Samsung
Adjust Screen Timeout auf Samsung
Screen timeout defines how long your Samsung display stays on before it goes to sleep automatically. It exists to save battery and prevent the screen from staying lit in your pocket or bag. A short timeout protects battery life but can switch off the display while you are still reading or filling out a form.
Samsung One UI lets you pick a fixed value instead of relying only on the default. Available options typically range from 15 seconds up to 10 minutes, so you can match the setting to how you actually use the phone.
Where to change it
Open Tap on Settings ➔ Tap on Display ➔ Tap on Screen timeout ➔ Choose an option. Pick a shorter value if battery life matters more than convenience, or a longer one if you often read, code, or fill in long forms.
A very long timeout drains the battery faster because the display is one of the biggest power consumers on any phone. A very short timeout can interrupt tasks that need the screen on without you touching it, such as reading a recipe with wet hands. If that is your main issue, look at Samsung's separate smart display features instead of just extending the timeout.