What guage wire for trolling motor.

[sutor623]

Guys I know this question gets thrown around here all the time. I can figure out the voltage drop with the simple voltage drop calculator, but what percent voltage drop is acceptable in a 12V circuit? I have a 12V 45lb. thrust trolling motor on my transom, and want to run my batteries up front. I have a length of 12AWG wire that has been run from front to back. When I plug in 45A to the calculator, and a 15' length, I get around 20% voltage drop. I think this is a little high. Should I consider running 10G or 8G wire just to be safe? I do not want any fires!!!

 

[sutor623]

Re: What guage wire for trolling motor.

http://www.wattco.net/infopdf/wireguagechart.pdf

According to this, it would be 8 guage, or it would be 6 guage to be super safe......

 

[Silvertip]

Re: What guage wire for trolling motor.

12 gauge wire is too small even if the motor was mounted two feet from the battery. You can look at an "ampacity" chart that shows the maximum current a given conductor size can handle over a given distance. For your boat, the length is 30 feet (up and back). 8 gauge should be fine for that size motor but why not use #6 just in case you up-size the motor in the future. The maximum current draw for your motor will be in the 35 amp range.

 

[sutor623]

Re: What guage wire for trolling motor.

Thanks! Didnt factor in double the length.

 

[sutor623]

Re: What guage wire for trolling motor.

What happens if I run 6 guage to my outlet, and just use the stock wiring from the motor with the plug connected to it? Is this acceptable, or would it be better to wire straight to the motor itself instead of the stock connecting wire?

 

[Silvertip]

Re: What guage wire for trolling motor.

What happens if I run 6 guage to my outlet, and just use the stock wiring from the motor with the plug connected to it? Is this acceptable, or would it be better to wire straight to the motor itself instead of the stock connecting wire?

Not sure I understand your question. The motor is a stern mount -- correct? The battery is up front -- correct? Then run the 6 gauge wire from the battery to a receptacle at the back of the boat. Plug in the motor. You then have a quick disconnect to remove the motor for storage or security. You would not want all that wire permanently attached to the motor and then strung up front to be plugged in up there. Very inconvenient. But then I may have misunderstood what you meant.

 

[sutor623]

Re: What guage wire for trolling motor.

Well, I want an outlet for quick connect, but from the outlet to the motor is a smaller gauge wire. I was wondering if I should beef that up also?

 

[NYBo]

Re: What guage wire for trolling motor.

Well, I want an outlet for quick connect, but from the outlet to the motor is a smaller gauge wire. I was wondering if I should beef that up also?

The original wiring should be fine.