Quote Originally Posted by EarmarkMarine View Post
Al,
That is all correct. Technically, you should wire the amplifiers to the positive of one stereo battery and the negative of the other stereo battery and do the same with the charger. In this scenerio its critically important that you begin with two identical stereo batteries in parallel and always keep them as a singular unbroken bank. Also, try and practice this with the alternator feed that comes through the manual or automatic switch plus the ground that comes from the engine block. This way the two stereo batteries will age equally and maintain the same impedance over time which will increase their longevity and maximize your at rest play time over many seasons. Once paralleled (or seriesed for that matter) batteries begin to discharge and charge a little differently it really accelerates degeneration.
David
Earmark Marine

David above you referenced fisherman over working chargers causing them to fail but here you give advice to add a 3rd battery to a dual charging system? isnt this going to overwork it causing excessive heat and premature failure?