Abstract: The present invention relates to a type of portable emergency power supply for use when storage batteries of mobile appliances such as cellular telephones, radios, camcorders, laptops and mini cassette players are discharged or become unusable. In particular, by utilizing solar cells, the present invention can supply power to mobile phones, laptops and mini cassette players and other devices during the daytime when the sun shines. The present invention provides a portable multi-voltage power source device that is capable of generating various levels of power voltages for diverse appliances requiring different electric voltages. The present invention includes at least one solar cell plate formed of a plurality of solar cells connected to each other and a power source selection unit to select one of a plurality of voltages by coupling the positive and negative poles of the connected solar cells in selected fashions.