We have had our Heartland since it was new. We are full timers. Our unit has a residential refrigerator. This will only stay on about 3 hours while moving. We have had 3 different Heartland service centers look at it. We were originally told it should last 8 hours. After a factory regional rep looked he said the most we should expect is 3 to 4 hours with the two batteries we have. I was wondering of a larger inverter would be of any use? The ones installed are 1000w. None of the techs mentioned anything about the inverter size. We are sorry we chose this refer option at this point.