The Sony Cycle Energy BCG34HLD4KN Power Charger is ideal to powerup rechargeable AA batteries. It includes four rechargeable 2000mAhAA batteries that can last up to three times longer than alkalinebatteries. Low self-discharge rate ensures a long life even whenthe batteries are stored. The batteries come pre-charged for usestraight out of the box. On the whole, this compact battery chargeroffers a reliable, quick and convenient way to charge your batteries.