SOLAR CELL SYSTEM

摘要

Disclosed is a solar cell system which can supply an output from a solar cell to a secondary battery without involving any DC/DC converter and can therefore charge the secondary battery with high efficiency, and can also supply an electric power from the secondary battery to a load without involving any DC/DC converter and can therefore operate the load stably. The solar cell system comprises a secondary battery (1), a solar cell (2) which can charge the secondary battery (1), a load (3) to which an electric power is supplied from the solar cell (2) and the secondary battery (1), and a power supply circuit (4) through which an electric power is supplied from the commercial power supply (9) to the load (3), wherein an output voltage of the solar cell (2) is supplied to the secondary battery (1) without the need of stabilizing the output voltage. The solar cell system also comprises a control circuit (6) which can detect the residual capacity of the secondary battery (1) and a solar cell charge switch (12) which can control the supply of an electric power from the solar cell (2) to the secondary battery (1), wherein control circuit (6) can turn on or off the solar cell charge switch (12) in accordance with the residual capacity of the secondary battery (1), and an electric power is supplied from the secondary battery (1) to the load (3) while charging or discharging the secondary battery (1) and while connecting the secondary battery (1) to the load (3).