In addition to all the ways you can manually extend your battery life, Apple has added a great new feature in iOS 9 called Low Power Mode that can automatically take care of battery-hungry processes for you to squeeze some extra usage out of your iPhone.
Low Power Mode disables features like background app refresh and automatic email fetching to save power. It also stops all automatic downloads and reduces some of the subtle visual effects of iOS. What’s nice about Low Power Mode over an alternative like Airplane Mode is that you can still use functions like Wi-Fi, Bluetooth and cellular connections. It cuts down on features that shouldn’t limit your normal usage of the device too much.
By default, your iPhone will prompt you with a notification when your battery drops to 20% to ask if you’d like to turn Low Power Mode on. Tap Continue to turn it on, or Cancel to leave it and be notified again at 10% battery. When you get the chance to plug back into power, iOS will automatically disable Low Power Mode when you get back up to 80% charge.
If you wish to manually activate the feature without waiting for a notification, you can toggle it on and off from the Battery section of the Settings app. The battery icon in the top right turns yellow to let you know when Low Power is on.