Thanks for the info.There are 225 amp hours in a single 6 volt T105 batt vs 140 amp hours in a single 12v and golf cart batteries are designed to be discharged to a lower state of charge and recover better unlike a conventional 12 volt batt, even the deep cycle ones. Theses batteries weight 62 pounds each which gives you a good idea of how beefy the lead plates are.
They do make 12v golf cart batteries but for me it came down to space and available amp hours.