Electrical storage capacitor system having initializing function

There is disclosed an electrical storage capacitor system (3) that efficiently initializes itself to its initial state during pause intervals between charging/discharging cycles of operation without providing any special initializing cycles. The capacitor system (3) comprises capacitors connected in series to store electricity, a variation decision means for judging the amount of variation in amount of charge between the capacitors, an operation decision means for judging whether the capacitors are being charged or discharged, and a initializing charging means for charging the capacitors to initialize themselves to their initial state according to the results of decisions made by the variation decision means and by the operation decision means. The variation decision means judges the amount of variation in the amount of charge among the capacitors according to the output voltage from the capacitors connected in series when any one of the capacitors is fully charged. The operation decision means makes a decision as to whether the capacitors are being charged or discharged with large current and a decision as to whether the charge level is within a given tolerable level. The initializing charging means comprises parallel monitors for causing the charging current to bypass the capacitors at a first set voltage and voltage detection means for detecting a second set voltage used to judge that the initializing charging has ended. The second set voltage is higher than the first set voltage.