Originally posted by Bill Bergman
Why are the very few cell phone battery fires? Oh, don't they have some internal protection circuit?
Yes, the protective circuits in cellphone battery packs prevent the fires. Most of the cell phone fires that know of recently have been traced to putting a aftermarket battery pack in. There was one case I know about of a fire after the cellphone was dropped and the phone and the battery pack were dammaged.
It is easier to design a charger that works well when the charger only has to charge one type of pack. Since our packs have a large variety of cell sizes and configurations designing a proper charger is much more difficult.