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 performing 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 an open circuit voltage Ec per one cell are measured in each of different SOHs. Measured results are plotted via the SOHs, and are approximated to one broken-line graph to obtain a correspondence correlation data between the open circuit voltage Ec per one cell and the discharge voltage VC per one cell. One of the discharge voltage VC and the open circuit voltage Ec is estimated from the other thereof based on the correlation data. The battery condition in the circuit voltage Ec or the discharge voltage VC is estimated precisely without inspecting the SOH. COPYRIGHT: (C)2004,JPO