Samsung Galaxy S21
My phone's battery life is short
Solution 7 of 15: Mobile data is turned on
You can limit your data usage by turning off mobile data. You'll then not be able to access the internet using the mobile network. You can still use Wi-Fi even though mobile data is turned off.
Slide two fingers downwards starting from the top of the screen.
Press the mobile data icon to turn the function on or off.
Press the Home key to return to the home screen.