"Phil Allison" wrote in message
...

"William Sommer****** is Full of **** "

Phil Allison is a foul-mouthed shmuck.

By the way, in German "shmuck" means "jewelry" or "adornment". Billy Wilder
gets a funny gag out of this in "One, Two, Three".


100 is for a full-power flash.

The flash energy input is probably about 20 joules, ie 330uF
and 350V. Allowing 5 joules for losses, the energy required for
100 flashes is 2500 joules.

The losses are probably greater than that. When I left the flash running,
without firing it, I was surprised that it conked out after about two hours.

I suspect this flash provides more than 20Ws output. But the specs are
silent on this.


A fully charged, 2500mAH NiMH has a capacity of 11,000 joules
(1.2 x 2.5 x 3600). Four of them have a capacity of 44,000 joules.
So, your "magic" Sanyo cells had under 6% of normal capacity.

I can't argue with plausibly-chosen numbers, and I won't. However...

You're still missing the point. We have been told that NiMH cells lose
several percent of their capacity every week. (Let's say 3%, and assume it's
a linear loss, rather than exponential.) After 102 weeks, the cells should
have been dead, dead, dead. They were not. They had no trouble powering the
flash to its spec'd number of full-power flashes. What do you want, for
heaven's sake?

The point about "voltage creep" of nicads & NiMH cells was well-taken.
However, I measured the cells' voltages within about 15 seconds of shutting
off the flash. Furthermore, the under-load voltage is arguably not that
important if the DUT works as it's spec'd. Which this flash did.

Please note that I actually performed an experiment! I tested cells that
should have been useless. They were not. The statement that conventional
NiMH cells are generically incapable of holding a charge for extended
periods is simply NOT TRUE. Not because "I say so", but because I have
empirical evidence.

Yesterday I pulled out my Sunpak 622 Super, a "professional" potato-masher
flash. It has four 5500mAh NiMH C cells made by CTA, whoever that is. (They
came from Overstock.) The last time I charged them was about six months ago.
I flicked the power switch, and unit came to full power in 6 seconds.
Full-power recycling was 4 seconds -- not great, but not bad, either,
especially for "dead" cells..