When manual can give you some pointers, I would still put voltmeter on your system as too many variables.
Newer, better converters are wired parallel to battery and have maintaining mode. Older would switch over most of camper to converter power, leaving only radio and electronic stuff on battery + small charging circuit.
Those usually have fast-charging voltage and left for longer time will boil the battery dry.
So maintaining voltage for led-acid battery is 13.5V.
Any higher than that will shorten battery life.
Also calibrate the meters as in my camper- digital meter shows 0.3v higher than handheld meter.