> > Say that two alcaline penlight cells have a capacity of 3000ma/h.
> > You don't want that 3A over one hour but only 0,5ma during X hours.
> > 3000/0,5 = 6000 (x 1 hour). Which is ca. 250 days, or ca 10 month,
> > before the cells are empty. And empty is about  1.3v each.

Thanks for the input, but this much I know.

>While that makes "math sense" in the real world that just isn't that useful
>a technique. The reason is the "capacity" of a battery is dependant on the
>load. Some batteries are far better at handling smaller loads over long
>periods of time then others "i.e. alkaline vs. nicad).

And this much I know too, but I suspect Herbert knew that when he replied...

>Therefore, while a battery may state 1000mAh, that does NOT mean it can
>supply 1mA for 1000 hours. What it means is usually the bit of information
>that's left out of a quick spec: the load current where you get that
>rating.

This is the hook, eh?  For example, duracell (IIRC) specs their cheap-o AA
cells at ~1200 mAH @ 1A, 1600 mAH @ 10 mA, etc., but that doesn't
help down below 1 mA.

>The ONLY ways to realistically get good numbers is either to spec the
>SPECIFIC battery (from the manufacturer) or to do real world testing.
>
>Oh, and on top of all of this, the capacity of a battery is dependant on
>more then just current, most batteries are VERY dependant on temperature,
>age is also a very important figure, as is number of discharge cycles. TTYL

Sigh.  Well, maybe I just need to apply my brainpower and write my own
little application.

With my soon-to-be-shipped free copy of VB.net!

Mike H.

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