Dave Platt wrote:

My own experiences are otherwise. "Traditional" NiMH batteries I
have used, would tend to lose a substantial fraction of their charge
within a few weeks, and would be nearly "flat" after three months of
storage.

That's about right, if not pretty good. The discharge rate that Motorola
once claimed in an ancient phone manual I once had was 30% per week.

The problem seems to be worse with the higher-capacity cells... a 2600
or 2700 mAh classic-NiMH cell would lose charge at a faster rate
(both absolute and percent-per-day) than an 1800 or 2000 mAh cell of
the same brand.

In effect what they have done is traded off how long a charge lasts
versus hom huch that charge is. Unless you have the guts of a battery
hidden in a black hole, there is only so much room in the case.



In certain applications - e.g. in the camera or flash unit of a very
busy photographer - the high-capacity "classic" NiMH cells may be the
best choice. It doesn't matter very much if they lose 2% of their
charge per day, if you're going to be running 'em down within a week
anyhow.

For low-rate or standby applications, the new ultra-low-discharge
cells are wonderful. I keep two sets of six in my ham-radio "go-kit"
for my spare dual-band handheld radio... each set will run the radio
through two 8-hour shifts of typical operation, and giving the a brief
topping-up charge every six months seems to be all that's required.

That depends upon what power level you run the radio. I found that out in
the mid 1990's with the Ray-O-Vac rechargable alkelines. Everything I had
as except flashlights only worked for one or two charges before they
could not put out enough current to be of any use.

There were just some places that 1 watt would not open the local repeaters
even with an better quality rubber duck than the one that came with the
HT. Switching to higher power drew too much current. :-(

Geoff.



--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM