How thick of wire to trolling motor

[Rick G]

I am running a third battery to the front storage area just for my rear mount trolling motor. My question is how thick of wire do I need? I am running it around 18 ft and I have a 55lb motor. My buddie said I could get by with 8ga. and the guy at the local marine dealership said I would need 2ga. Now I know the 2 would be better because it is thicker and therefore less degration of power but do I realy need this thick?

[Esox_Magnum]

I have 6 run from back to front for my bowmount no issues with that. Think I have close to a 20' run.

[stumper]

Do NOT use 8 gauge. 6 will work, but I would recomend heavier. I had 6 get hot on me running full power on a 55 lb V2. Whatever you decide ,make sure you use a good breaker.

[Nick Kuhn]

You can use 8 gauge only if it has a high temperature rating. 6 gauge will be just fine (and have 4% less voltage drop than 8 gauge). It doesn't matter if it gets hot, when soldering it takes several hundred degrees to melt the insulation. It can be too hot to touch but still be within it's operating temperatures.

2 gauge is overkill and more difficult to work with (and not to mention expensive).

[solbes]

I think you may run into voltage loss issues with 8 gage. Virtually none with 4 gage. 2 gage would be more for a long run to start your motor with, way overkill for a 55lb TM. 6 gage would be a nice compromise I would think; it's what I ran from bow to stern on my last boat. If you can find 4 for a similar price to 6, then go for it.

[Larson15]

6 gauge for sure. I wouldn't use anything else but this

[Nick Kuhn]

For the speed you normally use your trolling motor voltage drop will be between 0-4% even with 8 gauge wire, so it's hardly a problem. If you plan on using it at maximum speed for extended periods of time, you may get a loss of up to 10%. And this is with a generous 1 way circuit length of 20 feet. If your boat has the TM battery up front and you can get by with 8-12 feet losses along the wire will be negligible.

[stumper]

You can use 8 gauge only if it has a high temperature rating. 6 gauge will be just fine (and have 4% less voltage drop than 8 gauge). It doesn't matter if it gets hot, when soldering it takes several hundred degrees to melt the insulation. It can be too hot to touch but still be within it's operating temperatures.

2 gauge is overkill and more difficult to work with (and not to mention expensive).

When I say hot I mean it was smoking.

[gunflint]

I use 4 gauge and have never had problems. For years I used old jumper cable.

[fishnowworknever]

Are you using the thick stranded 8ga or the thinner stuff? Thin stranded = less heat

[Rick G]

Thanks for all the help guys. I went with the 6ga. thin stand with a heat rating of 190f. I will take it for a trial run tomorow if the wind stays down enough.