SECONDARY BATTERY SYSTEM

摘要

Disclosed is a secondary battery system which, when charging a battery pack in a charger, makes it possible to precisely equalize the voltages of the individual cells without needing to greatly increase the capability of the voltage equalizer device. The disclosed secondary battery system is at least provided with a battery pack (1) configured by connecting multiple single secondary cells (1a), a voltage equalizer (BL) which equalizes the variation of the voltages between the single cells (1a), a charger (3) and a charger controller (CC). The charger controller (CC) is configured such that when the cell voltage of any of the multiple single cells (1a) reaches a set voltage for suppressing voltage rise, the current flowing in the entire battery pack (1) is controlled to become zero or an amount of current at which the variation in voltages between the single cells can be reduced by the aforementioned voltage equalizer. The voltage equalizer (BL) is configured so as to equalize the voltage variation between the single cells in parallel to the control exercised by the charger control device (CC).