Fish wrote:
My major concern was that of secondary battery failure due to low
temps. It's not like we even get the opportunity to reach such heights
where I fly, but, should the opportunity arise to explore some wave,
i'd hate to see the little 9V backup battery on the ILEC, decide to
have a rest when it was needed most.
Does anyone have any clues on the behaviour of lithium batts at lo
temps?

Yes, they show significantly less degradation at cold temperatures than
alkaline cells or lead acid batteries. They are used in the Perlan
project for precisely this reason...

Marc