This charger will charge four batteries of the same size simultaneously. On a good sunny day, 4 x AA 2000mAh NiMh batteries can be charged in as little as 6 hours. The batteries are charged within the case, which features a fold out stand for directing the solar panel towards the sun. The solar charger measures 165mm (W) x 130mm (H) x 55mm (D), and the carry handle extrudes a further 43mm to the height of the unit. The charger is supplied complete with a 5-way spider for powering small electrical goods such as personal stereos, toys or torches. The built-in blocking diode prevents reverse charging. Please note that the charging circuit is designed to charge 4 rechargeable batteries in an in-series circuit system (4.8V).