All the 12v systems work with battery connected or disconnected.
Yes it's really old unit as the pup is a 74. I will try to post some pics of it. I have just been using a regular battery charger to do the charging and have had no issues with doing so. I was just curious about my converter as a charge unit. having said that I took the unit out and in the back there was no tranformer big enough in there to do any reall charging so I'll just go on doing what I have been doing for years now. Thanks for your help anyhow!Karl said:Hmmm... Can't find anything with that model number. Can you take a picture or two of it, including the label(s) and post them here? Sounds like it's a really, really old unit, and chances are it won't do a proper job of charging your batteries. Most people use 3-stage chargers/converters that won't fry them by overcharging. Might be time for an upgrade
In my rig, when I hit the disconnect switch for the coach batteries, my converter will not charge the coach batteries whether I'm hooked up to shore power or running the generator.