"Jeff Liebermann" wrote in message
...
On Wed, 1 Jun 2011 10:31:48 -0700, "William Sommerwerck"
wrote:

The operative word here is STAX -- as in high-voltage electrostatic
earphones. I never measured the drain, but neither set of cells
lasted much more than four hours.

$2,000 for earphones and you're worrying about the price of
rechargeable batteries? Argh.

No, they were more like $350. I said earphones, not headphones.


There seems to be two amps. One with tubes and the other presumably
IC's.
http://www.stax.co.jp/Export/ExportProducts.html
55 watts and 46 watts power consumption from an internal 117VAC power
supply. No batteries in sight. Wrong unit?

Wrong units. This is a pocket-sized transformerless energizer that runs off
two AA cells. It works with a tiny pair of electrostatic earphones.


We still don't have a rational answer as to why some people don't have
problems with rapid self-discharge.

Oh, that's easy. How many charge cycles would you guess you get on a
set of NiMH before they're ready to recycle? You probably don't know
and neither does Joe Sixpack. I don't even know because nobody is
counting. So, Joe Sixpack may get 2 years of service out his NiMH
battery pack, but has only charged it perhaps 20 times before it died.
I vaguely know someone that maintains TV camera battery packs for one
of the major networks. Current technology is Li-Ion but in the not so
distant past, it was NiMH and NiCd. He keeps meticulous records. I
must admit that I wasn't paying attention when he showed me the
numbers, but it seemed to me that even for identical battery packs,
the numbers were almost random. Some would last on a few charge
cycles, while other would last seemingly forever. He attributed this
mostly to depth of charge and storage temperature. Even the best
battery, stored hot, will die prematurely. This is a known problem
with Li-Ion, but I'm not sure if storage temperature has any effect on
NiMH. Mine are all in the fridge, just in case. Depth of charge is
the biggie. A battery that is only discharged to perhaps 75% of full
charge, can be charge cycled many more times than one that is fully
discharged before recharging. However, if the charger is too
aggressive, a battery that's discharged to 75% might be overcharged,
while the one that's fully discharged is less likely to be
overcharged.

That's extremely useful information, but I'm still not sure it answers the
question -- unless you're suggesting that the people who have problems with
rapid self-discharge have damaged their cells.