OMG i nearly lost my finger!!

Bat

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:crazy::crazy::crazy:

a fully charged Ultrafire 14500 protected (grey wrapper one) appears to be faulty

2.2V before removing the protection circuit
3.84V-3.85V after removing the PCB & wrapper

bad thing happens when my DMM's red probe touches the positive terminal again to test the voltage
small flame (half the size of the typical lighter flame) bursted out from the vent and *instantly* (less than 0.5 second) ate way a small chip (2mm x 1mm) of my right thumb nail

the culprit:



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Norm

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Moved to Smoke and Fire, Hot Cells and Close Calls - The dangerous side of batteries - Norm
 

ma_sha1

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2.2V before removing the protection circuit
3.84V-3.85V after removing the PCB & wrapper

the culprit:

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Why are you trying remove the protection circuit? The culprit is yourself, really, toss it if something goes wrong.
I've shorted DX C-lion unprotected several times, no flame no nothing.

I think the battery was damaged despite first read 3.8V, don't try to remove the protection & try to save the unprotected battery behind it
 

kramer5150

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YOU removed the protection circuit PCBA and you are blaming the product manufacturer??

NO GOOD can come from dismantling protection circuits, or removing heatshrink wrappers.... this should NEVER be done!!! That cell in your top pic with the heatshrink wrappers removed is millimeters away from a dead short across -B and +B.
 

subwoofer

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YOU removed the protection circuit PCBA and you are blaming the product manufacturer??

NO GOOD can come from dismantling protection circuits, or removing heatshrink wrappers.... this should NEVER be done!!! That cell in your top pic with the heatshrink wrappers removed is millimeters away from a dead short across -B and +B.

I'm afraid I agree. If you mess with it you take a risk. If you had done this with any other brand (stripped off the wrapper and protection circuit and then shorted it) you probably would have got a similar result.

Everyone, please handle Li-ions with care and don't go modifying them. If you have a faulty one, contact the supplier or just recycle it.

Safety first!
 

Bat

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yep i shouldn't strip off the wrapper, but the battery was kind of new (1-2 week old only, & barely used for 1-3 cycles maybe?)

i brought it to a local li-ion battery recycling bin afterwards..
 

LuxLuthor

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I have to agree with the others. Perhaps you should go back to your first post and change the image following "Culprit:" to a picture of a bat? As crappy as that brand is....this was a self-inflicted wound. :)

It is one that others may be able to learn from, so thanks for sharing it with us.
 

cdrake261

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I bought a pair of ultrafires like you got there, one measured at 3.7v and the other measured at 1.8v...I sent those suckers back as fast as I could! I like my fingers
 

Cobrala

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Sep 16, 2011
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Glad to see you weren't seriously injured! I guess the product lived up to it's name.

hahahaha that's hilarious. i will not use whateverfire batteries at all. i do not like protected batteries because there is too much to go wrong. the strip that runs alongside the battery that connects the pcb is probably the culprit. did you strip off the plastic wrapper?
 
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