| 摘要 |
PROBLEM TO BE SOLVED: To increase efficiency in charging, shorten power receiving time, and prevent reduction in capacity of a secondary battery by a method wherein before starting to charge the secondary battery, a power storage apparatus is operated at large load and thereafter, the secondary battery is charged with the apparatus being operated at small load. SOLUTION: The inside temperature of a power storage apparatus (for example, a freezer having a secondary battery) is detected by an inside thermometer 5 to be supplied as a control signal to an inverter 4. The inverter 4 outputs a PWM signal having a duty ratio corresponding to the inside temperature and supplied it to a compressor to drive it into a freezing operation. A secondary battery 11 and a capacitor 3 are connected through a relay 9 for discharging controlled by a control circuit 6 and a DC-DC converter 10. For a specified period of time (for example, one hour) before starting night time charging, the set temperature is reduced to operate the compressor 8 at full speed and sufficiently reduce the inside temperature. Thereafter, the compressor 8 is operated at low speed and the secondary battery 11 is charged with a large current flow using excessive power and then the secondary battery is further charged with a small current flow. |
