Originally Posted by Too Tall
Two 6 volt batteries from Battery Plus Duracell but made by Deka for $100 each will give you a total of 230 amp hours. That's hard to beat Syria
Costco and Sams Club sell the Interstate 6V golf cart batteries. Mine were $150 for the pair (232AH) from Costco, including tax after core turn-in. Considerably cheaper and more power than dual 12V. I believe my Interstates are 10.75 inches tall, just under 11 inches long, and 7.25 inches wide. They fit snugly into a dual size 24 box, but they fit better than the 24s did. The 12V size 24 batteries actually overlapped the end ridges slightly.
I went to Costco and measured the batteries after accurately measuring the box before I bought any batteries.