Trolling motor positive battery lead melting?

[kiltedcelt]

I have a 12v 55# thrust Haswing trolling motor that I'm using on my 14' inflatable boat. I was trying out the motor yesterday trying to figure out what sort of battery life to expect based on run time. Anyway, I intended to use this motor as primary propulsion for the boat. Much of the three hours I was out I was running the motor I was on the highest output setting. At some point the motor must've been drawing too much current and the leads heated up causing the insulation on the positive lead to melt partially. The only other thing I can think is that maybe the connections of the motor leads to the battery may not have been secure enough? I have to admit I really don't know a whole lot about trolling motors so I may need some education on the matter. Can I use this motor as primary propulsion for extended periods at the highest setting, or should I vary the speed between lower settings and higher settings? Or, is this likely more a problem with the connection of the leads? The battery is a Group 27 AGM - Cabela's house brand. The bolts that came with the battery are 1/4x28 bolts that screw in, however the washers seemed to be a bit oversized compared to the diameter of the bolt, so maybe the connection isn't as tight as it could be, allowing the wire to somehow overheat? If this motor can't be used at it's max setting is there some other type of electric that can be, or is there something I can build myself? I'm open to suggestions and advice. A lot of the lakes and bodies of water that I like to go on, only allow paddling or rowing or electric trolling motors - no gas outboards. At some point I would like to get a gas outboard for use in other places but currently can't afford to buy new as far as that goes. Anyway, any suggestions, theories, advice?

 

[glenn property of pam]

Re: Trolling motor positive battery lead melting?

if its a connection problem then the wire will have started to melt its insulation near the connector. (connector got hot and insulation close to it melted) if it was overload condition the whole wire will be showing melted insulation. i have never read the manual on my trolling motor so i dont know if theres a service factor.

 

[Silvertip]

Re: Trolling motor positive battery lead melting?

With proper wiriing and proper (solid) electrical connections, properly sized wire there is no reason the motor cannot be used continuously on the highest speed. It would be rediculous to design one that couldn't. I will assume this is a stern mount motor and the batteery is also stern mounted so the run of wire is quite short. The propblem you are having can indeed be with poor connections at the battery. Ditch the wing nuts and use proper washers and a "wrench" to tighten stainless steel nuts. Also check the motor for fishing line wrapped around the shaft between the prop and the motor housing. Also turn the prop by hand to see if it spins relatively freely. You will feel a slight jerkiness as you turn the prop but it should not feel like it is binding.

 

[kiltedcelt]

Re: Trolling motor positive battery lead melting?

The melting was only right at the inch and a half or so coming from the connector. The motor is indeed stern mount with a short cable. The connectors on the motor have a really large opening as if they're intended to accept up to a 5/16" or 3/8" bolt connection to a battery, however the Cabela's battery uses only the dinky little 1/4" x 28(thread pitch) bolt which screws down into the the battery - no upraised posts or wing nuts. However the washers that came with the battery were almost too large for the 1/4" bolt so that the lock washer on the bolt almost wants to sit down in the hole through the middle of the washers. I hadn't been torquing the bolts down very tight so I'm betting you're correct and this is solely a connection issue. I bought some more stainless washers and I'll see if I can get the proper combination to allow me to cinch everything down nice and tight. I'll go back out again when I'm off in a few days and run it full out again and see what happens. Thanks for the advice.