Wiring to move the battery forward

[ward cleaver]

Oops, can someone move this to the correct forum?

I have a 14 foot aluminum boat. I want to move weight forward by moving the battery forward of the middle seat. If I did that I would need wiring from the battery to a junction box that I would hook up to with my trolling motor and my fish finder.

What gauge wire do I need to use? Can I use something as simple as a heavy duty extension cord I have laying around? Any reason to put a fuse in the j-box?

 

[oldrudedude]

Re: Wiring to move the battery forward

If the wire core of the extension cord is at least as heavy as the core of the existing trolling motor cable, why not go for it? Keep in mind that extra length or decreased diameter causes power loss through resistance. Ensure the connection are broad and solid. Fusing as close to the battery as possible is a good idea.

 

[F_R]

Re: Wiring to move the battery forward

The cables between the battery and motor must be at least as heavy as the existing ones. In fact, a size larger wouldn't hurt because of the added resistance of the added length. I doubt you have an extension cord that thick.

 

[bob johnson]

Re: Wiring to move the battery forward

can you make the whole run from the battery to the trolling motor?? or you dont want to replace the factory trolling motor cables?

i would avoid making the connection in the midst of a run.

you would be adding connections which are usually the weak spots in the system.

if you must do the connection box thingy.....

id get #6 or #4( even better) battery cable...(tinned if available)

you wont find many extension cords that thick!!!!

bob

 

[ward cleaver]

Re: Wiring to move the battery forward

Sounds like what I need to do is use all the length of the trolling motor cables which would put the jbox on the aft side of the middle seat then go to the battery with a stout set of cables with a minimum length of wiring. What about standard AC wire 12 or 14 gauge? I have plenty of that.

And at the battery I will put in a fuse. I don't have the specs on the trolling motor. Any idea what size fuse I should use? I'm guessing 10 amp.

 

[bob johnson]

Re: Wiring to move the battery forward

trolling motor probably has 20 amp or higher fuse.....12 or 14 wire is way small!!!! but if you got it and blowing fuses is ok....then give it a try...

id at least twist the ends of several #12 wires together for added capacity.

think what the size of the trolling motor cables is telling you...that they think that thickness is ok for the LENGTH of the cables supplied...if they supplied LONGER cables, i bet they would have also been larger dia cables!!

bob

 

[archcycle]

Re: Wiring to move the battery forward

http://www.powerstream.com/Wire_Size.htm
Scroll down to load carrying capacities

There's no reason to guess or speculate on this. If your fuse is too large you can ruin your motor. If your wires are too small you could cause a fire or just melt something regrettable.
Just check the documentation that came with the motor to determine the amp draw, or go to the manufacturer's website and find their phone number and call them, or else just google it.

Then go to that website and find out which wire gauge you need. Do Not skimp on the wiring by using home or automotive wiring! It will corrode and you will wish you just did it right the first time. You can get marine wire cheap on ebay.

 

[ward cleaver]

Re: Wiring to move the battery forward

True or false?

General rule is 1 amp for every pound of thrust for a 12 volt motor.

 

[Silvertip]

Re: Wiring to move the battery forward

True or false?

General rule is 1 amp for every pound of thrust for a 12 volt motor.

Generally true until you get to 40# thrust and larger 12 volt motors. Also when you get into 24 and 36 volt motors things get a little more fuzzy. Household wiring is not suitable for marine use since it is solid strand and therefore not flexible. 12 and 14 gauge are definitely not large enough.

 

[ward cleaver]

Re: Wiring to move the battery forward

Thanks for the reasoning behind why household wiring is not suitable. That makes sense.

I was messing around with the trolling motor and the cables trying to see what my options are when low and behold right there on the cables I discover a manufacturer's tag that says to use a 60 amp breaker. Wow that's way more than I, or anyone else, was thinking. So now that the black arts of electricity have been invoked, this little project isn't looking so good.

But now I realize that I could accomplish my goal of moving weight forward by moving the gas can forward of the middle seat instead of the battery. I even have a long gas line that will support this. So aside from not having easy access to the inline gas bulb what else is going to be a problem with this approach?