Exploded NiCd Batteries

While attempting a home-charge of a set of NiCd batteries, they were
left unattended and consequently exploded (relatively high current was
flowing through them). The basement area in which the explosion took
place is currently being ventilated overnight.

Does anyone have any recommendations for further safety precautions or
clean-up procedures?

Thanks

 

[ehsjr]

hapticz@sbcglobal.net wrote:

i just exploded a NIMH camcorder 3.2 volt can.

i thought ok, i'll just connect this to my lowly wall wart for about 15
minutes. as usual i forgot about it. 1 hr later i hear this hissing high
pressure gass sound, then KABOOOM! and i mean KABOOM! i was louder than an
M80, and inside the house it seemed like an artillery shell had gone off.
then i set about extinguishing the shards of plastic/copper foil and
chemcal fires scattered around the room. very nasty indeed! can had
propelled itself from the tabletop nearly through a sheetrock wall, then
rebounded around a bit.

next time i do it outside , inside a metal fireproof trash container!

Spend a dollar and make a safe 14 hour charger.

-----
DC+ ---Vin|LM317|Vout---+
----- |
Adj [R]
| |
+----------+----> To NiCd +
Gnd -------------------------> To NiCd -

R = (C/10)/1.25 where C is the NiMh or NiCd maH spec.

Your wall wart must be a couple of volts higher
than your NiMh or NiCd pack rated voltage.

This will be safe, even if it goes beyond 14 hours,
but you don't want to leave your pack on it forever.

Ed

then again, the correct charger would avoid all this.