Battery/trolling motor cables are melted....??

[RJMOEN]

Went to change out my depth finder today to a new model and found my wires had looked hot. I do have a 2bank battery charger connected...havnt seem to have any problems in the past. Any idea what would cause this?

[jentz]

If those are troling motor cables that are melted Their are way undersized!Minimum should be 8GA cable.They look awful light.

[RJMOEN]

It is a trolling motor cable, they are the ones coming from manufacturer directly connected to motor. As you can see in the other picture it almost looks like the post melted the battery case a little as well....

[mallardnwalleye]

As someone said to heavy a draw amps through too small a gauge/ or too long of a wire. It could be a short (+- being connected). I have seen wires melted and batteries blow up from this and I once had a fire on my boat seat from this.

[mallardnwalleye]

corrosion on terminals-wires as well as kincks can effectively "narrow the gauge" causing this. Clean them up and and check for shorts or kinks.

[Esox_Magnum]

To small of wire and to heavy of amp draw, many companies undersize wireing to save a buck and then we go adding more powerfull trolling motors, personaly I rerig any boat I get with 6ga....

[jmd1]

but remember you need to allow the flow to continue. if you change the hot side you should also change the ground for free flow back to the battery.

[Esox_Magnum]

Finder should be hooked up to the cranking battery not the trolling battery also...

[RJMOEN]

I definitely wont be hooking up my new 500$ fishfinder to this battery...but as for changing the wiring...that isnt the boat wiring that looks corroded and melted it is the wire coming directly out of the trolling motor...cheap 30lbs motor guide unit. I do plan on cutting that chunk out and reattaching new terminals to the trolling motor cable.

[hydro]

Sorry to all the “too small wire” posters, but the problem identifies itself in the photo of the burnt terminal insulation. The melted insulation at the ring terminal crimp is creating a localized high resistance in the electrical circuit. With the high current flow required by a trolling motor, any resistance will create heat (here expressed in Watts, see Ohm’s Law), and as heat increases, so does the resistance, creating a “runaway” condition. This principle is exactly the same as the heat created by an electric range, or even by arc welding.

If the wire were indeed too small for the current flow, the ENTIRE wire would show signs of overheating and this is not evident in the photos. Fortunately, the fix here is an easy one. Simply cut the wire back to where the copper strands are bright and clean and attach a new ring terminal to the clean wires. For extra insurance, after crimping, you could solder the joint to prevent the battery acid from creeping into the crimp and corroding the wires later.

[BobT]

Sorry to all the “too small wire” posters, but the problem identifies itself in the photo of the burnt terminal insulation. The melted insulation at the ring terminal crimp is creating a localized high resistance in the electrical circuit. With the high current flow required by a trolling motor, any resistance will create heat (here expressed in Watts, see Ohm’s Law), and as heat increases, so does the resistance, creating a “runaway” condition. This principle is exactly the same as the heat created by an electric range, or even by arc welding.

If the wire were indeed too small for the current flow, the ENTIRE wire would show signs of overheating and this is not evident in the photos. Fortunately, the fix here is an easy one. Simply cut the wire back to where the copper strands are bright and clean and attach a new ring terminal to the clean wires. For extra insurance, after crimping, you could solder the joint to prevent the battery acid from creeping into the crimp and corroding the wires later.

Second this! Crimp-on connectors are notorious for lack of secure connection. In my designs I actually indicate NOT to use crimp-on terminal connections because we always have trouble with durability. Soldering them is a good way to reduce this issue.

[RJMOEN]

Well alright....thanks guys!!

[delcecchi]

Soldering is good unless there is vibration. Properly crimped connectors are very good. Badly crimped connectors very bad.

[SpecialK]

If you are having problems with soldered connections and vibration, you are not using enough solder.

It's also important to use correctly sized terminals for the guage wire you are using. i.e. Don't use a terminal made for 12ga wire with 14 ga wire.

[BobT]

Soldering is good unless there is vibration. Properly crimped connectors are very good. Badly crimped connectors very bad.

I have to respectfully disagree. In our machine designs we see too many problems with crimped connectors. Even with screw terminals we run into similar issues. Over time the stranded wires shift and settle and even though the terminals were screwed tight or crimp-on terminals crimped tightly they become lose and need to be tightened up again. That's one of the primary advantages of cage clamp terminals. Because they are spring loaded they maintain that tension automatically as stranded wires shift and settle. There are disadvantages to these as well but that's another thread.

Tinning the wires before crimping and then soldering afterwards would probably be the best solution.

[tonkapat]

You did run a breaker/fuse on the positive wire right?

[hydro]

The heat generated by a high resistance connection will still cause the melting shown, even when fused or protected by a breaker. Follow Bob T's advice and repair the connection correctly.

[delcecchi]

The solder wicks up the wire and makes a stress concentration point which causes fatigue. A properly crimped connection causes the wire to cold weld to the connector due to flow. You do need a quality crimping tool to do it right.

There is a standard by the American Boat and Yacht council (E-11) but unfortunately it costs to download.

[jmd1]

If you look at the other wires, they also show signs of bubbling on the insulation (green wire). While i agree the ring terminal is causing some of the issue, if you are trying to pull more amps from the system than it will allow you will have melted ends and if you notice the other wire under the red wire, looks like a black wire is melted to the red one.

Why not do the job right, get rid of all of it and run one larger wire to a central fuse block, then come off it to the things you want to run? Fix it right the first time and won't have to do it again. Also using a ring terminal that is 3/8 inch to fit the stud correctly is important on all connections. I would heat shrink the ends at the crimp and be done with it no moisture, no solder to worry about leaking down.

Use dielectric grease on the post to help with corrosion and put a cover over the post.

And use the right color wire for positive and ground instead of what is laying around. Identify the wire with wire code or tape. If you simply cut the junk piece out, put a butt connector in to get the proper length you are only adding to a resistance problem later on.