If I hear correctly the Pyra battery will be cross compatible to Pandora?
Pandoras battery could be used if you add padding... but not sure if that does make sense.
I plan on doing it for the reason fusion_power mentioned. I still don't use my "spare" Pandora battery, so I may carry it with my Pyra if I find I run out of power during the day if I don't charge it. I don't care if I have to pad it to make it work. Maybe I will print an adaptor.Would have increased the usability and value of both devices, since Pandora owners would already have a spare battery then for Pyra.