Lithium E2 battery problem

[Jim]

I have been using Energizer Lithium E2 AAA cells to power microwatt
telemetry transmitters for a couple of years. These were my choice not only
for their long life, but also because they are suppose to be able to sustain
their voltage in extreme hot and cold temps.

I have run into an issue on several occasions where my transmitters stop
working, and when recovered, the battery is not dead , but instead has a
voltage far above 1.5 volts, sometimes double that. What could be causing
this? I could understand if they went dead because of current draw or
whatever, but this isn't the case.

This problem has mortally damaged several of my transmitters.

I use 5 minute epoxy to attach the battery/transmitter combo, and have
wondered if I have been covering up the battery's vent holes or something
like this.

Can anyone supply me with any ideas on this problem, or suggest an
alternative way around this?

Thanks
Jim

 

[Lostgallifreyan]

"Jim" <jbasi@cfw.com> wrote in news:eb007$49f507c4$d80c3a27$3168@NAXS.COM:

I have been using Energizer Lithium E2 AAA cells to power microwatt
telemetry transmitters for a couple of years. These were my choice not
only for their long life, but also because they are suppose to be able
to sustain their voltage in extreme hot and cold temps.

I have run into an issue on several occasions where my transmitters stop
working, and when recovered, the battery is not dead , but instead has a
voltage far above 1.5 volts, sometimes double that. What could be
causing this? I could understand if they went dead because of current
draw or whatever, but this isn't the case.

This problem has mortally damaged several of my transmitters.

I use 5 minute epoxy to attach the battery/transmitter combo, and have
wondered if I have been covering up the battery's vent holes or
something like this.

Can anyone supply me with any ideas on this problem, or suggest an
alternative way around this?

Thanks
Jim

That's worth taking up with the maker. First establish if the batteries
really came from them. It's possible that Chinese batteries might be resold
having been sold as counterfeit Energisers, having been made from materials
with poor control of chemical purity. It sounds like the battery chemistry
has somehow reverted to the kind of voltage normally found in lithium cells
not designed specifically for the lower voltage. Impurities might cause that.
Covering vent holes might be a cause, but if more gas were produced the
battery might have either exploded, or forced a path past the epoxy, so it's
worth looking to see if forced outgassing can be detected. Consider the
temperature too, they're ok with cold, but if they ran hot there could be
rapid degradation.

As you're fitting batteries outside a small transmitter device, consider
changing the device so it runs on 3V or so safely, as you can take advantage
of cheaper and more enedgy-dense standard lithium batteries, including
rechargeable Li-ion. That way even if a battery fails it won't destroy your
gear with overvoltage.

 

[John S]

On 27 Apr 10:16, Lostgallifreyan wrote:

"Jim" <jbasi@cfw.com> wrote in

I have been using Energizer Lithium E2 AAA cells to power
microwatt telemetry transmitters for a couple of years.
These were my choice not only for their long life, but also
because they are suppose to be able to sustain their voltage
in extreme hot and cold temps.

I have run into an issue on several occasions where my
transmitters stop working, and when recovered, the battery is
not dead , but instead has a voltage far above 1.5 volts,
sometimes double that. What could be causing this? I could
understand if they went dead because of current draw or
whatever, but this isn't the case.

This problem has mortally damaged several of my transmitters.

I use 5 minute epoxy to attach the battery/transmitter combo,
and have wondered if I have been covering up the battery's
vent holes or something like this.

Can anyone supply me with any ideas on this problem, or
suggest an alternative way around this?

Thanks
Jim


That's worth taking up with the maker. First establish if the
batteries really came from them. It's possible that Chinese
batteries might be resold having been sold as counterfeit
Energisers, having been made from materials with poor control
of chemical purity. It sounds like the battery chemistry has
somehow reverted to the kind of voltage normally found in
lithium cells not designed specifically for the lower voltage.
Impurities might cause that. Covering vent holes might be a
cause, but if more gas were produced the battery might have
either exploded, or forced a path past the epoxy, so it's
worth looking to see if forced outgassing can be detected.
Consider the temperature too, they're ok with cold, but if
they ran hot there could be rapid degradation.

As you're fitting batteries outside a small transmitter
device, consider changing the device so it runs on 3V or so
safely, as you can take advantage of cheaper and more
enedgy-dense standard lithium batteries, including
rechargeable Li-ion. That way even if a battery fails it won't
destroy your gear with overvoltage.

Whenever I have seen this I guessed that the manufacturer was
trying to cram in more charge than their battery chemistry
properly allowed.

ISTR encountering this more on basic Chinese zinc
carbon/chloride cells than on Chinese alkaline cells.