29 May
1998
29 May
'98
3:18 a.m.
At 02:25 PM 5/29/98 GMT, you wrote:
On May 29, 6:53, Joe wrote:
The problem with this is that the crystal growth puctures the separator
membrain between the two electrodes. That usually usually ruins the cells.
They may last for a short while but that's all. High current can also
cause the cell vents to open and then the electrolyte leaks out and ruins
what ever the batteries are in. Replacement batteries are cheap, it's not
worth the risk IMO.
Joe
Cord wrote:
>I just picked up an older style laptop that I
need some hlp on. It is
>a Toshiba T2200SX laptop.
>1) I need a battery for this unit. I have the
power supply, but the
>battery with it won't charge.
Your chances of finding another battery are slim.
Even if you find one
it will be old and probably won't last long. My suggestion is to take it
to one of the battery places that rebuild batteries and have them replace
the cells in your old battery.
If you can take the battery pack apart (separate it into single cells) in
such a way that it could be re-assembled, all is not lost.
The usual problem with NiCds is that internal crystal growth makes short
circuits; the battery will show virtually 0V. If you force a sufficiently
high current through the cell, it will often remove the short. However,
the current needs to be very high, and has to be of short duration to avoid
other damage.
The way I do it, is to charge a large electrolytic capacitor up to 20V -
30V, connect one side to one end of a cell with a short thick wire, and
touch ("flash") the other side to the other end with another short thick
wire. The spark is usually fairly dramatic, so it's best to touch the wire
to the terminals and not the case (lest the arc burn through it), and use
eye protection. Repeat as required until the cell shows some reasonable
voltage.