disaster999

iTrader: (1)

got a pack of matched smc battery for about...1.5 years old, at first it charged out fine 3-4 months ago, but recently, the cell seems to die on me! the peak volt of the pack was around 10 volts and only have about 2500mah in it!

anyway i could revive it? or its a goner?

Randy Caster

iTrader: (47)

Try discharging it as low as it will go, then dead short each cell individually. Should erase any memory that the pack has, and may work to revive it.

disaster999

iTrader: (1)

oops i forgot to mention that its 3000mah batt...not nicd!

Randy Caster

iTrader: (47)

Not sure in that case, that worked for me with NiCD batts, never tried it on a NiMH, but I guess it couldn't hurt the cell anymore than it already is.

boner

iTrader: (4)

what kind of 3000? GP or SANYO? your cells are old. just use what you brought over from your home.

Tag

iTrader: (31)

i know dead shorting is commonly used for nicad but i had tried with a dying gp3300 with good result. I have a set of dying 3300 , peak around 10V and only about 2800 mah when fully charged. Just like Ranman suggested, discharge the pack and put them on a tray for a few days ( deadshorting the batt individually) , followed this method i was able to bring back my old 3300 to peak about 9.3+- and had about 3100-3200 in the batt..

lee82gx

iTrader: (1)

Tag:
forgive the obvious ignorance but i wanted to be sure:
Were u suggesting the Nicad(dead shorting 0V) tray or 1.2V-cut off try?
how long did the revive last?

Randy Caster

iTrader: (47)

I saved the money on a discharge tray, and just soldered a wire from the positive to negitive terminal on the battery

lee82gx

iTrader: (1)

Right,dead short it is.
i have to discharge the cells to 0.9V first right?

Randy Caster

iTrader: (47)

Whatever the lowest voltage you can get is, discharge it to that, otherwise the cells will get real hot when dead shorting them, and may cause more damage than good.

lee82gx

iTrader: (1)

Ok.thanks.i think i'll parallel a coupla resistors and then discharge it that way
and then put on dead shorting wires.
thanks.

disaster999

iTrader: (1)

ive always been told all my live that its a bad idea to dead short nimh batteries! you guys really sure that its a good idea to dead short nimh?

and just to make things clear here...the pack that is giving me problems is sanyo 3000 matched by smc

Randy Caster

iTrader: (47)

I've never done NiMH personally, but Tag seemed to have good results...

disaster999

iTrader: (1)

guess ill wait for more responds and more ppl to agree with Tag then

lee82gx

iTrader: (1)

i wouldnt do it to new cells,but for those dilapidated ones i wouldnt mind trying just for the heck of it.
doesnt really require a lot of money too.
another thing:
it might be a good idea to zap ur old sanyo's disaster999.