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