CipherLab RS31 Reference Manual page 41

BATTERY OPTIMIZATION
With Battery optimization enabled for the applications, you can make sure they stay
inactive when your device is idle or when they have not been used for days.
On Battery screen, tap More
1)
On dropdown list, select "All apps", all the applications will be optimized by this function
2)
by default. You can individually turn off the optimization mode of a certain app if you
would like it always activated by tapping on the app name and select "Don't optimize"
and then "DONE".
and then select "Battery optimization".
41
Using the RS31 Mobile Computer