wiring for 3 batteries

dadgummit

Petty Officer 3rd Class
Joined
Dec 30, 2006
Messages
96
What's the best way to wire 3 batteries on an outboard bass boat? The current set up is 2 deep cycles on nothing but the trolling motor, and one dual purpose battery for starting and electronics, nav lights, etc. I would like to keep the starting battery for just that and wire my electronics into one of the batteries from the trolling motor. Thanks.
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: wiring for 3 batteries

Is the troller a 12V or 24V motor? If its a 24V motor, the two troller batteries are in series as shown below. You can wire the accessories DIRECTLY to either battery. DO NOT TAP INTO THE BLACK WIRE IF YOU WIRE TO BATTERY #1 AS THAT WOULD FEED 24V TO THE ACCESSORIES. Don't want that.

24VChargingSystem.jpg


If you have a 12V motor the batteries are wired in parallel as shown below. You can connect the accessories to either battery or directly to the 12V leads - whichever is more convenient.

12VParallelCharging.jpg
 

dadgummit

Petty Officer 3rd Class
Joined
Dec 30, 2006
Messages
96
Re: wiring for 3 batteries

it's a 24volt troll. I just saw the sticky on generic wiring. Is it normal to run all the accessories off of the starting battery? Thanks for the diagram, so I need to keep both connections on either battery? THanks.
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: wiring for 3 batteries

Yes on keeping accessories on the starting battery. Locators, radios, and other stuff generally don't draw that much power and the engine can keep up with it nicely. Radios that have megawatt external amps are another story and should probably have their own deep cycle battery. If you have a 24 volt troller and want 12 volt stuff powered by one of the troller batteries, connect to what I show as BAT 2 in my diagram. Observe the warning if you want to connect to BAT 1.
 
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