Originally Posted by
you da man
I have 3 batteries: 1 for start and boat standard boat accessories/electrical and 2 strictly for stereo. I use a Perko switch and a 20amp onboard 2 bank charger. Our boats only have a 70 amp alternator for the 325 engine and 90 amp for the 340. I would never rely on the boats alternator to charge my stereo batteries. I thought about using isolators and other various electrical devices to decide which battery gets charged but I'd rather have the manual Perko switch. The Perko is not that bad as some people have suggested. Your 2 bank charger, if it's 20amps, will be more than enough to charge a drained battery.