From the Settings app, tap Display.
Scroll to and tap Screen timeout.
Select your preferred screen timeout duration.
Decrease the screen timeout to help extend your phone's battery life.
Press the Back button.
Scroll to and tap Brightness level.
Select your preferred brightness level.
Lowering the screen's brightness can help to extend your phone's battery life.
Tap anywhere outside of the Brightness level slider to save your changes.
You've completed the steps!
