Pbois334 wrote:
Thanks for the tips. Think I'll add a second battery and buy two new ones. I will use the camper heater sparingly and sould be fine. If money allows then I will try and pick up a generator as well
If you have the room (height mainly), consider getting a pair of 6V GC2 golf cart batteries and wiring them in series to get 12V. With some shopping around one can often find them for about the same price as 12V marine/RV batteries. The golf cart batteries are a good bit more robust and better suited to realitively deep cycling, which is more or less hard on any lead-acid battery.
Costco and Sam's Club generally have decent prices on GC2 batteries. A local golf cart place also might, or might be pretty spendy; that can vary a lot.