Have a different behavior when device is connected/disconnected to a power station, or has different battery levels.
There are some features that are not strictly necessary to users although they improve user experience (e.g., UI animations). Moreover, there are operations that do not have high priority and do not need to execute immediately (e.g., backup data in the cloud).
Enable or disable tasks or features according to power status. Since when the device is connected to power, the battery might still be running low, it might be advisable to wait until a pre-defined battery level is reached (or the power save mode is deactivated).
Delay intensive operations such as cloud syncing or image processing until the device is connected to a charger.