Melted Wire - potential causes?

[agannole93]

Was installing a new battery tender over the weekend in advance of hooking up everything for my sound install, and came across this wire in the attached picture. It was going from the house battery switch to the positive post of the house battery. Any recommendations on replacement or potential cause of the damage (and likely fire hazard)? I have no idea when it happened or how long it has been like that. We've had voltage drop on that battery, perhaps this is the cause? Never had a burning smell or anything, but it melted the wire coating and the plastic loom it was wrapped in. Do I need a thicker gauge wire for that 12 inch run, or am I just looking at a faulty wire?

 

[Cobra Jet Steering LLC]

Look up how many amps you are running through that wire and what gauge would be required I think it was just too small of a gauge for what was running through it.

 

[212s]

That looks too thin 6ga (?) for a main battery cable from the battery to the switch. 2ga minimum as it needs to carry 100 amps or more.
Just pick up a standard 12 inch battery cable from your local auto parts store, and some plastic loom to replace it.

This is why fuses are required when you add devices to your boat. The fuse doesn't protect your device, it protects the wiring in your boat if the device shorts and draws too much current which could lead to a fire.

 

[agannole93]

That looks too thin 6ga (?) for a main battery cable from the battery to the switch. 2ga minimum as it needs to carry 100 amps or more.
Just pick up a standard 12 inch battery cable from your local auto parts store, and some plastic loom to replace it.

This is why fuses are required when you add devices to your boat. The fuse doesn't protect your device, it protects the wiring in your boat if the device shorts and draws too much current which could lead to a fire.

@212s I was thinking 4 gauge, you think go to 2? I haven't added anything since purchasing the boat, I'm fusing everything off for the stereo install but that will be isolated and not connected to the battery switch. I think this is likely the case of just using incorrect wire by the previous owner.

 

[Bruce]

Was that a dealer installed battery switch?

Whoever installed it should have used larger wiring.

Not only is wire that is too small dangerous but the heat is the product of lost current reducing how long your battery(s) can support your load.

 

[agannole93]

Was that a dealer installed battery switch?

Whoever installed it should have used larger wiring.

Not only is wire that is too small dangerous but the heat is the product of lost current reducing how long your battery(s) can support your load.

I don't know if it was dealer installed or not, we purchased the boat used and the switch was already installed. I'm combing through the other battery to see if it's a similar issue, but the other side looks fine. Only see this problem on the house side.

 

[212s]

@212s I was thinking 4 gauge, you think go to 2?

Yes, definitely need to get a 2ga battery cable on there...it carries all the current for all devices connected to the switch.

Make sure you check all your black ground cables to make sure they're 2ga battery cables too as they complete the circuit and must be rated the same.

 

[adrianp89]

Yes, definitely need to get a 2ga battery cable on there...it carries all the current for all devices connected to the switch.

Make sure you check all your black ground cables to make sure they're 2ga battery cables too as they complete the circuit and must be rated the same.

This.

Buy some thicker wire. 4 gauge is probably fine. 0 is healthy overkill.