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EP 4200 blew up in my face today. >

EP 4200 blew up in my face today.

EP 4200 blew up in my face today.

Old 10-31-2007, 05:34 AM
  #16  
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go read the charging recomendations on your cells then dude, it is far lower than what we do, and always has been.

to me, it looks like a mal-formed cell, where the top of the cell hasn't been connected correctly to the can of the cell, it don't matter how much heatshrink is on there.

Remember, these cells are not designed for the purpose OR abuse that we put them through, so you have to accept that the cells will be fragile.
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Old 10-31-2007, 05:36 AM
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so tell me what other markets use sub-C cells at 4200mah at 1.25v?
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Old 10-31-2007, 05:40 AM
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the voltage is there due to the amperage we charge at.

sub-c cells are used as emergency power backup for medical, aerospace and control circuits, they are also used in power tools etc, far FAR bigger markets with far far less abuse to the cell, and they cope with the capacity easily as the cells are not abused.

I enjoy a healthy discussion.
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Old 10-31-2007, 05:43 AM
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1800mah nicads that you find in the electronics store yeah

wont find 4200 EP nimhs anywhere other than RC
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Old 10-31-2007, 05:52 AM
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so you think medical monitor manufacturers go to radioshack/tandy to buy their cells? No, they buy them in by the tray full from the likes of sanyo and gp, what we buy are cells labelled for our market only, but the technology is generic, they maybe alter the balance for performance a little more than a long life cell, but thats it, the technology is the same.
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Old 10-31-2007, 05:54 AM
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Originally Posted by DA_cookie_monst
so you think medical monitor manufacturers go to radioshack/tandy to buy their cells? No, they buy them in by the tray full from the likes of sanyo and gp, what we buy are cells labelled for our market only, but the technology is generic, they maybe alter the balance for performance a little more than a long life cell, but thats it, the technology is the same.
lol nuff said
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Old 10-31-2007, 05:56 AM
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try page three http://www.gpbatteries.co.uk/downloa..._Batteries.pdf

The cell build is the same, just the fact that we feel the need to abuse them and charge at 6A and then try to empty them in 6 mins, thats the killer, plus we apply a blooming great heat to both ends to solder them to.
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Old 11-01-2007, 06:38 AM
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Default lipo and nimh

First off, I am glad you are relatively all right. It could have been much worse.

To the posters on this thread, please don't put lipo and nimh into the same sentence. When is the last time a cased lipo pack caught fire at any track? When is the last time one exploded?

Nimh in r/c has been pushed to the breaking point and the results are obvious. Powertools, medical equipment, and most other electronics are switching or have already switched to li-ion or lipo. Of course this being r/c racing, as soon as lipo becomes the norm, idiots will be charging them at 10amps, shorting them, etc in search of an "edge".

R/C racers have only ourselves to blame for the unreliable, junk batteries that we are using. The last good battery was the gp3300, but its 1.19v and 2.3ir just wasn't enough. We r/c racers need 1.25v and 1.3ir to spend money on and go faster. But I guess all of the battery matchers are happy.

It goes without saying that you should use some eye protection when soldering in general, or when dremeling, etc.
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Old 11-01-2007, 03:21 PM
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Originally Posted by billjacobs
First off, I am glad you are relatively all right. It could have been much worse.
Thanks for your concern, and yes I am pretty much back to normal. My eyes and face no longer hurt. What is really irritating me now is Trinity. I have left three messages with not one attempt of them trying to get back with me. Terrible customer support from a large company. I guess it shows how much they value their products and customers.


Originally Posted by billjacobs
It goes without saying that you should use some eye protection when soldering in general, or when dremeling, etc.
It goes without saying, yes, but how many people will actually do it? Will you? I will from now on only because I had come so close to serious eye injuries.

Take a tip from me, don't hover your face directly over your packs they way I was while building them. Sit back and work on them. If I had done this I would have come out unharmed.

This incident nearly forced me out of electric racing. Not because I am afraid of the batteries, although I am slightly as should everyone, but because I don't want to support a market that is un-safe. We shouldn't have to buy Li-Po sacks and ammo boxes. It's getting ridiculous and I see things getting worse as the batteries get more powerfull without better saftey. The hobby should be fun and worry free. I will stay with electric because I enjoy carpet TC and the cleanliness of it. I will however be an advocate of battery awareness to people at the track and on the forums. If the manufacturers won't do it, then we have to.

Thanks
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Old 11-01-2007, 03:35 PM
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Sorry to hear about your accident. Batteries blowing up really isn't a LiPo problem. The guys with lipo batteries catching fire (they can't blow up...not even possible) are the guys that buy the el-cheapo Ebay-style packs.

If you buy quality LiPo packs, you don't have to worry about them catching fire.
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Old 11-02-2007, 06:10 AM
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Default trinity response and lipo batteries

In terms of Trinity, why would they get back to you. If they express any remorse or admit any liability, they can be sued. They can offer to replace the pack, but why would they do that. Since this happened while soldering the pack, they will blame you, saying you applied to much heat to the cell for too long, etc.

In terms of safety, I am anal enough to not only wear eye protection, but to even wear a respirator mask while soldering or dremeling. Everyone else can do what they want, but I value my health, no matter how small the risk, above r/c.

In regards to LIPO, when has a cased lipo pack ever gone up in flames or exploded? Answer -> never. LIPO are far safer than NIMH, if for nothing else than the fact that r/c racers simply charge them and run them. No soldering, matching, etc. I would suggest than you purchase an orion/peak 3200 LIPO pack and get away from NIMH if you are concerned. I have been using orion LIPO packs for a year and they are still both (I only have and need 2) working great.

Last edited by billjacobs; 11-02-2007 at 10:07 AM.
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Old 11-02-2007, 09:26 AM
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as others have stated, I am glad you are ok and no major harm was done.

I am still waiting for the day this happens to me. I used to keep my charger and batts on a shelf so they could be at eye level, but i don't do that anymore for this very reason.

any battery, Lipo or NIMH needs to be treated with the upmost respect and we as users need to realize that things like this can and DO happen. We can complain about reliablity all we want - but the facts are - right now we seem to have very unstable cells. Therefore we need to take precautions when dealing with all these types of cells. I have seen 2 lipo's go up in flames as well as countless NIMH shotguns.

I wish we didn't have to deal with all of this - but if we want to race electric - we really do not have any options. I wish we had more reliable equipment at right now, but we don't, therefore - caveat empor - buyer beware!
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Old 11-02-2007, 10:09 AM
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were the 2 lipos you saw flame up cased? kokam?
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Old 11-02-2007, 10:21 AM
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Originally Posted by billjacobs
were the 2 lipos you saw flame up cased? kokam?
Orion ones are from Kokam, if i am not wrong!
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Old 11-02-2007, 12:47 PM
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I don't want to start a new thread so I'll just post on this one:

I have 2 packs of EP4200's and I was impressed with their performance and durability. I bought another EP4200 pack last week and it came with a dead cell. I was hoping that I wouldn't have to deal with that kind of BS now that I no longer use IB's. Oh well, I only have to use NIMH for 3 more months and then it's all lipo for me.
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