METHOD AND DEVICE FOR DETERMINING RESIDUAL CAPACITY OF STORAGE BATTERY MOUNTED IN VEHICLE

摘要

PROBLEM TO BE SOLVED: To provide a method and device for determining residual capacity or a state of charge (SOC) during discharge of a storage battery mounted in a vehicle, especially in an idling stop (IS) time. SOLUTION: (1) A relational expression showing a relation between an inter-terminal voltage and a current ratio value with respect to each residual capacity (Qn) of the storage battery or percentage of SOC is previously determined (S1). (2) When discharge is performed from the storage battery in the IS time (S2), (2a) an inter-terminal voltage (V) and discharge current (I) of the storage battery are measured (S3); (2b) the current ratio value (C) is calculated by dividing the measured current (I) by a previously obtained full charge capacity (Ah) of the storage battery (S4); (2c) an inter-terminal voltage (VQn) to the residual capacity or the percentage of SOC is determined by substituting the calculated current ratio value (C) into the previously obtained relational expression (S5); and (2d) the residual capacity or the percentage of SOC is determined by comparing and collating the obtained inter-terminal voltage (VQn) with the measured inter-terminal voltage (V). COPYRIGHT: (C)2005,JPO&NCIPI