Question... how long should it take to charge 2 6volt batteries when plugged in to shore power? I have a new trailer and have had it plugged in overnight in preparation for a camping trip I'm supposed to leave on today. The batteries were showing empty yesterday. Today only 2 lights are displaying out of 5 on the battery indicator display. I would have thought they would be fully charged by now. This unit has a residential refrigerator in it, so I'm wondering if that's why it's taking so long to charge up.