Patent ID: 6265877
Filing Date: 2001-07-24
Classification: H01M,Y02E

Abstract:
A method of determining an end of discharge voltage of a secondary battery which has a positive electrode of nickel-hydroxide based on a state of charge (SOC) of the battery, comprising the steps of:setting an allowable lower limit of the SOC of the battery;determining a voltage at which the SOC is the set lower limit after a first discharge of the battery;determining voltages at which the SOC is the set lower limit after subsequent discharges of the battery after recharge of the battery, wherein the voltage at which the SOC is the set lower limit for discharges after the first discharge gradually decreases in view of a memory effect of the battery; anddetermining the end of discharge voltage in consideration of the voltages at which the SOC is the set lower limit after the first and subsequent discharges whereby the end of discharge voltage is lower than the voltage at which the SOC is the set lower limit after the first discharge.