glamis4X4,
The 6 six volt batteries in series would give you twelve volts. I have read that in this application, both batteries must be matched in amp/hour capacity. Although not scarce, if one were to fail, finding a duplicate might take some legwork.
Two 12 volt batteries in parallel would give you twice the current capacity of a single battery. Wouldn't this be the most desirable for a travel trailer situation...especially if you have a bunch of hungry accessories on board.
I don't fully understand these theories, so this could be bum info. My thought would be to go with whatever the manufacturer put in the trailer originally.
Stuart
