[ELECTRON] Battery chemistry.

[Clive Mitchell]

Has anyone used the newish technology NiZn batteries that seem to be
available these days?  They are available in the common AA and AAA
sizes and seem to have an advantage over traditional Nickel Cadmium
and Nickel Metal Hydride cells in that they have a cell voltage of
about 1.6V which is maintained across a significant part of the
discharge curve.  This gives them the voltage advantage of alkaline
cells with the rechargeability of NiMh's.

I've just bought some from a Chinese source along with a suitable
charger.  The charging requirement is interesting in that you can't
trickle charge them, but require a charger that stops charging as soon
as the voltage across the cell rises to 1.9V .  This is apparently due
to the chemistry not facilitating recombination of gas inside the cell
resulting in venting if it is left on charge continuously.

The application I have in mind for the cells is with gallium nitride
technology LED strings that use 2AA cells as opposed to the preferred
3AA pack, since they often have a very much reduced performance with
conventional NiMh cells due to the lower 1.2V cell voltage.

-- 
Clive Mitchell