This PowerOne p10 Pen Charger charges one p10 ACCUplus Ni-HM cell battery using 2 AAA (LR03) Alkaline batteries (included). This allows you to charge your p10 battery without a wall socket in approx. 5 hours. When the battery is charging a green light will blink. Once fully charged, the light on the PowerOne p10 charger will turn red. The p10 ACCUplus rechargeable batteries must be ordered separately.