Changing the length of time before the lock screen shows up (known as screen timeout), and brightness of your device can impact your battery life. Decreasing the time of inactivity before your device goes to sleep and lowering the brightness of your device can help extend your device's battery life.
1.
From within the Settings app, scroll to and tap Display & Brightness.
2.
From this screen, there are several settings that allow you to manage your screen's display. They include:
Brightness - Drag the slider left and right to adjust the screen's backlight to your preferred brightness.
Auto-Lock - Set the amount of time your device will wait before automatically locking the screen. To preserve battery power and avoid unwanted access, choose a lower setting.
Always On Display - Dims the Lock Screen and displays time, widgets, and notifications visible at a lower power rate when the device is locked. Select this option to customize what is shown during AOD, or turn it off completely.
3.
You've completed the steps!
1.
From within the Settings app, scroll to and tap Display & Brightness.