# US 12,763,387 B2 · 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 12,763,387 B2 - Document ID: US12763387B2 - Status: Granted - Kind: B2 - Application number: 18/090,054 - Filed: 2022-12-28 - Published: 2023-07-13 - Granted: 2026-10-13 - Earliest claimed: 2022-01-11 - Assignees: Honda Motor Co., Ltd. - Applicants: Honda Motor Co., Ltd. - Inventors: Hiroto Okabe - Web page: https://patentgrep.com/patent/US12763387B2 ## CPC - 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) - G01R 31/3648: {comprising digital calculation means, e.g. for performing an algorithm} - G01R 31/389: Measuring internal impedance, internal conductance or related variables - H01M 10/425: {Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing (printed circuits H05K1/00)} - 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: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract A power storage system includes: a battery; a voltmeter; an ammeter; and processing circuitry. The processing circuitry functionally includes: a first calculation unit configured to calculate estimated internal resistance, which is an estimated value of present internal resistance, based on the voltage and the current; a second calculation unit configured to calculate charging power upper limit, based on the estimated internal resistance calculated by the first calculation unit, the present voltage, and the present current; a charge control unit configured to control charge of the battery to prevent charging power exceeding the charging power upper limit from being supplied to the battery; and a limitation unit configured to determine, based on the current, whether power fluctuation in which output power of the battery fluctuates greatly within a short period of time has occurred or not and to prohibit the second calculation unit from operating during the power fluctuation. ## Claims ### Claim 1 A power storage system comprising: a battery; a voltmeter configured to measure voltage of the battery; an ammeter configured to measure current of the battery; and processing circuitry, wherein the processing circuitry functionally includes: a first calculation unit configured to calculate estimated internal resistance, which is an estimated value of present internal resistance of the battery, based on the voltage and the current; a second calculation unit configured to calculate charging power upper limit, which is an upper limit on charging power for the battery, based on the estimated internal resistance calculated by the first calculation unit, the present voltage, and the present current; a charge control unit configured to control charge of the battery to prevent charging power exceeding the charging power upper limit from being supplied to the battery; and a limitation unit configured to determine, based on the current, whether power fluctuation in which output power of the battery fluctuates greatly within a short period of time has occurred or not and to prohibit the second calculation unit from operating during the power fluctuation. ### Claim 2 (depends on 1) The power storage system according to claim 1, wherein the limitation unit is configured to determine that the power fluctuation has occurred when a fluctuation in the current over a past predetermined period exceeds a first threshold. ### Claim 3 (depends on 1) The power storage system according to claim 1, wherein the limitation unit is configured to calculate instantaneous resistance, which is estimated internal resistance of the battery in a past predetermined period, based on a fluctuation in the current over the period and a fluctuation in the voltage over the period, and the limitation unit is configured to determine that the power fluctuation has occurred when a ratio of the instantaneous resistance to the estimated internal resistance is below a second threshold. ### Claim 4 (depends on 1) The power storage system according to claim 1, wherein the charge control unit is configured to control charge of the battery based on: when operation of the second calculation unit is not prohibited by the limitation unit, the charging power upper limit calculated by the second calculation unit based on the estimated internal resistance, the present voltage, and the present current; and when the operation of the second calculation unit is prohibited by the limitation unit, the charging power upper limit calculated immediately before the operation of the second calculation unit is prohibited. ### Claim 5 (depends on 2) The power storage system according to claim 2, wherein the charge control unit is configured to control charge of the battery based on: when operation of the second calculation unit is not prohibited by the limitation unit, the charging power upper limit calculated by the second calculation unit based on the estimated internal resistance, the present voltage, and the present current; and when the operation of the second calculation unit is prohibited by the limitation unit, the charging power upper limit calculated immediately before the operation of the second calculation unit is prohibited. ### Claim 6 (depends on 3) The power storage system according to claim 3, wherein the charge control unit is configured to control charge of the battery based on: when operation of the second calculation unit is not prohibited by the limitation unit, the charging power upper limit calculated by the second calculation unit based on the estimated internal resistance, the present voltage, and the present current; and when the operation of the second calculation unit is prohibited by the limitation unit, the charging power upper limit calculated immediately before the operation of the second calculation unit is prohibited. ### Claim 7 A power storage system comprising: a battery; a voltmeter configured to measure voltage of the battery; an ammeter configured to measure current of the battery; and processing circuitry, wherein the processing circuitry functionally includes: a first calculation unit configured to calculate estimated internal resistance, which is an estimated value of present internal resistance of the battery, based on the voltage and the current; a second calculation unit configured to calculate discharging power upper limit, which is an upper limit on discharging power for the battery, based on the estimated internal resistance calculated by the first calculation unit, the present voltage, and the present current; a discharge control unit configured to control discharge of the battery to prevent discharging power exceeding the discharging power upper limit from being discharged from the battery; and a limitation unit configured to determine, based on the current, whether power fluctuation in which output power of the battery fluctuates greatly within a short period of time has occurred or not and to prohibit the second calculation unit from operating during the power fluctuation.