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 S1405 Rechargeable Lithium-ion 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 S1405 Rechargeable Lithium-ion Battery Pack guarantees you never run out of power.