METHOD OF ESTIMATING BATTERY CONDITION, AND METHOD OF DETERMINING ENGINE START

摘要

PROBLEM TO BE SOLVED: To provide a precise battery condition estimating method suitable for a vehicle system for executing idling stop/start, and an engine start determining method allowing determination in real time. SOLUTION: A voltage VC per one cell in 0.2 sec of lapse time after 250A discharge at 25°C, and a residual capacity Q are measured in each of different SOH(state of health). SOH means the ratio of the present fully charged capacity to the initial fully chareged capacity. Measured results are plotted via the SOHs, and are approximated to one broken-line graph to obtain a correspondence correlation data between the residual capacity Q and the discharge voltage VC per one cell. One of the the residual capacity Q and the discharge voltage VC is estimated from the other thereof based on the correlation data. The battery condition in the residual capacity Q or the discharge voltage VC is estimated precisely without inspecting the SOH. COPYRIGHT: (C)2004,JPO