[throwaway64]

storing hot is what is detremental to lithium batteries, storing them cold increases lifetime

[jambalaya]

Should I store batteries I don't use in the fridge or freezer? I have a backup laptop battery for instance.

[throwaway64]

maximum lifetime is obtained when you store them at around 66% charge at 4C, which is the temperature of your fridge, take them out ever few months and charge them, you can get less than 1% capacity degradation a year.