15 Nov
2002
15 Nov
'02
9 p.m.
I'm lucky enough to have picked up an old marine battery charger for $5 at a
yard sale last year. It's good for 6v-60v. with voltage and amperage controls
as well as a 10A limiter switch. As I say, I've got about a dozen Ni-Cads and
about a dozen laptops, none of which, except an old NEC, which has a
working battery. Also a Commodore 386 that I've been unable to find a power
supply for,( has a strange 5pin mini-din plug, made by Sanyo I believe
also labelled as a Zeus, and Everex). I have to decide which laps I want to
use as carry-abouts and possibly rebuild them myself as even the rebuilders
charge about US$60 ($6000 Canadian ? :^} ) And if I have to take them apart
anyways I may as well get my own replacement cells and use duct-tape.
Thanks all. There's also a PD program called "deepdran.exe" (deepdrain)
which I can use to exercise the batteries after, if it's successfull. Worth a try.
Lawrence
Rather you than me! A car battery can provide a rediculously high current
(at least 500A), and the risk of the NiCd exploding is pretty high as a
result. I prefer to use a current limited bench PSU (10A max), and even
then to just 'tap' the contact.
lgwalker(a)mts.net
bigwalk_ca(a)yahoo.com
What really happens is that minute 'hairs' grow from terminal to
terminal in the cell, effectively shorting it out. To remove them
requires a flash of current to 'burn' them out. Either a high current
source (10A or more) or a large capacitor discharged into the cell does
the job.
I have used an automobile battery to "zap" them. Shorting a NiCad to an auto battery for just a split second
usually burns out the
whiskers. HOEVER the fix usually doesn't last long. One of things that
Agreed. As you seid below, the NiCds will work long enough to prove that
the rest of the device is working and that it's worth investing in a new
set of NiCd cells.
-tony