PSA: check drawer with old devices regularly. Found a swollen battery in my PSP, after not touching it 7-8 years. Same with an old motorola A920 (quite old). Who knows how many years both had swollen batteries but, then again, newer batteries have much more power to contain.
If you think about it though, there are billions of shoddily made lithium batteries sitting in drawers everywhere for years now, and yet there are only about 10 fire incidents a day.
So like many other boogeymen, driving to work is still far more dangerous. Back of the napkin shows about 100x more likely to die in a car crash than experience a battery incident in any given year.
