Boat Wiring Question - 2 Batteries

[vista4u2]

I bought basically a basket case bass boat with a 115 Mariner on it. The wiring was nothing but a big convoluted mess and just added confusion as I worked to get the engine going, so to keep things simple, I removed all wiring, got the engine running (great), and now I'm in the process of rewiring the whole thing, that being: engine starting, lights, live wells (2), fish finder and trolling motor. My idea is to use 2 batteries, run in parrellel to maintain 12 volts, but this of course, doubles my amperage (Ohms Law). I don't think there should be a problem with this, but correct me if I am wrong. If it is OK, should each system be on a seperate fused circuit, if so, what size fuse should I use? Any suggestions/advise would be nice, I am in the early stages of this project, and can easily change horses in mid stream if needed. Thanks!

 

[karrick]

Re: Boat Wiring Question - 2 Batteries

I would suggest wiring the batteries seperately. Using one for your trolling motor and the other for starting and accesories. I would make sure the starting battery is a deep cycle plus starting, so you have the cca's, and can also deep cycle it. It gives you more options.

 

[JB]

Re: Boat Wiring Question - 2 Batteries

Moving to Boats

 

[KM2]

Re: Boat Wiring Question - 2 Batteries

I'm with Karrick. Most boats that I'm familar with set up the wiring seperate. One battery for starting and accessories the second for trollimg motor only. <br /><br />Connecting the two you risk running your trolling motor too long and not having enough power to start your outboard.

 

[HEDJUG]

Re: Boat Wiring Question - 2 Batteries

With batteries in parallel, you are limited by the weakest battery. If one starts to go bad, it will drag the other with it. If the batteries are run as seperate circuits for engine starting vs. misc equipment you risk losing one of the batteriesand it's assoc. circuits.<br />A good and common practice is to install a Guest type switch that allows you to choose battery #1, #2 or both in parrallel.<br /><br />Hedjug

 

[vista4u2]

Re: Boat Wiring Question - 2 Batteries

I was beginning to be swayed, but the last comment now has me convinced... one battery for the trolling motor, and starting and accessories on the other. By coincidence I just found a "one, either or both" battery switches on Ebay. That is the ultimate solution. Thanks for the knowledgeable input guys!

 

[red10]

Re: Boat Wiring Question - 2 Batteries

you should probably run each piece of equipment to a fused panel so that each item is protected in case of meltdown