| 摘要 |
<p>PROBLEM TO BE SOLVED: To relax the partial discharging state of a secondary battery even when the output power of a solar battery varies. SOLUTION: A secondary battery 4 is allowed to be discharged only in two case of (1) that a terminal voltage of the secondary battery 4 is higher than a discharging stop voltage that is specified by a power source 9, and a terminal voltage of an electric double-layer capacitor 3 is less than a duty-threshold voltage that is specified by a power source 14, and (2) that a terminal voltage of the secondary battery 4 is higher than the discharging stop voltage that is specified by the power source 9 and is within a time range that is specified by a discharging stop command signal. Thereby, the secondary battery 4 is prevented from getting into a partial discharging state better than in the conventional device even when output power of the solar battery 1 varies accompanying a rapid change of sunlight intensity, and deterioration in the secondary battery 4 caused by the partial discharging state can be suppressed.</p> |
