Battery state measuring method and apparatus

Abstract

A battery state measuring method includes a voltage detecting step of detecting a transient open-circuit voltage of a secondary battery at an end of a fixed-length period starting at a termination of charging or discharging of the secondary battery, a parameter detecting step of detecting one or more parameters indicative of one or more battery states of the secondary battery at or prior to the end of the fixed-length period, and a prediction step of utilizing a relationship between the transient open-circuit voltage, the one or more parameters indicative of one or more battery states, and a stabilized open-circuit voltage of the secondary battery as observed after the end of the fixed-length period to obtain the stabilized open-circuit voltage that corresponds to the transient open-circuit voltage detected by the voltage detecting step and the one or more parameters detected by the parameter detecting step.

Description

technical field [0001] The present invention relates to a technique for measuring the state of a secondary battery. Background technique [0002] As the prior art, there is known such a battery residual capacity calculation device: by detecting the open circuit voltage of the battery and comparing it with the data of the open circuit voltage of the battery - the remaining capacity of the battery, the remaining capacity of the battery is calculated (for example, refer to patent Literature 1). [0003] patent documents [0004] Patent Document 1: Japanese Patent Application Laid-Open No. 3-180783 [0005] However, the time until the open circuit voltage of the secondary battery becomes stable varies depending on conditions such as the ambient temperature, deterioration rate, and resistance value of the secondary battery. Therefore, it may be necessary to wait for a long time to detect a stable open circuit voltage. In this case, the chances of correcting the remaining capac...

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Problems solved by technology

[0005] However, the time until the open circuit voltage of the secondary battery becomes stable varies depending on conditions such as the ambient temperature, deterioration rate, and resistance value of the secondary battery, so it may be necessary to wait for a long time to detect a stable open circuit voltage.

In this case, the chance of correcting the remaining capacity (remaining capacity) of the secondary battery by using the detected value of the open circuit voltage decreases, and therefore, the calculation error of the remaining capacity may increase.

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