Re: 1.5 v batteries - to buy ?

[Larry Cartwright <exit60@CABLESPEED.COM>]

Bernard Cleyet wrote:
> " The 1.5 volt version has a rather short shelf life because
> the parallel cells tend to discharge each other."
> This does puzzle me.  How does one large primary cell differ from two
> smaller wired in parallel?  Manufacturing variation, different temp.,
> etc. that results in diff. EMF's???

I don't have time for a reading/research project at the moment, but I
believe the phenomenon might have something to do with the following:

(1)  The 4 energy cells are not going to have exactly the same internal
R, and the one with the lowest R is going to dissipate a small amount of
power from each of the others.

(2)  As current flows between the cells, there will be temperature
changes which affect the R of each of the 4 cells.

If you stumble upon 4 cells with *exactly* the same R at the ambient T,
then there would be no mutual discharge, n'est-ce pas?

Best wishes,

Larry

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Larry Cartwright               Retired Physics Teacher
<exit60@cablespeed.com>        Charlotte MI 48813 USA
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"Information is not knowledge,
 knowledge is not wisdom,
 and wisdom is not foresight.
 Each grows out of the other and we need them all."
                                    (Arthur C. Clarke)
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