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How dead can a battery get?

  • Thread starter Thomas A. Horsley
  • Start date
T

Thomas A. Horsley

Jan 1, 1970
0
As part of my continuing hacking on my silly cell phone ring notifier
(http://home.att.net/~Tom.Horsley/phonetale/markII.html) I was curious how
long the batteries would last in the first box I built (4 AA duracell's in
series).

Turns out it was about a month, and I just pulled them out and stuck
a voltmeter on them. Three of them read about .7 or .8 volts (seems
believable), but one of them read -1 volt (or maybe it was -1 millivolt
and I didn't notice the scale change on the display).

Is that a normal thing to see in a really dead battery? I never
expected the voltage to go negative on me. Maybe I could turn it
around and make it last longer :).
--email: [email protected] icbm: Delray Beach, FL |
<URL:http://home.att.net/~Tom.Horsley> Free Software and Politics <<==+
 
J

John Popelish

Jan 1, 1970
0
Thomas A. Horsley said:
As part of my continuing hacking on my silly cell phone ring notifier
(http://home.att.net/~Tom.Horsley/phonetale/markII.html) I was curious how
long the batteries would last in the first box I built (4 AA duracell's in
series).

Turns out it was about a month, and I just pulled them out and stuck
a voltmeter on them. Three of them read about .7 or .8 volts (seems
believable), but one of them read -1 volt (or maybe it was -1 millivolt
and I didn't notice the scale change on the display).

Is that a normal thing to see in a really dead battery? I never
expected the voltage to go negative on me. Maybe I could turn it
around and make it last longer :).

The first cell to go dead will be reverse charged by current from the
remaining good (or better) cells.
 
This is not related to the dead battery but I live in Taiwan and we
have the phone things you're talking about. A little cell phone cradle
that lights up when your cell phone rings. Usually they are quite goofy
looking like a hand or something like that. If your interested I can
send you one.
Raul
 
T

Tom Horsley

Jan 1, 1970
0
This is not related to the dead battery but I live in Taiwan and we
have the phone things you're talking about. A little cell phone cradle
that lights up when your cell phone rings. Usually they are quite goofy
looking like a hand or something like that. If your interested I can
send you one.

Actually, I have one of the lights (it is built into a pen, not in
a cradle), but it lights up every time the phone is communicating with
the cell tower, which as near as I can tell happens at least once
an hour (no doubt the conspiracy nuts will say it is sending back all
the compressed audio it has recorded during the last hour to home base
in area 51).

Anyway, I'm having too much fun wasting vast quantities of time on
this gadget to want a commercila solution at this point :). Thanks
for the offer though.
 
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