Thread: Battleborn lithium battery: Melted trolling motor wires

No, the battery isn't too much. The motor will draw only what it needs. You could have a battery 10 times as powerful and the motor would still only draw the current needed. Your problem is that your battery wire was way too small for the amount of current that motor is drawing. Too much current trying to go down too narrow a wire.

What you say makes sense. Why would motorguide have to small of a gauge wire for their product.?
The minn kota battery box is 4 gauge wire. And that is what melted.

Since it melted at the connection, the "restriction" may have been in the way it was crimped rather than the wire itself. In either case, I'd replace it with the next size wire. Cheap insurance.

Thanks Doyle.

I also seen a huge hole at the breaker that was melted in picture 1.

I wonder if I had a failed breaker?

Either way I will replace the breaker and install at factory wires.

I will also move down to a 50 amp breaker for the 55 thrust motorguide.

All connections will be bolted and not crimped.

I think...For a 12 volt 55 thrust motor a 60 amp circuit breaker should be correct. I'm assuming 12 volt not 24 volt.. For the connections I like to use lugs and solder the wires into them. Then add heat shrink over wire end onto the lug. It could be the connection to ground was loose or corroded? Maybe add a new circuit breaker too... Check your spec sheet for correct size for your trolling motor.

You should size your fuse/breaker for the expected full load current. Check with the manufacturer, they will know the what your overload protection needs to be. Then that overload protection will be used to size your wiring. These two aspects of the equation should never be compromised. Fire on a boat is a serious threat and any 12 volt battery has the potential of causing catastrophic damage to your vessel. The other portion of the equation is the length of wires, insulation type, and connection type. I recommend marine grade insulation and mechanical connections using wiring as short as possible. I also recommend upsizing one wire size once you decide your overload protection and length of wire. There are tables you can reference once they are established. My other recommendation would be to treat all connections with a anti-corrosion grease designed for the marine environment and check them regularly for tightness and corrosion. Good luck, you can correct this condition for far less money than another set of those batteries.

Thanks Traveiling man.

I looked up minn kota and I also looked up motorguide requirements as you suggested.

Minn kota has a 60 amp breaker requirement up to 55 thrust and motorguide has a 50 amp breaker requirement up to 55 thrust.

Go figure

Originally Posted by RobertFL

I think...For a 12 volt 55 thrust motor a 60 amp circuit breaker should be correct. I'm assuming 12 volt not 24 volt.. For the connections I like to use lugs and solder the wires into them. Then add heat shrink over wire end onto the lug. It could be the connection to ground was loose or corroded? Maybe add a new circuit breaker too... Check your spec sheet for correct size for your trolling motor.

If you use a 60A circuit breaker you can use #4 wire if the length of wire is 20' or shorter.