EP 4200 blew up in my face today.
#1
EP 4200 blew up in my face today.
I had bought two new trinity matched EP 4200 packs and started building them today. I discharged all the cells to 0.90 volts and began soldering the bars on. Half way done soldering the pack I had my iron on one of the cells for about three seconds. After that things went fast, but I remember an extremely loud bang coupled with a burning sensation on the upper part of my face. I washed all the acid off my face and flushed my eyes. Long story short my vision was blured for hours, I have tiny pieces of metal imbedded into my skin, hopefully not my eyes, and was in pain for quite a while. I am still trying to contact trinity, thier office must be closed. It was a frightening experience. I have been an electric enthusiast for a long time. With the recent talk about batteries exploding, catching fire, and un-reliability being more common, NiMh and Li-Po alike, this might be the end for electric with me. I very could have lost an eye from the cap blowing off the cell. I will not buy another product from trinity. If this pack was matched from them, how did it explode while being soldered? Stories of EP's failng is becoming more common also. These cells are thought to be more durable but recent stories are telling the opposite. I thought this information should be put out for people to see. A fair warning, friendly advice, and a saftey precaution.
Thanks,
-RCRoads
Thanks,
-RCRoads
#3
were the cells hot from being discharged?
#5
Yes it was the positve side that I was soldering at the time. It is also the side that blew off. The negative side is severly bulged and was supported by the battery jig. There is no evidence of shorting. The shrink wrap and label around the cell still looks brand new. No burn marks what so ever. I even double shrinked wrapped these cells. Plus I had the iron on top of the battery bar making it even more difficult to short it. Even if it was a short, it would have to be shorted for much longer than the few seconds I had the iron on it before it blew. And yes the polarities were correct. There were about seven people in the general area at the hobby shop when it happened and no one noticed anything unusual about the pack.
The cells were at room temperature when I was building them.
The cells were at room temperature when I was building them.
#6
Scary, looks like so dangerous in actual era to join RC.
Because mostly people told me to EP batteries, which are much reliable and less trouble than IB, but until now i must not to be so much confidence.
GP ones are the best, at least you must not to worry to blow.
Because mostly people told me to EP batteries, which are much reliable and less trouble than IB, but until now i must not to be so much confidence.
GP ones are the best, at least you must not to worry to blow.
Last edited by mac853; 10-30-2007 at 07:41 AM.
#9
Tech Master
iTrader: (1)
that looks more like a pressure blow off than anything else, you didn't accidentaly block the vents in the cell?? Also, why are you guys double shrink wrappin, it just makes it harder for these cells to lose their heat.
Hope the injuries heal, I think Trinity need to at least carry out an investigation into this though.
Hope the injuries heal, I think Trinity need to at least carry out an investigation into this though.
#12
Hold on, which generation EP is this one? M2 or M3, maybe the matched ones are still M2, isn't it?
#13
they should just put a stop to battery development. they should of done it a year ago.
just say 3800mah and thats it, no more.
but no they said instead change to 5 cell rule
just say 3800mah and thats it, no more.
but no they said instead change to 5 cell rule
#14
Tech Master
iTrader: (1)
as for the cell, i would guess, looking at the pics, the top part of the cell wasn't assembled correctly, as the rest of the cell seems undamaged, so it wasn't a dead short, just a build up of pressure inside the cell, and then the cap let go.
#15
it matters coz when they try to cram more energy into the same size cell, they are pushing the limits more and more.
this sort of thing never happen to 3800 or 3300, but is common occurance nowadays...
the pic dont show user error to me. he even double wraped it, and its new anyway so the shrink wrap should of been intact anyway.
p.s so tell me what other markets use sub-C cells at 4200mah at 1.25v? i know of none.
in anycase if the cells were not legal then not many people would use them as matchers wouldnt be able to match them for big races and clubs wouldnt allow them and racers wouldnt buy them.
this sort of thing never happen to 3800 or 3300, but is common occurance nowadays...
the pic dont show user error to me. he even double wraped it, and its new anyway so the shrink wrap should of been intact anyway.
p.s so tell me what other markets use sub-C cells at 4200mah at 1.25v? i know of none.
in anycase if the cells were not legal then not many people would use them as matchers wouldnt be able to match them for big races and clubs wouldnt allow them and racers wouldnt buy them.