dhnjosh

I have a 302 with twins, looking to add 2 more batteries for stereo upgrade. Right now I have 2 under the rear seat, with 2 switchs under the seat. One for each engine. 1 on switch is port 2 is starboard. So both batteries are able to turn each engine. What I am wanting to do is add two more to one of the switchs so I have 3 batteries run the amps and house and be able to keep one for engines. I want to keep both switchs wired how they are so each engine can get juice from each bank if needed. Should I just wire two more to one bank parallel, or any suggestions. Or do you think I can get away with only the two batteries? I will be running 2 400x4 JL amps at 2ohm, pushing 4 6.5 JL coxials & 4 7.7 coxials, also 1 600x1 amp at 2ohm pushing 2 10" JL subs. and running fridge in cabin.

Nightlife1970

You will want more batteries if you want to play longer on the hook. If you are keeping the stock alternator you will want to get an isolator for the one bank. I personally just have to batteries on each bank. I run them all, if I actually get to the point that I think my voltage is to low, I just start the boat for a while.

If you really want to run for an extended period get a charger and a generator. I'm sure Irish will chime in he has 6 in his system I think.

dhnjosh

How are your batteries wired on each bank, parallel off each other? Also I do have a onboard shorepower charger under the rear seat, and carry a 1000 watt Yamaha gen. under the back seat so when things get low I fire it up and plug into the shorepower to charge the batteries. Don't think I need the isolator because I won't really rely on just charging off the alts. Boat stays on a lift and is always plugged in to shorepower charging the batteries when not out on the run.

Nightlife1970

Yes I just have my batteries parallel. Putting three on a stock alternator will draw to much current, you will want an isolator.

Irishtornado

I'm running 3 bluetop Optimas 2 on 1 bank(one my stereo is wired to) and 1 on other bank. Then on a isolated switch I'm running 2400 Kinetics all wired to stereo. This is all charged by 275amp Ohio Generator alternators. I have shorepower on my boat with 30amp battery charger so I bought a Honda EU2000i generator I just plug in when I'm going to sit for long periods. Otherwise with my system I'd kill all 5 batteries in a 8hr period.

Hope this helps. I can take pics if you need. Also upgrade wire from alternator it's way to small for anything over stock.

dhnjosh

Yeah Irish if you would take pictures of your setup would like to see it, if you dont mind.

Irishtornado

I'll get some for you when I go home.

OutNumbered

Adding an additional battery per bank I would suggest an isolator or the Blue Sea System Automatic Charging Relay below. Depending on the house load, you can get away with the current alternators. If you don't make long runs above 1200 RPM you may want to upgrade the alternator.

FYI, I did isolate the house load power from the fuse block directly to my house battery. We run an Optima for the house bank and a traditional starting battery for the other. I also plug in to a 20amp 2 bank maintainer when not in use and have great results.

http://bluesea.com/productline/overview/329