On 13:27 17 Nov 2020, T i m said:
On Tue, 17 Nov 2020 12:13:56 GMT, Pamela wrote:


Now, on the AAA's it states the 'Standard charge is 80mA for 16
hours' and I presume by that they mean '... to get the best life
/ cycles out of the cell'.

snip

Surely that has been incorrectly taken from the standard advice to
slow charge a new battery for a long time (say 8 hours) to ensure
all cells reach max charge. Hard to see why it's applied to
single cells.

Same thing though isn't it Pamela? A battery only (typically)
being a combination of single cells wired in series and so the
current though the battery = the current though each cell?

If one cell in a battery (where the cells are in series not parallel)
is weaker than the others then it will overload during charge sooner. A
very low charge rate, say C/10, doesn't cause an NIMH cell to vent --
so it can be applied for much longer while all cells reach full charge.

Similarly on discharge to a low state, albeit not at issue here, a weak
cell in a battery can be forced into reverse polarity by the other
cells discharging normally -- as I have seen.

Anyway, the bottom line seems to be that a single NIMH cell doesn't
actually need a long low-current conditioning charge.