People tend to make this solar thing way more complicated than it needs to be. Roy B... 2 120 watt panels on a pop-up? Seriously? What do you want to do- welding? We have a single 135 watt panel with 2 normal size 12 volts on a 34' fifth wheel. We can boondock indefinetly- 14, 20, 30 days without ever running the gen. We have a 400 watt inverter that allows me to run the tv and charge cell phones, computers etc. Yes, we are mindful of our power usage but we do what we want to do. My last set of batteries were still performing fairly well after 5 years so I don't think we abused them. We have installed similar sized systems on numerous friends rigs and they all perform very well.