# US 2019/0170831 A1 · Battery diagnosis method, battery diagnosis program, battery management apparatus, and power storage system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0170831 A1 - Document ID: US20190170831A1 - Status: Published application - Kind: A1 - Application number: 16/273,180 - Filed: 2019-02-12 - Published: 2019-06-06 - Earliest claimed: 2016-09-16 - Assignees: Panasonic Intellectual Property Management Co., Ltd. - Applicants: Panasonic Intellectual Property Management Co., Ltd. - Inventors: Tomokazu SADA - Web page: https://patentgrep.com/patent/US20190170831A1 ## CPC - G01R 31/389: Measuring internal impedance, internal conductance or related variables - G01R 19/16542: {for batteries (charge condition monitoring in G01R31/36)} - G01R 31/3842: combining voltage and current measurements - G01R 31/392: Determining battery ageing or deterioration, e.g. state of health - H01M 10/42: Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells (H01M10/60 takes precedence) - H01M 10/425: {Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing (printed circuits H05K1/00)} - H01M 10/44: Methods for charging or discharging (circuits for charging H02J7/00) - H01M 10/441: {for several batteries or cells simultaneously or sequentially} - H01M 10/48: 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) - H02J 7/00: Circuit arrangements for charging or discharging batteries or for supplying loads from batteries - H02J 7/54: Passive balancing, e.g. using resistors or parallel MOSFETs - G01R 31/386: {using test-loads} - G01R 31/396: Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery - H01M 2010/4271: {Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing} - H01M 2010/4278: {Systems for data transfer from batteries, e.g. transfer of battery parameters to a controller, data transferred between battery controller and main controller} - H01M 2220/20: Batteries in motive systems, e.g. vehicle, ship, plane - Y02E 60/10: Energy storage using batteries - Y02T 10/70: Energy storage systems for electromobility, e.g. batteries - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A control unit in a battery management apparatus discharges constant direct current from a battery for a predetermined time period or charges the battery with the constant direct current for the predetermined time period to diagnose a state of the battery. A change point is identified where a rise in voltage given by subtracting open circuit voltage of the battery from measured voltage of the battery is varied from a curved line shape to a straight line shape with respect to transition of an increase of a value in which an elapsed time since start of charge-discharge is defined as a square root of time. A rise in voltage from the voltage when the charge-discharge is started to the change point is identified as a rise in voltage caused by resistance components of electrolyte, a negative electrode, and a positive electrode of the battery and a rise in voltage after the change point is identified as a rise in voltage caused by a diffusion resistance component of the battery. ## Claims ### Claim 1 A battery diagnosis method comprising: discharging constant direct current from a battery for a predetermined time period or charging the battery with the constant direct current for the predetermined time period; measuring voltage of the battery; identifying a change point where a rise in voltage given by subtracting open circuit voltage of the battery from the measured voltage of the battery is varied from a curved line shape to a straight line shape with respect to transition of an increase of a value in which an elapsed time since start of charge-discharge is defined as a square root of time; identifying a rise in voltage from the voltage when the charge-discharge is started to the change point as a rise in voltage caused by resistance components of electrolyte, a negative electrode, and a positive electrode of the battery and identifying a rise in voltage after the change point as a rise in voltage caused by a diffusion resistance component of the battery; and identifying a rise in voltage until a predetermined time set in advance based on frequency response of the resistance component of the negative electrode of the battery elapses since the start of the charge-discharge as a rise in voltage caused by the electrolyte and the negative electrode of the battery. ### Claim 2 A battery diagnosis program causes a computer to perform a process comprising: identifying a change point where a rise in voltage given by subtracting open circuit voltage of the battery from measured voltage of the battery is varied from a curved line shape to a straight line shape with respect to transition of an increase of a value in which an elapsed time since start of control, in which constant direct current is discharged from a battery for a predetermined time period or the battery is charged with the constant direct current for the predetermined time period, is defined as a square root of time; identifying a rise in voltage from the voltage when charge-discharge is started to the change point as a rise in voltage caused by resistance components of electrolyte, a negative electrode, and a positive electrode of the battery and identifying a rise in voltage after the change point as a rise in voltage caused by a diffusion resistance component of the battery; and identifying a rise in voltage until a predetermined time set in advance based on frequency response of the resistance component of the negative electrode of the battery elapses since the start of the charge-discharge as a rise in voltage caused by the electrolyte and the negative electrode of the battery. ### Claim 3 A battery management apparatus includes a current measurement unit that measures current flowing through a battery; a voltage measurement unit that measures voltage of the battery; and a control unit that discharges constant direct current from the battery for a predetermined time period or charges the battery with the constant direct current for the predetermined time period to diagnose a state of the battery, wherein the control unit identifies a change point where a rise in voltage given by subtracting open circuit voltage of the battery from the measured voltage of the battery is varied from a curved line shape to a straight line shape with respect to transition of an increase of a value in which an elapsed time since start of charge-discharge is defined as a square root of time, wherein the control unit identifies a rise in voltage from the voltage when the charge-discharge is started to the change point as a rise in voltage caused by resistance components of electrolyte, a negative electrode, and a positive electrode of the battery and identifies a rise in voltage after the change point as a rise in voltage caused by a diffusion resistance component of the battery, and wherein the control unit identifies a rise in voltage until a predetermined time set in advance based on frequency response of the resistance component of the negative electrode of the battery elapses since the start of the charge-discharge as a rise in voltage caused by the electrolyte and the negative electrode of the battery. ### Claim 4 (depends on 3) The battery management apparatus according to claim 3, wherein the control unit calculates a combined resistance value of the electrolyte, the negative electrode, and the positive electrode of the battery by dividing the rise in voltage caused by the resistance components of the electrolyte, the negative electrode, and the positive electrode of the battery by the constant direct current, wherein the control unit derives a diffusion resistance factor of the battery based on a rate of the rise in voltage caused by the diffusion resistance component of the battery, wherein the control unit calculates a combined resistance value of the electrolyte and the negative electrode of the battery by dividing the rise in voltage caused by the electrolyte and the negative electrode of the battery by the constant direct current, and wherein the control unit calculates the resistance value of the positive electrode of the battery by subtracting the combined resistance value of the electrolyte and the negative electrode of the battery from the combined resistance value of the electrolyte, the negative electrode, and the positive electrode of the battery. ### Claim 5 (depends on 4) The battery management apparatus according to claim 4, wherein the control unit performs at least one of output of an alert and stop of the charge-discharge of the battery if the calculated diffusion resistance factor is higher than or equal to a deterioration determination threshold value for the diffusion resistance, wherein the control unit performs at least one of the output of an alert and the stop of the charge-discharge of the battery if the calculated resistance value of the positive electrode is higher than or equal to a deterioration determination threshold value for the positive electrode resistance, and wherein the control unit performs at least one of the output of an alert and the stop of the charge-discharge of the battery if the calculated combined resistance value of the electrolyte and the negative electrode is higher than or equal to a deterioration determination threshold value for the combined resistance of the electrolyte and the negative electrode. ### Claim 6 (depends on 4) The battery management apparatus according to claim 4, wherein the control unit changes an upper limit of at least one of charge current and discharge current of the battery based on the calculated diffusion resistance factor, the calculated resistance value of the positive electrode, and the calculated combined resistance value of the electrolyte and the negative electrode. ### Claim 7 (depends on 4) The battery management apparatus according to claim 4, wherein the control unit estimates a remaining usage period or a remaining charge-discharge count of the battery based on transition of the calculated diffusion resistance factor, the calculated resistance value of the positive electrode, and the calculated combined resistance value of the electrolyte and the negative electrode. ### Claim 8 (depends on 3) The battery management apparatus according to claim 3, wherein the control unit performs control so as to cause the constant direct current to flow through the battery for 30 seconds or more. ### Claim 9 (depends on 3) A power storage system comprising: a battery module including a battery; and the battery management apparatus according to claim 3, which manages the battery module. ### Claim 10 (depends on 4) A power storage system comprising: a battery module including a battery; and the battery management apparatus according to claim 4, which manages the battery module. ### Claim 11 (depends on 5) A power storage system comprising: a battery module including a battery; and the battery management apparatus according to claim 5, which manages the battery module. ### Claim 12 (depends on 6) A power storage system comprising: a battery module including a battery; and the battery management apparatus according to claim 6, which manages the battery module. ### Claim 13 (depends on 7) A power storage system comprising: a battery module including a battery; and the battery management apparatus according to claim 7, which manages the battery module. ### Claim 14 (depends on 8) power storage system comprising: a battery module including a battery; and the battery management apparatus according to claim 8, which manages the battery module.