Anelok: look what the cat brought in !

Werner Almesberger werner at almesberger.net
Tue Mar 17 18:15:11 UTC 2015


It's a dead battery !

http://downloads.qi-hardware.com/people/werner/anelok/tmp/cr2032-1047h.png

1047 hours is pretty close to the theoretical 1077 I calculated
from the nominal capacity Sony publish and the guesstimated age
of the cell.

I also checked the resistor: my meter reads 14.886 kOhm at about
32 C. That's within 1% of the nominal value of 15 kOhm.

So the battery did perform pretty much according to expectations.
What I didn't expect was that it would drop relatively quickly to
2.8 V and make its stance there, instead of remaining closer to
2.9 V for a while.

And I now also have a clearer idea of how temperature affects
these cells.

Now that the multimeter is free again, I can finally begin to
test operation on battery power. I already reworked one of my
boards and it is still happy, at least on USB power.

As a reminder, this is the the rework plan:
http://downloads.qi-hardware.com/people/werner/anelok/tmp/boost-rework.pdf

This is what the cuts look like:
http://downloads.qi-hardware.com/people/werner/anelok/tmp/boost-rework-cuts.jpg

This time I used my Dremel with a small endmill, 12 mil diameter,
and the result is much cleaner than what I normally get with a
knife.

These are the cables on the top side (and a lot of flux):
http://downloads.qi-hardware.com/people/werner/anelok/tmp/boost-rework-cables.jpg

- Werner



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