Google is your friend:
good temperature working range (-20°C to 70°C). For my American Friends that is -4 f to 158 f.
I don't think I'd go to 70 C myself.
https://upcommons.upc.edu/bitstream/handle/2099.1/26410/David_Balaguer.pdf?sequence=1&isAllowed=yJoeChiOhki wrote:
I'm curious to see how they do with charging in high temp areas, as heat + lithium ferrophosphate (What LiFePO stands for) = Bad and on most lithium battery powered equipment it will stop charging if they get too warm. My guess is if the ambient temperatures go past a certain point (Greater than 80 degrees is my guess), you may not be able to fully recharge the battery until it cools off (As part of the protection mechanism on the battery).