Originally Posted by unyalli
6 volt batteries are more robust given the same space and balancing the wiring.
Bingo...a couple of dedicated
6v 220AH deep cycle trojans or similar power big 22 cu ft. Samsungs all the time in the class A's. But they DO need to be recharged daily.
The Magnums output will be quite sufficient to power a fridge....but if it is a model with the built in charger...you'll want to make sure that can provide sufficient amps to recharge the batteries from shore power or a generator in a reasonable time. A 50=60 amp charger will be plenty for a 220ah battery bank.
@Glennwest...the answer is there is NO reason to go 6V other than economics. Getting a TRUE DEEP CYCLE (not dual purpose) 12V battery that produces the equivilent 220 amp hours...would require a pair of Group 31's which based on production and use factors will be lots more expensive than golf cart batts...particularly the ones at Sam's or Costco. It is just a matter of amp hours per $$. When the existing pair of 12V's go to the battery dump after their murder...it will be time enough to replace them with a second pair of 6Volts as well...room permitting.
May I suggest that anyone boondocking with a 12V refrig...or boondocking period needs a TRUE battery monitor and it will become the most looked at meter or gauge in the RV. Like this: http://www.jamestowndistributors.com...FWYV7AodxkMAWw
Knowing only voltage means you don't have NEARLY enough info to keep from trashing your expensive batteries.