Ok so real quick if I understand, about these kits being sold at attractive prices here and there, like this one on amazon
https://www.amazon.com/gp/aw/d/B01AXU17UI/ref=mp_s_a_1_3?qid=1464010025&sr=8-3π=SY200_QL40&keywords=rv+solar+panel+kit+400+mppt+-inverter&dpPl=1&dpID=51J0rOsUt-L&ref=plSrchBasically I should build a kit myself? Heavier and longer wire gauge, better charge controller.
Also I'm guessing that panel voltage don't have anything to do with the battery voltage right? 24v vs 12v (2x6v) the charge controller will deal with that?
Just like my trickle charger charged my van's 12v battery from a 110v outlet all winter long in the garage.