While debugging a strange battery failure in a manufacturing process, [Josh] discovered a new (to us) LiPo battery failure ... each in a different initial charge, into a plastic bag and tortured ...

Lithium-ion has proven so successful due, in part, to its very high energy density, lack of the “memory effect” (where cells become more difficult to charge over time) unlike previous battery ...

But LiPo cells must not be charged in freezing ... the battery with an integrated heater and preheat the battery to a safe charging temperature as well. So, just like everything with electronics ...