Msg: 2692 *Conference*

06-10-92 08:24:55

From: TRACY ALLEN

To : RICK LOPES

Subj: REPLY TO MSG #2676 (LAPTOP NICAD BATTERY PACKS)

Dear Rick,
  That's a bundle of questions!  I'm a lot more familiar with the technical
side of gel-cells than I am with niCADs. But I'll give it a try.  I think the
modern generation of NiCADs are a lot more tolerant than the ones of just a
couple of years ago when all the lore about charging and discharging built up.
But it is still true, nicads do best in applications where they go through deep
discharge cycles, because of the memory effect.  They thrive in applications
like cordless tools.  But computers so often plugged run off the wall, so to
speak, that the nicacs don't get the deep cycling.  When you receive nicads,
they are usually discharged and you have to charge them up.  I'm not sure what
is the best way to store them.  Storing them completely dicharged goes against
the grain for me, because that is the worst thing you could do for a gel-cell.
I think that however you store them, charged or not, you should store them in a
_cool, dry_ place.  Not freezing, but the cooler the better.  The charge will
gradually leak off the battery.  Then when you put the bazttery in service, run
it through a couple of full cycles to restore its vigor.  I think that nicads
have a life of around 1000 full cycles.  They give out gradually, although if
they are mistreated (overcharged, stored at high temperat;ures)  they can
develop sudden pathologies due to internal short circuits or something.  Radio
Shack sells a nice little manual on care and feeding of batteries--you might
find it an interesting browse when you're in a Shack--you might even buy it!
    
  On the Toshiba question, I'd follow the guidelines in the Toshiba manual to
the letter.  Sometimes the battery pack is used as electrical "filtering" and
it could be harmful to the machine to run without it.  The manual would say so
if that's the case.
  -- Tracy