Roy ,Tnx for your comments ; I'll do some tests with NiMH cells
using a 'Maha C777Plus' discharger/(pulse)charger and check capacity .
I'll repeat the discharge/charge process a few times to see whether capacity
changes.
I realise that automatic chargers charging at a high current might not
charge any cell to its maximum capacity,
that's why I shall also charge the cell at a lower rate using a LM317
constant current circuit.
with the Maha device the cell's capacity is indicated following the
completion of a discharge period from fully charged to a threshold of just
below 1 Volt
I knew that brand new cells only get their full capacity after having been
cycled a number of times.
BTW : NiCads and NiMHs I use regularly are kept in good condition by
constant trickle charging at a few mA
, again ,with a LM317 constant current circuit ,because specially NiMH cells
have a relatively high self-discharge rate.

Frank GM0CSZ / KN6WH

There are several reasons why NiMH cells might not do as well as they
should. One is that chargers will often shut down well before the cells
are fully charged. This is particularly common with new NiMH cells, until
they've been cycled a half dozen times or so. Another potential problem is
voltage depression, mistakenly called "memory". This can be cured by a
full discharge to 1.0 volt/cell then recharge. Cells also have less
capacity after long storage or a history of light use and recharge.
Several cycles are necessary to restore full capacity. And of course,
modern NiMH cells at 2500 mAh or more have a lot more capacity than
earlier ones which were as little as 1300 mAh or so -- if you did a
comparison some time ago, things have changed since. A number of fast
chargers don't charge cells to their full capacity. Finally, a substantial
portion of some cells' capacity originates in the marketing department --
tests I've run show the capacity of some to be pretty badly inflated
(Lenmar is a common brand that comes to mind). They do take some care and
feeding -- if it's too much of a hassle, alkaline cells are a solution.

Roy Lewallen, W7EL