29 May
1998
29 May
'98
2:25 a.m.
On May 29, 6:53, Joe wrote:
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.
Then put the cell through a full-charge/deep-discharge/full-charge cycle.
I've resurrected quite a few NiCds with my 24V bench PSU and a 50,000mfd
30V electrolytic.
BTW, inside a lot of laptop batteries, you'll find a small metal box in
series with the cells. Don't throw it away; it's a thermal cutout intended
to prevent excessive current flow.
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
29 May
29 May
3:12 a.m.
The problem is, the battery pack for this computer is Nickel Metal
Hydride, not NiCad. Is there any process for "zapping" a NiMH
battery like there is for NiCad? I've had good success with NiCad,
but don't know what to do with the NiMH packs that are showing up in
the "newer" old laptops.
You could also rebuild the battery pack with NiMH cells. Would it be
possible to use NiCad with the same voltage/current specs? The battery
charger might not work?
By the way, http://www.toshiba.com has a plethora of information about
their old laptops. Some of the models, but not this one (T2200SX),
have complete manuals downloadable. There are also diagnostic and
setup disks.
Dave
Pete Turnbull wrote:
On May 29, 6:53, Joe wrote:
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.
Then put the cell through a full-charge/deep-discharge/full-charge cycle.
I've resurrected quite a few NiCds with my 24V bench PSU and a 50,000mfd
30V electrolytic.
BTW, inside a lot of laptop batteries, you'll find a small metal box in
series with the cells. Don't throw it away; it's a thermal cutout intended
to prevent excessive current flow.
--
Pete Peter Turnbull
Dept. of Computer Science
University of York 
3:35 a.m.
At 08:12 AM 5/29/98 -0700, you wrote:
The problem is, the battery pack for this computer is
Nickel Metal
Hydride, not NiCad. Is there any process for "zapping" a NiMH
battery like there is for NiCad? I've had good success with NiCad,
but don't know what to do with the NiMH packs that are showing up in
the "newer" old laptops.
You could also rebuild the battery pack with NiMH cells. Would it be
possible to use NiCad with the same voltage/current specs? The battery
charger might not work?
The battery manufacturers say that the batteries and chargers aren't
interchangeable. A good battery rebuilder should be able to replace the
original NiMH cells with new ones.
Joe
7:01 a.m.
Big snip
all that popping the cells with mega uF cap. That is very short term
solution and risky. Runs chances of explosion.
Best way is to get that pack rebuilt or new one. Cells themselves is
most expensive part of whole thing.
I priced several packs when I was reearching into rebuilding or new
packs. Cost difference is not that remarkable between rebuilt and
new packs even generic ones.
And you won't know which pack is very easy to rebuild until broken
open. Worst pack I tried to do rebuild on was LTE 386s/20. It has a
strange mini circuit board that govern fast/trickling mode only with
pack's 2 terminals also serving as same point for computer power form
battery. That failed after 1 fast charge mode. It now stuck at
trickling mode, takes 3 days to charge a 1700mAh 19.2V pack.
Jason D.
email: jpero(a)cgo.wave.ca
Pero, Jason D.
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.
8:16 a.m.
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ard＠p850ug1.demon.co.uk -
djenner＠halcyon.com -
jpero＠mail.cgo.wave.ca -
pete＠dunnington.u-net.com -
rigdonj＠intellistar.net