[Chuck v]

If you have room for two batteries, consider using two 6 volt golf cart batteries in series to make the 12 volts you need. Charging this series stack is the same as with any lead acid battery, so no need to change the present converter in your RV. I did this to my camp trailer years ago when i did a lot of longer dry camping for deer and elk hunting. The cart batteries are true deep cycle designs with the ability to consistently give at least 80% of rated capacity, unlike a normal automotive 'starting' or even the mixed use 'marine' batteries. Plus they are not that expensive and come in 225 and 250 amp-hour capacities.


A further benefit of cart batteries is the series stack for charging. Charging lead acid batteries in parallel is tricky - you need to have the same age and manufacturer of battery and in the same/similar condition, and you need longer "topping" charging times. While it is a good idea to have same brand and age cart batteries, the series stack is not as critical to charge imbalances as the parallel setup.


As to recharging while camping, my winter hunting camps were not very conducive to solar charging...so I carried a small generator for just charging. It was made by Subaru and gave up to 80 amps at 12 volts and ran on a very small 2 stroke engine using about a quart of fuel per complete recharge. It was not very quiet, but only needed to run for about an hour or two (and there were plenty of chain saws in the woods making more noise that this generator which I ran about once a week.)


Chuck