Wiring multiple battery sources

[SylvanOwner]

I’ve been working on customizing my 14’ tinny and have now come down to the wiring. I definitely need some help.

 

 

 

I have a bow mount trolling motor with 12v deep-cycle battery as well as 2 12v batteries (small fishfinder style) wired in parallel to supply power to switch panel (bilge, navigation lights and 1 empty switch) fishfinder, and 2 12v plugs. I also often carry an additional deep-cycle battery located at the stern as back-up for bow mount.

 

 

 

What I would like to do is to be able to optionally use either deep-cycle or fishfinder 'parallels' to power switch panel and accessories. I can easily run power supply lines from both of the 2 deep-cycle batteries to the electrical compartment where the 2 fishfinder batteries and switch panel are located, just not sure how to wire the “optional” battery sources. First idea, which is probably easiest is to run power lines to the electrical compartment and just plug/un-plug appropriate power lines depending on what source I wanted to draw from using bullet or spade connectors. Second idea, which would involve some sort of switch to select where to draw power from. Any different/better ways?

 

 

 

I really know very little about electrical so please respond using layman’s terms. Yes, I understand that if I draw power for the fishfinder from the same battery as the bow mount that I may get some interference. This may seem like an odd request/configuration but there are good reasons (mostly….lol) for wanting to do this which range from the boat not always being used with a bow mount to not always being able to charge batteries for several days to being a little over-the-top in building in redundancy/back-up.

[Fisherman]

Are you saying that at present you have the 12V fish finder batteries in parallel with the bow mount trolling motor battery? If so, you are killing the fish finder batteries at the same time. If not, I would leave them (FF) batteries separate, fish finders usually take less than 1 amp/hr to run and with 2 of them, you should be good for a week anyway. If you are using 2 trolling motor batteries, doesn't matter which way you go, in parallel together they will provide twice the time as one alone, so you are no further ahead. Keeping the one trolling battery in case of emergency is a good idea if you're down the river, if you are up --its creek, the current will float you back. You can get a multi position high amperage switch to use either #1, #2, both or both off. You can't wire the FF batteries into that circuit.

[misfish]

You seem to be making things complicated IMO. Leave the DC for the bow mount,and use two 12vt gels for the FF. Im not sure what yer trying to gain here. When I did up my 14 ft tincan,This all I did. I did have a switch pannel that ran off another DC battery. It controlled my night lights and live well and down riggers..

[SylvanOwner]

_{@ Fisherman - the FF batteries are wired in parralel to each other so represent their own stand alone 12v source, each of the 2 deep-cycles also represent their own 12v source.}

_{@ Misfish - what I'm hoping to gain from the complexity is versatility}

 

_{so, if one were determined to do what I'm suggesting what would be the correct way to wire an arrangement of 3 potential 12v sources to provide power to a switch panel (bilge and nav. lights), FF, and 12v plug(s)?}

Edited September 10, 2013 by SylvanOwner

[BillM]

Run all your electronics/bilge/whatever off one 12v source.. Run your other two batteries in parallel and use that for your 12V trolling motor.

[Sinker]

Run all your electronics/bilge/whatever off one 12v source.. Run your other two batteries in parallel and use that for your 12V trolling motor.

What he said.

 

Simple and effective. My TM batteries aren't wired into anything but the TM. Everything else runs off a smaller 12v source.

 

S.