This device has 4 power systems: solar power; alkaline battery; dynamo manual winding power; AC/DC adaptor power. For solar power, harness the sun's free energy at no cost. The radio works instantly under sunlight, plus the built-in fully automatic rechargeable system will store energy during the day for night-time use. For dynamo power, crank the handle briefly to generate power for radio or blinking light. Use battery power to increase usage time. Use 4.5V AC/DC adaptor to charge the battery. (AC/DC adaptor not included.) (C/77)