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Sep 07, 2001, 10:07 PM
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Andy W's Avatar


I'm in shock..
some of you may recall the mess my 10x500AR pack was in a couple of weeks ago. The old 'black wire', everyone said. A lot of discussion, now lost, and I put that pack up on the shelf.
In preparation for flying tomorrow, I decided to check out the 10xSR500Max pack I have.. I'd already pulled the shrink back, no sign of problems on those cells. Tonite, I pulled the connector and the negative lead just pulled right off! The black wire has started working it's way down TOWARDS the -ve end of the pack from the deans connector.
So now I'm worried, I pull open the wire on the -ve lead of the ESC and look what I find - this 'disease' has crossed the connector, and is working it's way up the middle of the copper strands!
<img src=>
Look closely, that crud you see in the middle is what's left of the inner strands.. I'm sure it would continue to eat away the wire. Those loose strands, by the way, were already detached - corrosion right next to the soldered connection.
This is amazing! If I cut the wire off and replace it, and wash the connector in acid or something, will I be ok??

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Sep 07, 2001, 10:12 PM
Registered User
That is spooky. Little duct tape. As good as new. Seriously.....what does the battery end look like? Can you get a close up of just the cooer strands?

Sep 07, 2001, 10:15 PM
Registered User
Should have been cooper strands. Can't see the crud that clearly. Is it a powder or solid?
Sep 07, 2001, 10:17 PM
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Jeff Meyers's Avatar
I saw the special the other night about mold infected homes. Looks like your house has black wire disease. You are just going to have to pack up ALL your RC stuff. Give it to me at the field tommorow and I will rid your equipment of this horrifying disease. It may take me up to a year or so to complete this daunting task.



Sep 07, 2001, 10:28 PM
Registered User
Andy W's Avatar
It's powder.
For tomorrow, I've switched ESC's. I'm going to have to cut open the wire and see how far up it's made it. If it's on the PCB already, then what? How do you kill it?
If it can jump across the connector, what about my charger leads. What about every other pack that's ever been hooked up to my charger? How do I detect it without pulling every pack's -ve lead apart?
Sep 07, 2001, 10:53 PM
Too young to be a senior.
planecrash's Avatar
Is there anyway you can tell if your packs have blackwire withour ripping it open? Im starting to think about my packs now.
Sep 07, 2001, 11:17 PM
Registered User
This has happened to me before. It could be from the flux you use to prep your solder joints or the type of solder you are using. The two might not be compatible with each other, or the wire you are using. Andy aprox how old is the solder joint? I would be suprised if it jumped connectors. You probablly use the same solder, and flux on the esc connector also. Baking soda is good for neutalizing acid corrosion(baby size toothbrush works well. I would replace all the wires. Try a dirrent brand of solder, and flux from a reputable electronics store(I do not buy it from RS, but that is up to you).

Sep 07, 2001, 11:18 PM
Registered User
I hope the new forum has spel check. I meant different.
Sep 07, 2001, 11:26 PM
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SheldonYoung's Avatar
Black wire disease is caused when the electrolyte in the cells leaks for some reason.

Red Scholefield has some good information on it at

Turns out simple household vinegar is the way to remove it.
Sep 07, 2001, 11:35 PM
Registered User
Sounds reasonable Sheldon. I can see it creeping along the wire, but crossing a Dean's connector. Andy's connector blades don't look black, and blue to me.
Sep 07, 2001, 11:41 PM
Registered User
I use RS rosin core and have not had any problems with power packs.

However, I have had the dread pestilance on some factory reciever packs, all spot welded and crimped! No solder at all involved.

the corrosion was at the plug end of the cable, not the battery end


I threw it all out thereby fixing the problem.


Sep 07, 2001, 11:44 PM
Registered User
Andy W's Avatar
I have about 30 packs, almost all made by myself. I've been using the same (large) spool of professional quality solder for general connections for about 10 years now, and Deans racing solder for packs and cells. It's not the solder or (rosin-cored) flux - I don't use additional flux. The pack that went bad started it - the wires were corroded completely at the pack, but partially at the connector. The wire from the connector to the ESC is corroding in that direction. The wire from the other 10x500 pack I have (that was flown on this ESC) is corroding from the connector back towards the cells - the end of the wire at the cells themselves is fine, as is the wire nearest the ESC. It's literally eating it's way along from the bad back, ACROSS the connector (that is in perfect visible condition), towards anything else physically connected to it!
My charger leads appear fine - I use 12ga wire here, but not copper - it's Deans Ultra wire, some other very low resistance material (silver in color, very fine strands) - perhaps this halted the spread? I use Deans wire for most of my packs, although I know I have a lot of copper in my collection. I'm going to pull the connectors off, shorten (and inspect) all the negative wires, and reattach..
Just damn..
Sep 07, 2001, 11:46 PM
Registered User
Another thought!

Why is it always on the black wire?

The red wire on my problem packs were as new.

If the problem is fumes, solder, or microbes, it should affect both wires.

Must be something in the black insuluation plastic the the Asian mfgs use.

Sep 08, 2001, 12:28 AM
Registered User
Can't hang this one on the Pacific rim. I've seen good ol' made in U.S.A. wire affected with this malady. Even had some come direct from the factory. BTW none of it ever came close to a battery.
Sep 08, 2001, 03:00 AM
Registered User
Now I seem to remember one or two of my posts...

It's not all bad, but don't even think of trying to re-use any low cost items that have been in contact for any period. If you remove the cable (and everything attached to it) from the ESC then you should be able to solder a new cable to the ESC - not so sure I would want to dip the ESC in vinegar though! If the ESC will not take solder, the ESC is affected and that is the time for it to go in the bin - but having found the problem early I'm sure it will be fine.

Best regards, John