8 volt batteries ?!?!

ok i have a massive new system but its not installed yet 2 12inch ma audio hard kore subs 3000 watts a piece and the biggest amp ma audio makes its 4400 watts rms and a 5 farad ma audio cap, my question is ive seen 8 volt batteries in SPL cars but how in the world can i charge them my alternator has a stater on it so it produces 180 amps also and i know that if i put diaodes on the 8 volt batteries the current wont flow back in to the cars 12 volt system so how to I charge the 8 volt batteries. i wanna use 8 volt because when wired together ill get 16 volts and the amp can handle a max if 17.4 volt and when the subs hit the volts will likely drop at peak so 12 volt batteries wont cut it for my system. ne one know how i can charge 8 volt batteries in my car i need the help. i can only find adjustable volt reducers that go from 12 to 6 volts. need the help fast thanks :banghead:

Honestly I know nothing about this, can't help you hear, I will try and get people and send them your way. For more advanced topics, you might want to hit up www.icixsound.com (http://www.icixsound.com)

hadn't heard of the site, haibane - just chk'd it out - thx for passing along...

this is a common set up for SPL monsters .... try hitting up a forum like termpro. They have some B.S. on there (like all other forums I suppose), but they should be able to give you some advice.