NTLK Re: Batts in the freezer

From: Stainless Steel Rat (ratinox@peorth.gweep.net)
Date: Tue Jul 04 2000 - 22:45:47 CDT

* Ben Doughney <ben_d@clear.net.nz> on Tue, 04 Jul 2000
| I was told by someone that you can get rid of the NiCad memory by putting
| batteries in the freezer. Is this true?

Well, no, because "memory" is a myth. It doesn't occour except in sintered
plate nickel-cadmium cells of a type used in early telecommunications
satellites (Telstar and such), and then only under exacting laboratory
conditions. Modern cadmium paste cells simply do not suffer from charge
cycle memory. What is frequently called "memory" is in fact permanent
physical damage to the cell caused by either overcharging or
overdischarging. Once such damage occours the cell is ruined; there is no
way to fix the damage. Freezing it will not help, and could cause more

Under normal use, cadmium crystals will form within the paste; this reduces
maximum charge capacity of the cell. THIS IS NORMAL. It is not memory; it
is the normal life cycle of a NiCd cell. *OCCASIONAL* deep discharge of
NiCd cells will break up these crystaline deposits somewhat, restoring some
of the capacity of the cell. But it is perfectly normal for the maximum
charge of a NiCd cell to gradually decline over time.

Rat <ratinox@peorth.gweep.net>    \ Warning: pregnant women, the elderly, and
Minion of Nathan - Nathan says Hi! \ children under 10 should avoid prolonged
PGP Key: at a key server near you!  \ exposure to Happy Fun Ball.
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