As mentioned previously, you need to find the specs and determine if the converter/charger is multi-stage or not. If it's a single stage you will boil the water out of the batteries, I speak from experience. A good multi-stage will provide a higher current charge if you have lots of lites on or the batteries are low, As the demand decreases the current will cut back and once there is no load it will drop back again to more of a trickle charge to keep the batteries topped off. But you still need to check the water (if conventional lead/acid) level once in a while.
2011 Chevy Silverado 3500HD LT Ext Cab 4x4 Duramax/Allison, 2016 Redwood 39MB, Disc Brakes, Mor/ryde IS, GY 17.5" H tires, 5.5K Onan, Dual ACs, auto level, auto sat dish, stacked washer/dryer, residential fridge, King sleep number. Michelle & Ann