The fastest way to extend your iPhone's battery is to lower screen brightness and enable Low Power Mode

Your iPhone's screen uses more power than any other component. Turning brightness down to 40 percent or lower, or enabling Auto-Brightness in Settings > Display & Brightness, cuts battery drain noticeably within a day. Low Power Mode — found in Settings > Battery — reduces performance slightly but extends battery life by hours. Turn it on when you hit 20 percent, or enable it earlier if you know you won't have access to a charger.

These two changes alone will add four to eight hours to a full charge cycle, depending on how much you use your phone. They cost nothing and take under two minutes to set up.

Key Takeaways

  • Lowering screen brightness to 40 percent or below and enabling Low Power Mode are the two fastest ways to extend battery life by several hours per day.
  • Background app refresh, location services, and push notifications drain battery constantly even when you are not using your phone — turning these off for apps you do not need saves 15 to 25 percent of daily drain.
  • Keeping your iPhone between 20 and 80 percent charge most of the time, rather than draining it to zero or charging to 100 percent daily, slows the chemical aging of the battery itself.
  • Extreme heat damages battery capacity permanently, so avoid leaving your iPhone in direct sun or in a hot car, even if it is not actively in use.
  • iOS updates often include battery optimizations, so checking Settings > General > Software Update monthly ensures you have the latest efficiency improvements.

Turn off background app refresh for apps you do not actively use

Apps running in the background consume battery even when your screen is off. Go to Settings > General > Background App Refresh and toggle it off for any app you do not need constant updates from — email, social media, news, and weather apps are common culprits. You can turn it off globally or app-by-app.

Most people notice a 10 to 15 percent improvement in daily battery life after disabling background refresh for five or six apps. The trade-off is that those apps will not update until you open them, which is usually not a problem for casual use.

Disable location services for apps that do not need it

GPS and Bluetooth location drain battery faster than almost any other feature. Go to Settings > Privacy & Security > Location Services and review which apps have permission. Change apps like social media, shopping, and news from "Always" or "While Using" to "Never" unless you specifically need them to know where you are.

Maps, weather, and find-my-friends apps genuinely need location. Most others do not. Turning location off for five apps typically saves 8 to 12 percent of daily battery use. You can always turn it back on temporarily if an app asks for it.

Reduce how often your phone checks for new email and notifications

Push notifications — the when ready alerts that pop up on your screen — require your phone to stay partially awake. Go to Settings > Notifications and turn off notifications for apps where you do not need when ready updates. You can also go app-by-app and disable "Allow Notifications" or change the notification style to "Badges" only, which uses less power than sounds or banners.

For email specifically, go to Settings > Mail > Accounts > Fetch New Data and change from "Push" to "Manual" or "Every 30 Minutes" instead. This stops your phone from waking up every time a new message arrives. The difference is usually 5 to 10 percent of daily battery drain.

Keep your battery between 20 and 80 percent most of the time

iPhone batteries degrade chemically over time, and the rate of degradation speeds up when you regularly charge to 100 percent or drain to zero. Apple's Optimized Battery Charging feature, found in Settings > Battery > Battery Health & Management, automatically slows charging to 80 percent overnight if it detects you charge at the same time every night. This extends the lifespan of the physical battery itself.

If you want to go further, try keeping your phone between 20 and 80 percent during the day. This is not necessary for daily use, but it does slow the aging process. After two years of daily charging to 100 percent, a battery typically retains 80 to 85 percent of its original capacity. With Optimized Battery Charging enabled, it often retains 85 to 90 percent.

Avoid heat, which permanently damages battery capacity

Lithium batteries lose capacity permanently when exposed to temperatures above 95°F (35°C). Never leave your iPhone in direct sunlight, in a hot car, or near a heating vent while it is charging. If your phone gets hot during use, close apps and let it cool before charging.

Heat damage is cumulative and irreversible — a single afternoon in a hot car will not destroy your battery, but regular exposure will noticeably reduce its capacity within months. Keeping your phone cool, especially while charging, is one of the most effective ways to preserve battery health over years of use.

Update iOS regularly to get battery optimizations

Apple releases iOS updates roughly monthly, and many of them include improvements to battery efficiency. Go to Settings > General > Software Update to check for updates. Install them as soon as they are available — they often fix battery drain issues in specific apps or features.

If you notice sudden battery drain after an update, restart your phone first. If the drain persists, go to Settings > Battery > Battery Usage to see which apps are consuming the most power. If a single app is using more than 20 percent of daily battery, try uninstalling and reinstalling it, or contact the app developer.

Frequently Asked Questions

Does closing apps in the app switcher save battery?

No. Closing apps manually does not save battery because iOS automatically suspends apps you are not using. Forcing them closed and reopening them later actually uses more power, because your phone has to reload them from scratch. Leave the app switcher alone.

Should I turn off Wi-Fi and Bluetooth to save battery?

Only if you are not using them. Wi-Fi and Bluetooth in standby mode use very little power. Turning them off and back on repeatedly actually drains more battery than leaving them on. Turn them off only if you are in an area with no networks and no Bluetooth devices, or if you are in Low Power Mode.

Why does my battery drain faster in cold weather?

Cold slows the chemical reactions inside the battery, making it temporarily unable to deliver power as quickly. Your iPhone may shut down at 20 percent in freezing weather, even though the battery is not actually empty. Warm it up indoors and the battery will work normally again. Cold does not cause permanent damage the way heat does.

Is it bad to leave my iPhone plugged in overnight?

No, because Optimized Battery Charging slows charging to 80 percent and holds it there until you typically wake up. If you have this feature enabled in Settings > Battery > Battery Health & Management, overnight charging is safe and actually better for long-term battery health than charging during the day.

Can I replace my iPhone battery myself?

Apple offers battery replacement at an Apple Store or authorized service provider for a flat fee that varies by model — typically between $50 and $100. Attempting to replace it yourself voids your warranty and risks damaging other components. If your battery health has dropped below 80 percent, a replacement is usually worth the cost.