This solar powered battery charger is great for emergencies and is also popular among outdoor enthusiasts. Solar powered battery charger for 2: D, C, AA or AAA size rechargeable batteries. A built-in blocking diode prevents the discharging of batteries when sunlight is not available. It has an adjustable stand to allow the best positioning towards the sun. Complete instructions with charging times included. Note: you can charge two batteries of the same size and kind at a one time