We have the Samsung fridge in ours with a 1000 watt PSW inverter and 2 6 volt batteries. We spend 3 to 4 months ago year in it and have put in a number of 12 to 14 hour travel days. We always run the inverter and fridge and the lowest I have ever seen the voltage registered on the inverter at the end of a travel day is 12.3 volts. Of course, the charge line from the truck is helping but I'm not sure how much. Since we rarely open it while traveling I'm not sure how much it actually runs during the day. We have never spent a night without hook ups so I'm not much help to you past that. I do know that 6 years with a Notcold 1200 in a prior motorhome was enough for me.