20120313567 | POWER-SUPPLY SYSTEM, POWER-SUPPLY DEVICE AND POWER-SUPPLY METHOD - A plurality of power-supply devices, in which power generated by solar energy is stored, are allowed to exchange power among themselves. Power generated by a solar panel connected to a first power-supply device is stored in a power storage section of the first power-supply device. Power supplied by the second power-supply device, which has a power storage section for storing power generated by the solar panel, is stored in the power storage section of first power-supply device. Power stored in the power storage section of the first power-supply device is supplied externally. | 12-13-2012 |