cooperredWell, this one is apparently more powerful but still has the same limitation as the original - once the battery is dead, you gonna have to replace it.
AnzialFor the soldering iron wielders I can't imagine reviving it being much harder than replacing the battery in an electric toothbrush. Maybe even mod it with high discharge li-ions.
SennyThe old version did not have a user-replaceable battery. Pretty sure this one doesn't either. To install a new one, you'll need to destroy the casing and the thing will simply fall apart.