This info was lifted from the Apple website in August 2016 and only pertains to iOS devices. The info will likely update the info from time to time so you may want to check this link for updates: http://www.apple.com/batteries/maximizing-performance.
Always make sure your device is using the latest version of iOS.
- If you are using iOS 5 or later, see if you need an update. Go to Settings > General > Software Update.
- If an update is available, you can plug your device into a power source and update wirelessly or plug it into your computer and update with the latest version of iTunes.
There are two simple ways you can preserve battery life — no matter how you use your device: adjust your screen brightness and use Wi-Fi.
Dim the screen or turn on Auto-Brightness to extend battery life.
- To dim, swipe up from the bottom of any screen to open Control Center and drag the Brightness slider to the left.
- Auto-Brightness adjusts your screen to lighting conditions automatically. To activate it, go to Settings > Display & Brightness and set Auto-Brightness to On.
When you use your device to access data, a Wi-Fi connection uses less power than a cellular network — so keep Wi-Fi on at all times. There are two ways to turn on Wi-Fi:
- Swipe up to open Control Center, tap the Wi-Fi icon, and log in to a Wi-Fi network.
- Go to Settings > Wi-Fi to access a Wi-Fi network.
Introduced with iOS 9, Low Power Mode is an easy way to extend the battery life of your iPhone when it starts to get low. Your iPhone lets you know when your battery level goes down to 20%, and again at 10%, and lets you turn on Low Power Mode with one tap. Or you can enable it by going to Settings > Battery. Low Power Mode reduces display brightness, optimizes device performance, and minimizes system animations. Apps including Mail will not download content in the background, and features like AirDrop, iCloud sync, and Continuity will be disabled. You can still use key functions like making and receiving phone calls, email, and messages, accessing the Internet, and more. And when your phone charges up again, Low Power Mode automatically switches off.
iOS 9 is designed to be the most battery-efficient iOS ever. And it gives you more precise ways to manage your device’s battery life, because you can see the proportion of your battery used by each app (unless the device is charging). To view your usage, go to Settings > Battery.
Here are the messages you may see listed below the apps you’ve been using:
Background Activity. This indicates that the battery was used by the app while it was in the background — that is, while you were using another app.
- To improve battery life, you can turn off the feature that allows apps to refresh in the background. Go to Settings > General > Background App Refresh and set the switch to Off.
- If the Mail app lists Background Activity, you can choose to fetch data manually or increase the fetch interval. Go to Settings > Mail, Contacts, Calendars > Fetch New Data.
Location and Background Location. This indicates that the app is using location services.
- You can optimize your battery life by turning off Location Services for the app. Turn off in Settings > Privacy > Location Services.
- In Location Services, you can see each app listed with its permission setting. Apps that recently used location services have an indicator next to the on/off switch.
Home & Lock Screen. This indicates that the Home screen or Lock screen was displayed on your device. For example, the display was awakened by pressing the Home button or by a notification.
- If an app frequently wakes your display with notifications, you can turn off push notifications for the app in Settings > Notifications. Tap App and set Allow Notifications to Off.
No Cell Coverage and Low Signal. This indicates that either you are in a poor cell coverage area and your iOS device is searching for a better signal or that you’ve used your device in low-signal conditions, which has affected your battery life.
- You can optimize your battery life by turning on Airplane mode. Swipe up to open Control Center and tap the Airplane mode icon. Note that you cannot make or receive calls while in Airplane mode.