We boondock a lot and have a large Dometic ref. that is a power hog compared to the one we replaced it with. We had a 70 amp converter that would take over 3 hours of charging to bring the 2 golf cart batteries back to full. We have a Solar panel controller that measures battery voltage all the time and charge rates from the panels. The converter would never get to 13.3 volts while running the gen for only 3 hours. You have a better 12 volt system than we do, so once you get accustomed to how it works without shore power, I think you can relax.