The Solar/Hand-Crank Powered Emergency Flashlight, Radio, & Cell Phone Charger unit uses a rechargeable Ni-Cad battery: a rechargeable battery that has the ability of recharging over 500 times. This remarkable radio and light recharges these batteries using either the hand crank and/or solar panel to charge them. You can simply charge the battery in the sun, charge it in artificial light, or charge it using the hand crank. After the battery has been fully charged and discharged, one minute of hand cranking produces 10 minutes of play.