"Christian McArdle" wrote in message
et...
How does the capacity of a Duracell-brand AA cell (Duracell ordinary
or Duracell ultra) compare to one of the high-capacity NiMH cells
(eg
2100 mAh)?

It depends on current drain. Alkalines are vastly superior in low
drain
appliances, such as clocks or smoke alarms, to the point where NiMH
would be
useless. In high drain appliances, such as DVD players with integral
screens, the alkaline would be in chocolate teapot territory.

That's the first time I've heard of that, so I had to google it.
http://itre.cis.upenn.edu/~myl/langu...es/001333.html
I've heard the teats on a boarhog one and fish needs a bicycle, but not
a chocolate anything. Seems like most of the younger folk haven't even
seen a fireplace so that one's kind of nonsensical to the average joe.
And then there's the average American, who drinks more coffee than tea,
however that depends a lot nowadays, since there seems to be a kick in
tea consumption now that they are promoting its health benefits -
antioxidants, etc. But then most tea is bought in teabags, so teapots
seem to be getting rare...

But I'd _love_ to have a chocolate teapot, it'd be very useful to me, to
nosh on!

The changeover point where one is better than the other is very much
in the
direction of low drain. Any appliance that uses remotely much
electricity
will much prefer NiMH, even with the lower nominal voltage. In fact,
the
alkaline will produce a lower voltage for most of its discharge cycle
in any
medium to high usage application. 1.5V is only available when the
battery is
totally fresh and not being discharged to any extent. Any depletion in
the
cell, or any current drain will result in rapid voltage drop, often
even to
0.8V or so. This doesn't happen with NiMH. They can produce almost
full
voltage until very nearly depleted, even at high current levels.

Christian.