Hi

Ok it sounds dumb but I plug in the shore power and I assume the batteries are charging automatically yes/no? Oh it's the 2001 Scarab, I wish there was an owners manual but then what fun would that be

depends on how its wired in the boat......most likely it goes through a distribution panel...you would need to flip the breaker for the 110V and then most likely flip the breaker for the batt charger. Easiest thing you can do is hook up the shore power and put a volt meter on the batt posts and read the voltage....when charging it should be 13v+
My dads battery is on a float charger in my garage right now and i happened to measure it last night...reading was 13.4V

Thanks, I'll try that to determine what starts the system charging.