LiFePo4 FTW! (If you use it enough to spend the $$)I have the factory group 31 sitting on the porch (since the two genesis batteries are under the hood). I am planning to put that in the bed but I haven't decided on how to mount it yet. Battery boxes online don't seem to meet all that I am looking for thus far. Hoping to have a solution figured out here in a month or two.