iFixit says that heat is the biggest killer of batteries and therefore you should avoid placing your laptop on an insulator like a pillow. Why? Assume it’s only exposed to the 40 something Celsius of a laptop at heavy load and not extreme heat that can melt off the casing or something, what about heating it up causes it to fail sooner?
Plugging the device in all the time can also reduce battery lifespan. Why is *that*? I’d have imagined that once on wall power, the device can afford to either use the battery sparingly or not at all, depending on if the charger is powerful enough.
What are the chemical processes that take place to make these two things the biggest reasons batteries fail?