Hi Max,
I have a 12 volt system running through my house, it powers the smoke detectors the CO2 monitors, kitchen clock, street number out the front, light at the front door and a 12 volt pump in the garage downstairs as a back up if we loose power here and a high water alarm in the sump pit which alarms if the 12 volt pump activates. I have a battery each end of the house and they are on constant trickle charge, battery maintainer and have been for years now. The only time I had trouble with a battery overcharging was when I got smart and hooked it up to a solar panel. It worked fine until the controller stuffed up and cooked one of the batteries. That battery is still connected and works fine just powering my system but if I put any load on it it falls over. Anyway these little trickle chargers don't seem to overcharge the battery. I think they put out 1000 milliamps, which is probably what a battery looses just sitting these
