Peter Crosland wrote:

As regards 'memory' with Ni-Cads I stick by my view. It was never a
problem in normal use.

The problem with, and always has been, with Ni-Cad cells is that they do
develope memory unless you discharge them fully and then recharge them. The
problem with them is that people seldom do this and indeed often leave them
on charge day after day.

If you read up on the "memory effect" you will find that it is very
rare indeed. It only occurs when a NiCad is repeatedly charged and
discharged in *exactly* the same way (i.e. both times and levels). It
was discovered in NiCads used on satellites where the cycling was very
regular indeed.

Thus "memory effect" is very, very unikely indeed to be seen in any
domestic use of NiCad cells.

The only sensible reasons that I can think of for discharging before
recharging a-

To guarantee they are fully discharged before applying a full
charge which would otherwise overcharge them. A good
"intelligent" charger shouldn't need this.

To try and "even up" cells used in series so that all cells will
start completely discharged when charging them. However charging
cells in series is best avoided if you can. Discharging cells in
series completely is a *very* bad idea because the weakest cells
will get reverse charged towards the end of the discharge and
this does them no good at all.


--
Chris Green