@Tayhas: I'm not quite sure if I understand the query. For clarity, are you trying to say that your phone is charging very quickly following the update to Android 12, or do you mean that you have to charge it more frequently? If you would like to increase the time it takes to charge the device then please head to Settings > Battery and device care > Battery > More battery settings > Fast charging, and toggle this option off. If you're finding that the battery life has reduced then please head to Battery and device care > Battery > Tap on the usage graph, and check the details below. Can you see any apps or features that are using a lot of battery?
