your total battery per hour of active use. Lowering brightness to 40 to 50 percent cuts that drain by half. The easiest way to manage this is to turn on Auto-Brightness in Settings > Accessibility > Display & Text Size, which adjusts brightness based on the light around you.

The type of display also matters. iPhones with OLED screens (iPhone 12 and newer) use less power when displaying dark colors, because OLED pixels turn off completely for black. iPhones with LCD screens (iPhone 11 and older) light the entire backlight regardless of what color is on screen. If you have an OLED iPhone, switching to Dark Mode in Settings > Display & Brightness saves 10 to 15 percent battery over a full day of use.

Screen timeout also affects battery drain. If your screen stays on for two minutes before locking, it drains faster than if it locks after 30 seconds. Go to Settings > Display & Brightness > Auto-Lock and set it to 30 seconds or 1 minute if you are willing to unlock more often.

Background app refresh and location services

Background app refresh lets apps update their data and check your location even when you are not using them. This is useful for weather, maps, and messaging apps, but it drains battery constantly. You can turn it off entirely in Settings > General > Background App Refresh, or turn it off for individual apps by going to the same menu and toggling off specific apps.

Location services are a subset of background activity that drains battery especially fast. Apps like Maps, Weather, Find My, and social media apps request your location constantly. Go to Settings > Privacy & Security > Location Services and review which apps have permission. For apps that do not need your location (like a calculator or notes app), tap the app name and select "Never". For apps that need location sometimes, select "While Using" instead of "Always".

Some apps request location even when you are not actively using them — for example, a fitness app might track your location for a run you are not currently on. Tap each app in Location Services and ask yourself whether it truly needs your location all the time. Turning off "Always" for five apps can add two to three hours to your battery life.

Cellular signal and network searching

When your iPhone cannot find a strong cellular signal, it keeps searching for one. This searching process uses more power than maintaining a connection to a strong signal. If you work in a building with poor cell coverage, your phone may drain 30 to 50 percent faster than it would in an area with full signal bars.

If you know you will be in an area with weak signal for an extended time, switch to airplane mode or connect to Wi-Fi. Airplane mode turns off all wireless searching, which saves the most battery but also disconnects you from calls and messages. If you want to stay reachable, connect to a Wi-Fi network instead — Wi-Fi uses less power than cellular searching, and your phone will use Wi-Fi for data and calls if you have Wi-Fi calling turned on.

You can check which apps are using cellular data by going to Settings > Cellular and scrolling through the list. Apps that show high usage may be searching for signal or downloading data in the background. Consider turning off cellular access for apps that do not need it.

Bluetooth, Wi-Fi, and always-on features

Bluetooth drains battery when it is on and connected to a device, but the drain is small — roughly 2 to 5 percent per hour depending on the device. If you are not using Bluetooth headphones or a smartwatch, turn it off in Control Center. The same applies to Wi-Fi: if you are not connected to a network, turn Wi-Fi off to save battery.

Always-on features like Hey Siri, raise to wake, and notifications drain battery by keeping parts of your phone active. If you do not use voice commands, turn off "Listen for 'Hey Siri'" in Settings > Siri & Search. If you do not want your phone to wake when you raise it, turn off "Raise to Wake" in Settings > Display & Brightness. These changes save only 1 to 2 percent per day, but they add up.

Push notifications also drain battery because they wake your screen and trigger sounds or vibrations. If you receive dozens of notifications per hour, consider turning off notifications for apps you do not need to hear from when ready. Go to Settings > Notifications and review each app.

Age of your iPhone and battery health

Older iPhones drain battery faster because the battery itself degrades over time. A battery that is two years old holds roughly 80 to 85 percent of its original charge capacity. A battery that is three to four years old may hold only 70 to 75 percent. This means you get fewer hours of use per charge, even if you change nothing about how you use your phone.

You can check your battery health by going to Settings > Battery > Battery Health & Charging. The number shown is the maximum charge your battery can hold compared to when it was new. If it shows 80 percent or higher, your battery is in good condition. If it shows below 80 percent, your battery is degrading and you may want to consider a replacement.

iOS also includes a feature called Performance Management that slows down your phone when the battery is old or damaged. This is meant to prevent unexpected shutdowns, but it makes your phone feel slower. If your battery health is below 80 percent and you notice your phone is sluggish, a battery replacement will restore both speed and battery life.

Apps that drain battery the most

Certain apps drain battery faster than others. Social media apps like Facebook, Instagram, and TikTok use location services, background refresh, and video playback constantly. Streaming apps like Netflix and YouTube drain battery quickly because the screen is on and the processor is working. Navigation apps like Google Maps and Waze drain battery because they use GPS, screen, and cellular data simultaneously.

You can see which apps are using the most battery by going to Settings > Battery and scrolling down to "Battery Usage by App". The list shows the percentage of battery each app has used over the last 24 hours or the last 10 days. If an app is using more than 10 percent of your battery and you do not use it frequently, consider uninstalling it or turning off its background refresh and location access.

Gaming apps also drain battery quickly because they keep the screen on at high brightness and use the processor intensively. If you play games on your iPhone, expect battery to drain 50 to 70 percent per hour of play.

Frequently Asked Questions

Why does my iPhone battery drain faster in cold weather?

Cold temperatures slow down the chemical reactions inside your battery, which reduces the amount of power it can deliver. Your iPhone may show a lower battery percentage in cold weather, but the battery itself is not damaged. When you warm it up, the battery will return to normal. Extreme cold (below 32°F) can cause temporary shutdown, but this is not permanent.

Does closing apps in the background save battery?

Closing apps manually does not save battery because iOS suspends apps automatically when you switch away from them. The only exception is if an app is actively running in the background (you can see this in Settings > Battery). For most users, closing apps manually makes no difference. Turning off background app refresh for specific apps saves battery; closing them does not.

Should I turn off 5G to save battery?

5G uses more power than 4G LTE, especially when the signal is weak. If you are in an area with weak 5G coverage, your phone may drain battery faster on 5G than on 4G. You can turn off 5G by going to Settings > Cellular > Cellular Data Options > Voice & Data and selecting LTE. If you have strong 5G signal, the difference is small — roughly 5 to 10 percent per day.

Does low power mode actually work?

Low Power Mode reduces screen brightness, limits background activity, and slows down performance to extend battery life by 20 to 30 percent. It works, but it makes your phone noticeably slower. Enable it when your battery is below 20 percent or when you know you will not have access to a charger for several hours. You can turn it on in Settings > Battery > Low Power Mode.

Can I damage my battery by using my iPhone while charging?

Using your iPhone while charging does not damage the battery. The phone will charge more slowly because power is being used, but there is no harm to the battery itself. Modern iPhones have built-in protection that stops charging once the battery reaches 100 percent, so leaving your phone plugged in overnight does not overcharge it.