"William Sommerwerck" wrote in message
...
"Jeff Liebermann" wrote in message
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Ni-Cd cells like to be fully discharged every once in a while --
but not in a battery of series cells.

It's not just NiCd batteries, but all batteries.

Not as far as I know. Some lead-acid cells can be permanently damaged if
run down to zero even once. This happened to a Sony Discman battery that
was accidentally discharged slowly, over a period of about a week. It was
dead, dead, dead, and would not take a charge.

With total discharge, sulphation can set in that quickly.

There's various methods for reviving sulphated cells, but you have to act
fast or the sulphate steals a big chunk of capacity.

And as already mentioned, most SLA become marginal at best if discharged
below about 11V.