"Jeff Liebermann" wrote in message
...

100 flashes does seem like an almost fully charged battery.

But it isn't, of course. The voltage was at the nominal 1.25V when I
started, but this is well below the end-of-charge voltage for NiMH cells.


However, with such an intermittent load, it would have been nice if you
had a more controlled and more measurable way to test charge level.
If what you say is true, then you may be correct that there's no
self-discharge for a *NEW* NiMH battery. I'm wondering if it might be
a phenomenon that appears later as the battery is used. I'll run my
little discharge test when I have time and get my computer back home.

It was "scientific" in the sense of mimicking photographic use. 100+
full-power shots in a half hour, three at a time, is fairly extreme use.


Incidentally, several people mentioned that you cannot use the
open-circuit voltage as an indication of state of charge. I agree.

Of course. That's one of the problems with nicad and NiMH cells.

However, the fact that the cells read about 1.25V showed they WERE NOT fully
charged. But despite having sat for two years, they were able to give 100+
full-power shots. The point is that their were perfectly usable without
having to be recharged. This contradicts belief that NiMH cells rapidly
self-discharge. (Rates of 1% or more per day are stated.)

I might disable the flash's auto-shutoff and let the cells run down to 1.0V,
then see whether it can still fire more than once. (I have no desire to keep
popping the flash.)

PS: Sanyo says their current eneloop cells (rated at 1500 charge cycles)
will hold as much of 75% of their charge for 3 years.