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Old September 12th 06, 03:54 AM posted to rec.crafts.metalworking,rec.radio.amateur.homebrew,rec.radio.amateur.equipment
scrook scrook is offline
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First recorded activity by RadioBanter: Aug 2006
Posts: 5
Default Overheating AA batteries

Positive can/case is standard alkaline cell construction. The correct
question would be "has anyone ever seen a negative cased alkaline cell?"


"Mark Rand" wrote in message
...
On Sat, 09 Sep 2006 16:11:20 -0400, ken scharf
wrote:

bart wrote:
This evening the GF noticed that the remote control wasn't working &
was hot.
I pulled out the extremely hot AA batteries.
It looks like the spring contact in the remote control, on the
negative side had worn away the plastic covering on the side of the
battery & shorted the side metal battery casing to the negative
contact, thereby causing the overheating.
In my many years of battery dissection, I've never seen the side
casing of a battery being positive before!
These were "Golden Power" alkaline batteries, made in China.
They were the original batteries that came with the remote ( for a
Shaw digital cable box).
Anyone ever seen a positive case AA battery before, or is this a new (
dumb) idea?

I've seen many Alkaline batteries with the outside casing connected to
the 'tit' on top as the positive and the bottom flat connector was
insulated from the body of the battery. alkaline batteries have
different chemistry from carbon zinc resulting in an inverted
construction. This may actually be the norm, but in the larger sizes
the plastic outer wrap hides the details. Just looked at a DuraCell
"D" and it is of the inverted construction, but the insulation of the
battery bottom (-) terminal from the case of the battery is hidden
under the plastic wrapping.



Since it's the cathode that gets eaten in whichever reaction is used for
the
battery type, it might make sense to have the anode as the case.

I could have done with this 25 years ago when I got sent abroad for work
for
three of months and came back to find that the transistor radio batteries
had
leaked all over one of my (expensive) loudspeakers :-(

Mark Rand
RTFM