We do alot of OFF-ROAD camping without hookups and it is always a must do thing for us to always start out each evening with our battery bank charged up to at least the 90% charge state. Doing small short term charging at different times during the day has never been a good thing for us. Everything usally hits the 50% charge state around 10PM at night when we charge up for an hour here and there.
When our batteries drop to their 50% charge state it always takes us around three hours of generator run time to get the batteries back up to their 90% charge state using the on-board converter/charger unit being run by our generator.
I would think using the smart relays that are on the market these days should allow you to charge your truck camper batteries from your truck alternator setup. The downside of course is have an alternator system setup to charge the additional batteries at the same time and not damage the truck alternator system.
We have followed the golden rule over the years of OFF-ROAD camping to never mess with the truck battery system unless it is designed to charge additional batteries. Keep in mind the truck is the only way to get you back home.
Roy Ken
