Battery type suitable for 1 to 8pcs aaaaa ni mh batteries rugged able to withstand drops of up to 1 metre reverse polarity protection the electrical circuit protects the charger and batteries from being damaged by incorrectly installed batteries over current protection maintain a constant charging current during the charging cycle low battery leakage current if the battery charger is not connected to input power and left in the charger the charger will discharge the batteries using a p