I have a 2008 Honda Accord 2DR. V4 Engine. Right now i have a 400 rms amp running my 4 door speakers. I was going to add a 600 rms infinity amp for the sub. Do i need to get another alternator. Cant i just Add a Kinetic battery? or a capactitator?, becuase i dont want to change my cars altnator. The amps are 4channel SoundStorm 1200 watts max(400), and the other one is 1channel infiity 894 watts max (600rms)