Please add function to Settings/System/System/Battery:
Automatic Energy saving mode after x minutes of inactivity. (with a possibility to enter the wished number of minutes or choosing of some predefinited values).
It’s contrapoductive that a full charged phone, that lies on some place while nobody does anything with it, does not enter the power saving mode but senseless discharges the battery.
Presently there’s only possible to automatically activate the power saving mode depending on the accu charge level (20%, 15%, 10%, 5%, off), or set manually until next time charger is connected. Automatic activating after some minutes of user inactivity, detected by absence of user interaction, would increase battery life easily.