The Eneloop Pro Charger w/4 AA Rechargeable Ni-MH Batteries (2550mAh) Panasonic is the perfect choice to power up the batteries. Utilizing Panasonic's advanced rechargeable battery technology, the AA batteries get charged to provide 2550mAh of power. Additionally, this charger ensures more than 500 times of charging. The rechargeable Ni-MH Batteries retain almost 85% of their charge for up to one year. Moreover, the batteries are pre-charged, which makes it convenient to directly use them. With added storage life and its adaptability to perform in extreme temperatures of down to -4 degrees Fahrenheit makes it an ideal choice for your powering solution.