Secondary battery state detection device and secondary battery state detection method

Patent metadata

Field	Value
Publication number	US-2017016962-A1
Application number	US-201615281089-A
Country	US
Kind code	A1
Filing date	Sep 30, 2016
Priority date	Apr 1, 2014
Publication date	Jan 19, 2017
Grant date	—

Abstract

A secondary battery state detecting device ( 1 ) that detects a state of a secondary battery ( 14 ) installed in a vehicle, the device including: a learning means (control unit ( 10 )) that learns element values of an equivalent circuit of the secondary battery ( 14 ) on the basis of a voltage and a current of the secondary battery ( 14 ); and a determination means (control unit ( 10 )) that compares the element values obtained through learning at different timings by the learning means and, when at least one of the element values has changed more than or equal to a predetermined threshold value, determines that the secondary battery ( 14 ) has been replaced.

First claim

1 . A secondary battery state detecting device that detects a state of a secondary battery installed in a vehicle, the device comprising:
a learning means that learns element values of an equivalent circuit of a secondary battery on the basis of a voltage and a current of the secondary battery; and a determination means that compares the element values obtained through learning at different timings by the learning means and, when at least one of the element values has changed more than or equal to a predetermined threshold value, determines that the secondary battery has been replaced.

2 . The secondary battery state detecting device according to claim 1 , wherein:
when an electric double layer capacity forming the equivalent circuit changes more than or equal to a predetermined threshold value and a change in reaction resistance is less than or equal to a predetermined threshold value, the determination means determines that the secondary battery has been replaced with a same type of secondary battery having a different degree of degradation.

3 . The secondary battery state detecting device according to claim 1 , wherein:
when the reaction resistance forming the equivalent circuit changes more than or equal to a predetermined threshold value, the determination means determines that the secondary battery has been replaced with a different type of secondary battery.

4 . The secondary battery state detecting device according to claim 1 , further comprising:
a deletion means that deletes element values of the equivalent circuit learned in the past and stored in a memory device, when the determination means determines that the secondary battery has been replaced.

5 . The secondary battery state detecting device according to claim 4 , wherein:
when the determination means determines that the secondary battery has been replaced, the deletion means deletes information showing usage history of the secondary battery that is stored in the memory device.

6 . The secondary battery state detecting device according to claim 1 , wherein:
the element values of the equivalent circuit are corrected so as to be element values at a reference temperature and a reference SOC.

7 . A secondary battery state detecting method for detecting a state of a secondary battery installed in a vehicle, the method comprising:
a learning step of learning element values of an equivalent circuit of a secondary battery on the basis of a voltage and a current of the secondary battery; and a determining step of comparing the element values obtained through learning at different timings in the learning step and, when at least one of the element values has changed more than or equal to a predetermined threshold value, determining that the secondary battery has been replaced.

Assignees

• Furukawa Electric Co Ltd
• Furukawa Automotive Systems Inc

Inventors

• Iwane Noriyasu
• Takashima Naoya
• Mitsuyama Taiji

Classifications

• H02J7/84

  Control of state of health [SOH] · CPC title

• H02J7/82

  Control of state of charge [SOC] · CPC title

• H02J7/80

  including monitoring or indicating arrangements · CPC title

• H01M10/486

  for measuring temperature · CPC title

• H01M10/48

  Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte (constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569) · CPC title