Re: NiCD or LiFeS2 for low temp?

[EMAIL PROTECTED] (David Harper) wrote in 
news:[EMAIL PROTECTED]:

> I'm debating on whether or not to use NiCD cells (provided with the
> radio that is using the cells) or substituting these cells with
> Lithium-Iron Disulfide cells (AA provided by Energizer) for a high
> altitude application where the enclosure temperature could easily drop
> below freezing.  From the spec sheet on Li/FeS2 cells, they can
> operate down to -40C.  However I have not found concrete information
> on the low temperature limitations of NiCD cells.  Does anyone have
> experience or information that they can provide?
> 
> In addition, I was wondering if both cells would be able to provide
> the needed 700mA while at low temperature (say, -20C)?  The discharge
> profile will be approximately 16 second at 700mA, with 180 seconds at
> 70 mA in between the 700mA pulses.  This profile will last for about 3
> hours.
> 
> Any information that can be provided would be greatly appreciated!
> 
> Thanks in advance!
> Dave
> 

Panasonic implies that capacity of NiCD is not significantly affected 
down to -20C.

http://www.panasonic.com/industrial/battery/oem/images/pdf/Panasonic_NiCd
_Precautions.pdf

Tim

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