Zapping Laptop batteries

From: Mike Feher <n4fs_at_monmouth.com>
Date: Fri Nov 15 18:35:01 2002

HT stands for High Tension and LT for Low Tension (filaments). I have been
zapping NiCds for about 40 years and have a fairly decent success rate. If
it is not going to work you will know real soon. Sometimes a battery just
cannot be zapped at all, in other words regardless of the finite high
current that you momentarily put through it, it will still be a short. No
sense wasting time on those. Others will open up and even take a charge
during the zapping process. As mentioned before they need to be zapped
individually. Just about 2 weeks ago I was working on the battery pack in my
HP Cesium which was dead. Charging it externally at C/10 the terminal
voltage never came close to what it should have been. This package is
comprised of 20 1/2 size D cells. 7 of them were shorted. The date code was
1995 on the package, which I felt was not that old. I zapped the 7 cells and
they all came alive. Then I charged them and all looked good. Then I
discharged them at a 1 amp rate, the package is rated for 2.4 AH. I went
through this exercise about 4 or 5 times, charge, discharge. Worked every
time. I usually charged it during the night where I did not mind the long
time of 10 hours. After the last charge cycle I just let it sit for over a
week. That is usually when the bad ones show up. It still holds up fine and
seems to meet rated capacity. Each cell is less than 10 millivolts from each
other. I lucked out on this one as 1/2 Ds are not very common. There have
been others when I was not so fortunate. But since it is bad, one has
nothing to loose by trying. Regards - Mike




Mike B. Feher, N4FS
89 Arnold Blvd.
Howell NJ, 07731
(732) 901-9193
Received on Fri Nov 15 2002 - 18:35:01 GMT