| 摘要 |
Provided is a battery state of charge estimation device and a battery state of charge estimation method with which the accuracy of estimating a state of charge is further improved. The battery state of charge estimation device (1) detects the energization state (S) of a rechargeable battery (B) immediately before the supply of a charge/discharge current is stopped. The voltage value (Va) between both electrodes of the rechargeable battery (B) after the supply of the charge/discharge current has been stopped is measured. The elapsed time (Ta), from when the supply of the charge/discharge current was stopped to when the voltage value (Va) between both electrodes of the rechargeable battery (B) was measured, is measured. For each detected energization state (S), measured voltage value (Va), measured elapsed time (Ta), and a plurality of energization states (S) immediately before the supply of the charge/discharge current is stopped, an open-circuit voltage (OCV) is estimated using open-circuit voltage relationship information (J) pertaining to the relationship between changes in the voltage value between both electrodes of the rechargeable battery (B) and the open-circuit voltage (OCV) of the rechargeable battery (B) after the current supply has been stopped, said open-circuit voltage relationship information being pre-stored in the ROM of a control unit (30). In addition, the state of charge (SOC) of the battery is estimated on the basis of the estimated open-circuit voltage (OCV). |
