The TROJAN T-1275 used to be a popular 12VDC Deep Cycle battery choice that gave you 150AHs capacity and would produce 12VDC@20AMPS DC CURRENT for a good 280 minutes(4.6Hrs). One of these is not far away from two of the 6VDC batteries in series giving you 12VDC @ 220Ahs capacity... The two each 6VDC Golf Cart Batteries in series however will give you 12VDC @ 20AMPs for around 447 minutes (7.45Hours)... Lots more power...
Maybe this T-1275 will fit your battery box...
I've always wanted to install a bank of two of these on my trailer tongue area and then an additional two in the back of my truck. Combined together I could get a 12VDC Battery setup with around 600AHs capacity...
Roy Ken
