Hi mike, in Australia we have 4 12v110A batteries and 160w of solar as on wood die overnight.
In the states many use the 6v golf cart batteries as relative in expensive, but if u have only 2 and one goes out u a out of power as u knead to have in pars, but u can have 1or 2 or3 12v and if one goes out u still have power, if planing to use campgrounds 1 is fine if wanting to go bush as we call it u knead more, and either solar or as som has said a generator, hear a Honda 2000w inverter is around $1000 but no good to take to OZ. But u will get most of the money back when selling it.
Frank.