Re: Arisian Ellipsoidal Polychromatic Lens w/MultiJewel Array!

On 9 Apr 2008 22:33:05 -0400, "Keith F. Lynch" <kfl@[EMAIL PROTECTED]
>
wrote:

>Karl Johanson <karljohanson@[EMAIL PROTECTED]
> wrote:
>> Some years ago Dear Abby answered a letter wondering why watch
>> batteries last years, where as hearing aid batteries last weeks.
>> She asked some expert who claimed that heating aids use
>> significantly more power.
>
>Sounds plausible.  Watches use so little power that the battery
>doesn't so much run out of power as out of shelf life.  Hearing
>aids obviously have to produce fairly loud sounds, which takes a
>lot of power.
>
>My question is whether watch batteries and hearing aid batteries are
>pretty much the same kind of thing.  Are they of similar size and
>similar power capacity?  I wouldn't be surprised to learn that hearing
>aid batteries are much more expensive and are made deliberately
>incompatible in subtle ways so that people can't just use cheaper
>watch batteries in their hearing aids, but I don't actually know.

From Wikipedia (http://en.wikipedia.org/wiki/Zinc-air_battery):

"Zinc-air batteries (non-rechargeable), and zinc-air fuel cells,
(mechanically-rechargeable) are electro-chemical batteries powered by
the oxidation of zinc with oxygen from the air. These batteries have
high energy densities and are relatively inexpensive to produce. They
are used in hearing aids and in experimental electric vehicles. "

and

"Zinc-air batteries have properties of fuel cells as well as
batteries: the zinc is the fuel, the rate of the reaction can be
controlled by controlling the air flow, and used zinc/electrolyte
paste can be removed from the cell and replaced with fresh paste"