if you have a garage you will come out better trickle charging just one 12V battery over night every night to give your 12V a "surface charge" which would increase your mpg by 2-3mpg. You could "permanently" install one and have the cord come out a side window or something to that effect.
Well Here my situation (or thinkin) I have one yellow top optima 51 already(instlled/required to start). I am not sure how these do with trickle charge. I also have and 2second yellow top optima available that I am not using and am considering installing with positve+ terminal being hookup to the jumper contact inside engine relay compartment. Then negative- just ground to closest body contact... Otherwise I am curious of what any1 had in mind on a 2nd 12volt battery config.
