Newbie's Project: 2010 Tango Twist 21ft

westend wrote:
... around here, two 6V's are out the door at $190 w/core and tax.

Here in Ontario where the OP is a couple of 6 volt GC-2 lead acid batteries will be quite a bit more than that in Cdn$ but still certainly much less than the $530 Cdn he's already spent for that one G31 AGM. They're certainly also a much better ROI considering a pair of 6 volts such as the Trojan T-105 will offer more than twice the reserve capacity of that G31 AGM. The problem though is the OP seems to think he doesn't have the tongue space on his trailer to mount two batteries.