If you want to add the efficiency rate of the charger, then you cannot answer. The conversion efficiency rate of each type of charger is different. If you calculate the charging efficiency of a certain battery, you generally ignore the charger and only calculate the charge. Charge the battery power during the process. And the charging efficiency of the battery is related to the charging method of the charger, and it mainly includes: constant current type, constant voltage type and pulse. I don’t know the charging efficiency of Ni-MH, I only know that the lithium battery is charged by pulse mode to over 90%