Corrosion on Battery Cables question

[rfdfirecaptain]

Recently my #2 battery was not spinning my starter fast enough to start the engine. I checked the battery terminals and found a lot of green corrosion up inside the terminal end of battery cable #2. I decided to do some maintenance on both battery cables. I clipped the cable #2 back in 1 inch increments until all the green corrosion was gone (about 3 inches). I stripped the jacket back with the intentions of adding a new lug. That?s when I discovered the copper wires all had a thin black coating. I checked my #1 battery cable and it?s the same way.

Question #1: Has anyone ever dealt with this before? What did you do?

Question #2: Is the black coating an indication of more trouble to come and that I should purchase new battery cables now?

 

[dingbat]

Re: Corrosion on Battery Cables question

I use the felt anti-corrison pads under my connections. Seems to do the trick

http://www.iboats.com/ANTI-CORROSIO...5759774--session_id.405200392--view_id.931336

 

[rfdfirecaptain]

Re: Corrosion on Battery Cables question

Thanks! I use those pads too, but the question I have is what to do about these cables with this thin black coating on the copper wires.

 

[salty87]

Re: Corrosion on Battery Cables question

cables don't last forever. plastic sheath/coating does little to stop anything, just delays the corrosion.

bend the cables...do they snap, crackle, and pop? new, non-corroded cables don't make those noises.

 

[spoilsofwar]

Re: Corrosion on Battery Cables question

Thanks! I use those pads too, but the question I have is what to do about these cables with this thin black coating on the copper wires.

My guess, and only a guess, is that the black substance is some sort of surface oxidation of the copper from something in the air. I know sulfur gas tends to turn copper black... Could be related to offgassing from charging the batteries if they're of the vented type.

Does the black coating rub off easily, or?

Personally, I would not concern myself with it unless it was the typical heavy green corrosion that happens to battery cables, which you already removed. Crimp some new connectors on them, clean your battery terminals, and spray them both with something like fluid film to prevent future corrosion.

 

[louiefl]

Re: Corrosion on Battery Cables question

Use a blind lug - one with a cup that conceals all the strands of the wires. Also make sure you use adhesive lined shrink tubing that covers the lug and a couple inches back on the wire. It won't stop the existing corrosion, but it will keep the green fuzz from comiing back. Also, check the wires at the engine for the same corrosion.

Once it is all back together, I would measure the voltage drop across the wires. In the ideal world, you will have 13.2 volts measured at the battery and 13.2 volts at the starter. If you have a weak wire or a bad connection, you might only get 12 volts at the starter. The difference between the two (13.2 - 12.0 = 1.2 volts) is the voltage drop. You could simultaneously measure voltage across the battery terminals and across the starter, but that is a litle more complicated than the method below.

Disable the engine so it will crank but not start. Measure voltage from battery positive terminal (not the wire lug) to the starter solenoid - should be zero while sitting there and less than one volt when cranking. You only need to crank for 5 - 10 seconds. A value over one volt means your positive cable is a candidate for replacement. Repeat between the negative terminal and the starter; a high value will mean the negative cable is on its way out.

Concerning the black corrosion on the wire strands, this may be a result of not using marine grade wires with tinned strands. Check your volatage drop, if you are good, then I wouldn't worry about it, but if you do replace, make sure you get marine grade wire - don't cheap out and get the wire from the Depot. Marine grade wire will typically have more fine strands (easier to bend and better long term life when flexing), tinned strands (better corrosion resistance) and a fuel / oil resistant outer coating.

 

[MH Hawker]

Re: Corrosion on Battery Cables question

Replace them

 

[rfdfirecaptain]

Re: Corrosion on Battery Cables question

I agree the black film is probably oxidation. The wires are still flexible… no cracking noises etc. No cracks in the protective jacket either.

I dipped one of my scrap pieces into a about a half inch deep puddle of fluorine acid (AKA aluminum brightener). The copper wires cleaned up easily and they are a dull, but clean copper color all over. I am thinking about using my tortch to tin the ends of this scrap to see how well that works. If all goes well I will do this to both battery cables, at a new lug at the terminal end and seal up the gap around the lug with Plasti-Kote dip.

Thanks for all the opinions and advice.

 

[IllesheimVet]

Re: Corrosion on Battery Cables question

I haven't tried the felt pads, but the automotive battery terminal protective spray works well for me. Re-spray once a year and the terminals will still look like new when you replace the battery.

 

[Bondo]

Re: Corrosion on Battery Cables question

Replace them

Ayuh,.... Agreed,.... The Black part, just ain't Green yet....

I've seen Big wires that would show 12v, but not pass more than a couple of amps.....

As for the felt washers, 'n sprays,...

Ya can't Beat, just plain ole Grease slathered over new Clean connections, for corrosion protection....

 

[bgc]

Re: Corrosion on Battery Cables question

Ayuh,.... Agreed,.... The Black part, just ain't Green yet....

I've seen Big wires that would show 12v, but not pass more than a couple of amps.....

As for the felt washers, 'n sprays,...

Ya can't Beat, just plain ole Grease slathered over new Clean connections, for corrosion protection....

Bearing Grease......

 

[LippCJ7]

Re: Corrosion on Battery Cables question

Pretty simple deal, I would replace them, the black is corrosion and it will make soldering the wire difficult and yet you will still have corrosion within the wires, so by replacing them you are eliminating the corrosion completely.

I much prefer my own cables but I would start from scratch, brand new wires, brand new lugs and brand new heat shrink with heat activated glue. Crimp the ends on and then solder them then heat shrink them and install them, you will not be sorry, Using good corrosion preventatives will help you in the long run but I would certainly replace the old cables.

Just for giggles ohm your old cables out, want to bet there is resistance there?

I'm a professional, this is not my hobby.

 

[sam60]

Re: Corrosion on Battery Cables question

Replace cables and use Noalox on the connections.....preparing to get brow beat by the grease guys..

 

[LippCJ7]

Re: Corrosion on Battery Cables question

Not necessarily mzahn, I agree with noalox, but truth be known axle grease has been used for many years, so it will take some time for the old timers to come on board with noalox, very good stuff and can be used within connections as well.

But to be completely honest here any anti oxidant needs to be reapplied in a boat or any time batteries vent or get knocked around, there are pretty serious acids at work with batteries.

 

[theBrownskull]

Re: Corrosion on Battery Cables question

I would replace the cables and use grease. That is what I have been doing for years and works good.