You’re out doing some holiday shopping when you see your battery is almost empty. Wait, it was at 100% this morning, and you barely touched the thing all day! What could you have done wrong to wear it down so quickly? Could it be that cold winter weather?

Ever left your phone in the car on a freezing winter day? “Yeah, but I just needed to pop into the store for a loaf of bread!” It’s what you tell yourself, but then you quickly see that the poor thing works super slowly after that or even shuts down completely for some time. Why is it so?