Our coach (signature) has its original IOTA charger/converter. I'm gonna guess it is neither pricey nor particularly smart. Yet, even with that, we can camp a couple months in one place and not loose water from our single 12V "deep cycle" Wally World battery. Working theory is that there's enough 12V draw while actually camping to keep things from getting out of hand. I don't know what would happen if the coach was simply parked, NOT in use, for that amount of time. For that reason, I turn the battery switch OFF when parked at home but plugged to shore power. I only have to add water about annually.
