BATTERY STATE MEASURING METHOD AND APPARATUS

• US 20130093430A1
• Filed: 10/04/2012
• Published: 04/18/2013
• Est. Priority Date: 10/12/2011
• Status: Abandoned Application

• Current Assignee: Mitsumi Electric Co., Ltd. (MinebeaMitsumi Inc.)
• Original Assignee: Mitsumi Electric Co., Ltd. (MinebeaMitsumi Inc.)
• Inventors: HAGIMORI, Hitoshi, Mikami, Yosuke
• Application Number:
  US13/644,673
• Publication Number:
  US 20130093430A1
• Time in Patent Office: Days
• US Class Current: 324/434
• CPC Class Codes: G01R 31/367 Software therefor, e.g. for battery testing using modelling or look-up tables
• CPC Class Codes: G01R 31/3835 involving only voltage measurements
• CPC Class Codes: G01R 31/392 Determining battery ageing or deterioration, e.g. state of health
• CPC Class Codes: H01M 10/482 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 2010/4271 Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

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.

Claims

1. A battery state measuring method, comprising:

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.

2. The battery state measuring method as claimed in claim 1, wherein the prediction step includes:

a voltage difference calculating step of utilizing a relationship between the one or more parameters indicative of one or more battery states and a voltage difference between the transient open-circuit voltage and the stabilized open-circuit voltage to calculate the voltage difference that corresponds to the one or more parameters detected by the parameter detecting step; and

a voltage calculating step of calculating the stabilized open-circuit voltage by use of the transient open-circuit voltage detected by the voltage detecting step and the voltage difference calculated by the voltage difference calculating step.

3. The battery state measuring method as claimed in claim 1, wherein the one or more parameters indicative of one or more battery states include at least one of a state-of-charge, temperature, and a degradation rate of the secondary battery.

4. An battery state measuring apparatus, comprising:

a voltage detecting unit configured to detect 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 configured to detect 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 unit configured to utilize 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 unit and the one or more parameters detected by the parameter detecting unit.

5. A battery protection apparatus, comprising:

the battery state measuring apparatus of claim 4; and

a protection circuit configured to protect the secondary battery.

6. A battery pack, comprising:

the battery state measuring apparatus of claim 4; and

the secondary battery.

7. An electronic apparatus operating on a secondary battery, comprising:

the battery state measuring apparatus of claim 4.