ok so i got a dual alt bracket from dc power with my stock alternator on the stock location and my dc power alt on the bracket. stock alt charges my stock electrical and DC Power alt charges my sub amp (sounddigital 12k) i would like to use 16v batterys. that means my alt need to charge @ 18volts rigth ? what do i need to do to my alternator in order to do this?///voltage regulator? or is it even possible?... idk... please help btw my truck its a 05 f150 5.4l engine.