Coly, the old saying “more is better” certainly applies to battery’s. Providing you have can carry the weight and have the room I would double up. Personally, I am not an inter state fan so that would change immediately. For those of you on a budget Walmart offers the Everstart brand. There 29 series max deep cycle battery has proven it’s worth in my bass boat. The battery comes with a two year warranty and the two that I had were still good after 6 years. For 100 bucks, I think it’s one of the best deals out there.
On a slightly different note, I recently noticed Everstart is also producing a large agm battery with 900 CCA and a non prorated 5 year warranty, all for 150. For that price with those numbers I will probably use them to replace the oem units that came with my diesel truck when the time right.