SECONDARY BATTERY DETERIORATION DETERMINATION METHOD AND SECONDARY BATTERY DETERIORATION DETERMINATION DEVICE

摘要

Provided are a secondary battery deterioration determination method and a secondary battery deterioration determination device that make it possible to detect deterioration of a secondary battery in advance even before an engine is started. When it is determined that a vehicle is in a stopped state at a step (S1), a steady-state open circuit voltage (OCV) is obtained at a step (S2) and an internal resistance (R1) is calculated at steps (S3) and (S4). When it is determined at the step (S1) that a starter (21) has started, a maximum discharge current value (Inew) is acquired at a step (S5) and a maximum discharge current value (Is) is updated at steps (S6) and (S7). The internal resistance (R1) is corrected at a step (S13) to an internal resistance (R1c) that occurs at a reference temperature, and a minimum voltage (Vs) is calculated at a step (S14). Deterioration determination of a secondary battery (10) is performed at a step (S15) by comparing the steady-state open circuit voltage (OCV) and the minimum voltage (Vs) with a predetermined threshold value.