How old was the equipment?
Due to a thread last year in an electronics.repair group I keep my 19.2 volt Craftsman chargers on a timer to keep from overheating. SFSG. Several years old now. Seems to be a common problem. Having 7 tools, would have no choice but to replace or make my own.
Saw Chicago Pneumatic in the recall(was expecting lithium). For some reason associate that with Harbor Freight.