Battery charger is built-into the battery case with LED charge status indicator and automatic charge protection (stops charging when batteries are full). Using the battery pack saves you money: While rechargeable batteries cost more initially, they can be reused hundreds of times and last for years. Rechargeable battery use greatly reduces the quantity of batteries manufactured, used and discarded. The rechargeable battery pack guarantees you never run out of power. Battery Type: Lithium-Ion; Battery Size: 3.7V; For Use With: S602R, S602MR; Battery Capacity: 2200 mAh.