My Kentucky Fried Fingers

izeman

1 GW
Joined
Jun 21, 2011
Messages
5,131
Location
Vienna, Austria
That's offal! Hope your not hurt bad.

Why the shorted connectors?

:shock:
 
izeman said:
Now i'm also member of the elite club of Kentucky Fried Fingers.
No idea how this happened. I connected the second in parallel battery with XT60 plug. And suddenly a big flash and the XT60s internals where gone and my hand was black.

https://www.dropbox.com/s/9ejnd11oy4k0dak/2018-10-12 at 17.05.28.jpg

Ha-ha,, i love it.. We've all done it, and if you aint... You will! It's a right of passage. There will be an original thread with lots of photos somewhere. Here are a few nasty's.... https://endless-sphere.com/forums/viewtopic.php?f=1&t=46713&hilit=Kff&start=25
 
Nothing will scare this crap outta you faster than accidentally creating a high voltage arc 3 feet from your face and searing your retinas like tuna steaks.

Welcome to the club.
 
The two batteries were exactly the same voltage. The balance connectors of both where already connected to the BMS. I was just connecting the XT60 to the parallel harness. But even if i tried to put them together in reverse this would have been imho impossible.
Luckily i wasn't hurt. A few hours later there are no blisters. I was lucky.
Btw voltage of the pack was only 45V.
 
Glad you are OK!!!, but it could only be two things, as far as I can tell.....

1. A dead short or
2. A huge voltage transfer once connected.

If I am wrong please correct me.

:D
 
e-beach said:
1. A dead short or
2. A huge voltage transfer once connected.

You're correct. I think the same. But both batteries where and still are at the EXACT same voltage. I took them out of the bike just 2h ago, and they have been in parallel before.
I will need to see if it is SOMEHOW possible to short an XT60 plug by putting them together in reverse or somehow else.
 
da34MG3.gif
 
Could the contacts have pushed out of the plastic or been misaligned such that they touched together? Probably hard to figure out what happened unless you can catch all the smoke and reassemble it. Glad your fingers survived.
 
So I read this in the afternoon.
That evening bbuzzaaappp a small star shows up while shorting a couple wires.
Seem to always be looking right at it and think I am paying attention to what I am doing.

Oh well.
Till next time...
 
izeman said:
Haha. Maybe i have to add that i had two glasses of wine before this happened. But i was for sure able to drive, and not drunk. I'm still have the impression that it is IMPOSSIBLE to cause a short with XT60s.
DC voltage can be completely strange in terms of sparking.
I would believe you that there was no short and no voltage difference (so virtually no current flow during plug in) because i had a similar incident and also heard about other cases which were unaccountable.
 
Total longshot here but is it remotely possible that so much static could build up that an initial static spark created an ionized pathway for a larger discharge? Seems theoretically possible but if so I would think things would be spontaneously exploding more often.
 
Had a discussion with maddin88 about that, and he mentioned that we should not be talking about 50V, but 2x 50V = 100V as i was trying to put two batteries together "in reverse". Safety distance rule of thumb on a PCB is 1mm/100V AC, don't know if it is different for DC.
I may try a "laboratory conditions like" test, with big leather gloves, eye protection etc with two 12s LIPO packs and see if it is somehow possible to reproduce this result. shouldn't do any harm as long as the contacts don't weld together. And in that case i still can cut one wire with a side cutter.
What do you think? Should i do it?
 
:shock:

Do it with some friends around so they can enjoy the fireworks as well.

:lol:
 
One of them plugs/ packs must have been wired wrong. You clearly connected black to red, whatever color the wires were.


It could be awhile before you figure out what you did wrong, but something went wrong. When I do it, its always that I wired a plug wrong, or grabbed the wrong plug in a mess of em, and accidentally make that big short.


One way I have done it before, is having the balance plugs wired different than the mains. one in series, one in parallel. But that generally cooks off a balance plug, or the balance board.
 
izeman said:
Haha. Maybe i have to add that i had two glasses of wine before this happened. But i was for sure able to drive, and not drunk. I'm still have the impression that it is IMPOSSIBLE to cause a short with XT60s.
Get some heavy leather gloves and safety glasses. Drink two glasses of wine. Using same connectors. Try to make a spark.

Long sleeve shirt and long pants would also be a good idea when playing with sparks.
 
In your honor, we now have a new emoticon :kff: :lol:
 
I just assumed something had just been re soldered, re wired. That's my favorite way to KFF.

Had to be a short somewhere though.
 
Last weekend i reinstalled the batteries in the bike. I wore glasses and thick leather gloves. Made a video while i connected the plugs. Guess what: Nothing happened. Like several times before.
To make the situation a bit more clear i made some pics of the bike and the connectors:

2018-10-26 at 15.27.45.JPGView attachment 42018-10-26 at 15.29.53.JPGView attachment 2View attachment 12018-10-26 at 15.35.37.JPG
 
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