Re: AA Battery capacity tester- resistor & clock

Thanks to all- I might set up an excel *** to plot curves and do it
the way John suggests just for curiosity's sake.

And yes to Phil- 4 clocks- mounted on lexan. It looks so good I was
really disappointed when it didn't work as planned.

On Fri, 27 Jul 2007 13:11:14 -0500, "Anthony Fremont"
<anyone@xxxxxxxxxx> wrote:

-snip-
What you really need to do is to connect the 1R resistor in "parallel" with
the battery, not in series.

Aha! I can't find the post now to see if I misread- or he
mis-wrote. At any rate- that's the ticket.

-snip-
With that out of the way, I suspect that you can get an approximate capacity
by using the clock as described. Assuming that it stops when the battery
voltage drops to about .8V AND pretending that the voltage curve is linear.
You are averaging a 1A load over time, so if the clock stops at 1:30, you
could sorta say that the battery had 1500mAh charge.....sorta. ;-)

For my purposes this will work fine. I've found that usually when a
'set' of batteries goes bad, it really means *one* has bit the dust.
This will locate that one with a minimum of fuss.

Thanks again-
Jim
.