Jeez Matt, it's not that dire.
Johnny, you could sure benefit from having two batteries. If you can't find a place for two 6v's in series (which is probably better), join the rest of us living on the edge with two 12's in parallel.
Then figure out how to charge them.
In that order. :)
If your present battery is old and/or abused from undercharging, you might as well start fresh with two new ones at the same time. Otherwise the bad one pulls down the new one.
PS: You could also look into a Wave catalytic heater. No need to derail this thread, you can search on them in the forum. Pros and cons, like everything. But they don't run down your battery.
