Huawei
Adjust Display Brightness auf Huawei
Display brightness on a Huawei phone can be changed in two places: the quick settings panel or the system settings. Both control the same value, but the settings menu gives you the full slider range and access to related options like adaptive brightness.
To set it manually, open Open the settings ➔ Tap on Display & brightness ➔ Push the bar to the left or right. Dragging the slider left dims the screen, dragging it right brightens it. The change applies immediately, so you can watch the screen react as you move the slider.
Why brightness affects your battery
The display is consistently one of the top three battery consumers on any smartphone. Running the panel at 100 percent brightness for long stretches noticeably shortens the time between charges. Keeping brightness around 40 to 60 percent for indoor use is usually enough for comfortable reading without draining the battery fast.
If the slider keeps jumping back on its own after you adjust it, an automatic brightness feature is likely overriding your setting based on ambient light. Turning that automatic option off in the same display menu gives you full manual control.