3 batteries and wiring options

[wayneo99]

I have searched the forums and still have some questions.

prior to this boat I had the traditional single outbaord with 2 batteries and a dual switch, simple as long as you remembered to switch to 1 or 2 when fishing.

My new used boat has a single outboard with 3 batteries which operates like this.

switch off- engine starts no other components operate.
switch 1- motor and rest of electronics
switch 2- motor and rest of electronics
both same as 1 or 2.

there was a small gauge wire also going inside the engine back to the battery switch as if to charge the other battery when running.

not sure how the previous owner had that wired up.

I changed it to

1 battery wired to bat position 1
2 other batt in parallel wired to switch position 2
no isolator

I would like to have the 3 batteries operate independently of each other and have some common charging system for at least 2 of them when running with out buying $300 worth of do dads.

thanks
wayne

 

[sc_shane]

Re: 3 batteries and wiring options

I found attached this diagram. It shows a 12v refridgerator setup, but you could substitute some heavy electronics or a trolling motor on that particular circuit. In addition to your existing selector, you'd need a generic on\off switch - something like the iboats Part # 9601DP for $30 and an isolator for 1 alternator and 3 batteries - something like the iboats Part # 1703 for $75. That's putting it near $105, but you'll probably need some wire and misc supplies, so I'd say $125 to do it right. I suppose you could get away without the 2nd switch too, ant that might keep you under $100.

This is just something I ran across - there might be better ideas out there - guys?

 

[wayneo99]

Re: 3 batteries and wiring options

afetr thinking about it I wonder if the smaller gauge wire comming from the engine to the common on the switch is for charing 1,2 or both of the other batts when the switch is in that particular position for charging
multiple switches??

 

[sc_shane]

Re: 3 batteries and wiring options

Yeah, I'd say the 2nd switch is overkill unless you wanted a way to ensure whatever is running off that particular battery is not getting juice from the battery...

 

[Dunaruna]

Re: 3 batteries and wiring options

Before you start moving wires about, check the back of the switch. Does the small wire(s) go to a terminal that says "alt' or 'field'?

 

[wayneo99]

Re: 3 batteries and wiring options

http://www.cmsquick.com/tech_03_batsys.html
found this
I like the 3 batt, I alt set up. I plan on using a dual switch instead of the single so I can parallel to the others if I num three goes out.
thanks

 

[sc_shane]

Re: 3 batteries and wiring options

The diagram pictures aren't working in the link unfortunately. Even if you bypass the extra switch, I'd still spend the $75 on the isolator mentioned above. That's cheap insurance for your electronics.

 

[offonleave]

Re: 3 batteries and wiring options

I have a similar problem, but I need to know how to wire my two auxiliary batteries to get 24v for my trolling motor. One is currently run in parralel with the main battery, the other feeds the trolling motor.

I want to use the two auxiliary batteries to get 24 v in position 2 on the switch with the main using position 1.

Any ideas?

Jason

 

[wayneo99]

Re: 3 batteries and wiring options

wrong section