This helps to extend the overall battery life and accelerate the charging process. It has 3 active charging colours to help identify when the battery is charged, and to what level. When it is used in conjunction with the charging adaptor ADP0, this charger offers also the possibility of charging Ni-MH slide batteries from 9.6v-24v. Or when used with charging adaptor ADP04, this charger offers the possibility to charge Ni-Cad and Ni-MH rod and block batteries from 7.2v-18v.