ok, although i have seen the previous post and done some research my question is not answered. My friend has a 90 plymouth voyager with 2 audiobahn natural sound 500watt RMS 15" subs wired to a kole audio 1440 watt amplifier. Now based on my calculations with a nominal 14.4 volts, the amplifier should be pulling 50 amps. Now he wants to upgrade to 2 more 15's and go with a new MA audio HK598 4 channel amp at 1600 watts RMS being 2 ohm stable. With that picture, the new draw should be about 111 amps. With the current factory alternator assuming it is a 60 amp, would you have to combine the original 60 amp capacity with the new required 111 amps for a 170 amp alternator?? More or less go ahead and go with a 200 amp alt. Along with dry cell batteries, I heard the rule of thumb goes for every 70 amp draw you would need a dry cell, is this true?? If so, would he need two, and how would I go about wiring that from the alt to the batteries to the amplifier??