I honestly dont think I'd run 2 batteries on a stock alty. That might be too much draw on the stock one and you run the risk of messing it up. Have you thought about replacing the battery under your hood with the optima? By the way thats a good price on that battery. All the one's here local to me are $150+. I do know a few years ago the yellow tops were the choice to go with. Since then a brand called Deka has proven to be just as good a choice as the Optima. Why are you using so many speakers?? I would imagine the comps in the kicks and the 6X9's would be plenty on a good 4 channel. I'm just curious, not downing you by any means.