Which one would be best? I am still in a dilemma about what I need to do to make sure my electrical system in my car will be able to withstand about 1700 rms power. stock alt has 90 amps. has a stock battery. i was thinking a hc 800 or something along the lines of that. would I need a cap or anything or will this second battery cover voltage drops. also, would my current alt be able to keep both batteries charged? i need some advice fellas. thanks!