I currently have 2 batteries and 2 Perko (1-2-all) switches with twin motors, and would like to add 2 deep cycle batteries parallel to run my stereo. Any help on wiring schematic would be appreciated. I would like to be able to charge off the engines as well as my onboard charger which is a 3 bank 30 amp unit.

Thanks Steve

do you have a schematic on how it is wired now?

http://atkinsonelectronics.com/product_pdfs/MBCM-12.pdf

I will see if I can find something any help would be appreciated.

You could do it like I did mine. I have 2 Perko switches. I added a 3rd big deep cycle battery for the stereo.

I have mine wired so that #1 on each switch is connected to each engines primary starting battery. #2 on both switches is connected to the 3rd deep cycle battery. You could wire your 2 extra batteries together and run it the same way. I do not charge the deep cycle with both switches on #2 or both on ALL. Both of my stereo amps are wired directly to the 3rd deep cycle battery.

The way mine is wired, as long as I have 1 good battery, I can start both engines if both switches are set to ALL.

Make sure that if you drain your "stereo" battery down while at anchore you put your battery switch to the other battery to start and let the motors warm up on that other battery. Then swap over to both NOT 2. If you swap to 2 and run that way you put a much higher load on your alternator and it will burn up faster. That is why it is suggested when you do what you are talking about you use an isolator.

This is a great artical on batteries.

http://www.google.com/imgres?imgurl=...26tbs%3Disch:1

The fallowing diagram is probably what you have in your boat now.

Steve, just put more hp power in and then take me for a ride LOL.

Just had my 3rd battery wired this weekend. It is wired so that when I am coving I switch to battery battery side 1 (regular batter and stereo battery). I switch to both when starting and running. Prior to rewiring the stereo battery wasn't being charged by the alternator.

Looking for a diagram for adding two batteries. Currently boat has 2 batteries, isolator, and one switch and a single engine. Looking to add two batteries to the stereo side to make it 3 on stereo side one on starting side.