BATTERY STATE MEASURING DEVICE AND BATTERY STATE MEASURING METHOD

To provide a battery state measuring device and a battery state measuring method with which it is possible to measure the battery state of a secondary battery when a current is flowing.SOLUTION: A measuring device 10 measures the battery state of a battery 1. The measuring device 10 comprises: a voltage acquisition unit 43 for acquiring a pre-start voltage before a charge or discharge of a fixed current begins, an end time voltage when the charge or discharge of a fixed current is terminated, and a relaxation voltage when a voltage change occurring after the charge or discharge of a fixed current became a steady state; an ultimate voltage calculation unit 48 for calculating an ultimate voltage that is reached, when the charge or discharge of a fixed current is terminated from the pre-start voltage state, by an equivalent circuit having been fitted on the basis of a complex impedance acquired when being at the pre-start voltage; and a dynamic ΔV calculation unit 51 for calculating a voltage that indicates the battery state associated with the fixed current on the basis of a first voltage difference that is a difference between the pre-start voltage and the relaxation voltage and a second voltage difference that is a difference between the end time voltage and the ultimate voltage.SELECTED DRAWING: Figure 1 【課題】電流が流れているときの二次電池の電池状態を測定することのできる電池状態測定装置及び電池状態測定方法を提供する。【解決手段】測定装置１０は、電池１の電池状態を測定する。測定装置１０は、一定電流の充電又は放電が開始される前の開始前電圧と、一定電流の充電又は放電が終了されるときの終了時電圧と、一定電流の充電又は放電の終了後に生じる電圧変化が定常状態になったときの緩和電圧とを取得する電圧取得部４３と、開始前電圧であるときに取得した複素インピーダンスに基づいてフィッティングされた等価回路が、開始前電圧である状態から一定電流の充電又は放電が終了されるときに到達する到達電圧を算出する到達電圧算出部４８と、開始前電圧と緩和電圧との間の差である第１電圧差と、終了時電圧と到達電圧との間の差である第２電圧差との差に基づいて一定電流に関連する電池状態を示す電圧を算出する動的なΔＶ算出部５１とを備える。【選択図】図１