... Specification1, Solar Panel(mono or multi-crystalline): 5.5V/110mA2, Li-ion rechargeable Battery: 3.7V/2,000mAh3, Mini USB input: ... 18-22 hrs (via solar panel, under full sunlight condition)6, On/off button: press to start charging7, Power display: 4 LED indicators ... shows power level, each represents 25% of battery ...