Camera undetected after removing charger

The camera is often connected through USB bus (even if it is a built in camera).
So: it could help to go into the TLP settings and turn off USB power saving when on battery - for just this device or in general.

will list my laptop’s camera, for instance

TLP also has a graphical UI - as far as I know.
is the name - don’t know whether it is installed by default or not