I put a trickle start type of charger in mine, I can't remember the name. It keeps all the batteries charged, I leave it plugged up all the time at home. If I don't flip the disconnect switch phantom electric users will drain the batteries in a week or so. Mine is also supposed to have a cycle that desulphates and also does not overcharge the batteries. It's been on it 2 years and has done well. I also have a switch that will connect the batteries for additional charging but haven't had to use it. My generator battery is separate and only charges when running, have a switch to turn it off and on.
So far it is all working.
