12v group 24 batteries run about 80 amp hours each, so 3 of them would give you about 240 amp hours.
12v group 27 batteries run about 90 amp hours each, so 3 of them would give you about 270 amp hours.
12v group 31 batteries run about 125 amp hours each, so 3 of them would give you about 375 amp hours.
6v golf cart batteries give you about 220 amp hours, so 2 of them give you about 220 amp hours.
This web site has useful general information:
http://www.batterystuff.com/kb/tools/bci-battery-group-sizes.html
