We have a 2014 Sunseeker 3010DS, going on a 6 hrs trip tomorrow my House Batteries still have about 3/4 charge do I need to charge the House Batteries or will they charge as I keep driving on my trip...
It is better for the longevity of the battery bank to keep it as near 100% state of charge as is possible. I would plug in if it is easy to do, and let the converter work. That will let you cool down the fridge on 120 volt power, too.