19.2 volt charging types

The lithium batteries require a special charger. Some of them have a third wire for sensing and some also sense for temp. A charger for ni-cad and ni-mh batteries sense the voltage peak and cut off the charge to a trickle charge, at least the chargers for my model aircraft do that. There is also a difference in the charge rate for all three batteries. Some ni-cad/ni-mh don't have a cutoff feature and keep charging at full rate and they need to be monitored all the time. The best way with those chargers is to have a battery fully discharged and then charge it for the length of time that the voltage and capacity of the battery requires and unplug it at the end of that time frame other wise the batteries will over heat and be damaged.

Unless the charger is designed to be able to charge each type battery it should not be used.