# US 2013/0154574 A1 · Charge Acceptance Limit Determination Apparatus and Charge Acceptance Limit Determination Method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0154574 A1 - Document ID: US20130154574A1 - Status: Published application - Kind: A1 - Application number: 13/769,659 - Filed: 2013-02-18 - Published: 2013-06-20 - Earliest claimed: 2010-09-24 - Assignees: Furukawa Automotive Systems Inc.; Furukawa Electric Co., Ltd. - Inventors: Shinichi NOMOTO - Web page: https://patentgrep.com/patent/US20130154574A1 ## CPC - H02J 7/80: including monitoring or indicating arrangements - G01R 31/3842: combining voltage and current measurements - 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 7/82: Control of state of charge [SOC] - G01R 31/367: Software therefor, e.g. for battery testing using modelling or look-up tables - G01R 31/389: Measuring internal impedance, internal conductance or related variables - G01R 31/392: Determining battery ageing or deterioration, e.g. state of health - Y02E 60/10: Energy storage using batteries - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - 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 - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract A charge acceptance limit determination apparatus includes a voltage measuring unit that measures a voltage of a secondary battery, a current measuring unit that measures an electric current flowing through the secondary battery, and a determining unit that determines whether or not the secondary battery has reached a charge acceptance limit in accordance with a position on a current-voltage plane of a voltage value and a current value that are measured by the voltage measuring unit and the current measuring unit. ## Claims ### Claim 1 A charge acceptance limit determination apparatus comprising: a voltage measuring unit that measures a voltage of a secondary battery; a current measuring unit that measures an electric current flowing through the secondary battery; and a determining unit that determines whether or not the secondary battery has reached a charge acceptance limit in accordance with a position on a current-voltage plane of a voltage value and a current value that are measured by the voltage measuring unit and the current measuring unit. ### Claim 2 (depends on 1) The charge acceptance limit determination apparatus according to claim 1, wherein the determining unit determines whether or not the secondary battery has reached a charge acceptance limit based on a distance of a position corresponding to the voltage value and the current value from a predetermined base point on the current-voltage plane. ### Claim 3 (depends on 1) The charge acceptance limit determination apparatus according to claim 1, wherein the determining unit obtains, on the current-voltage plane, a midpoint between a position corresponding to the voltage value and the current value that are newly measured and a position corresponding to the voltage value and the current value that have been previously measured, and determines whether or not the secondary battery has reached a charge acceptance limit based on a distance of the midpoint from a predetermined base point. ### Claim 4 (depends on 3) The charge acceptance limit determination apparatus according to claim 3, wherein the determining unit determines whether or not the secondary battery has reached a charge acceptance limit based on a distance of the predetermined base point from a midpoint between the previously obtained midpoint and the newly obtained midpoint. ### Claim 5 (depends on 2) The charge acceptance limit determination apparatus according to claim 2, wherein, when the distance is smaller than a predetermined threshold, the determining unit determines that the secondary battery has reached a charge acceptance limit. ### Claim 6 (depends on 2) The charge acceptance limit determination apparatus according to claim 2, wherein, when a weighted average of the distances is smaller than a predetermined threshold, the determining unit determines that the secondary battery has reached a charge acceptance limit. ### Claim 7 (depends on 2) The charge acceptance limit determination apparatus according to claim 2, wherein the base point is reset depending on degradation of the secondary battery. ### Claim 8 (depends on 1) The charge acceptance limit determination apparatus according to claim 1, wherein the determining unit has a reference value of a voltage value and a reference value of a current value and, when at least one of a measured voltage value and a measured current value is less than or equal to these reference values, the relevant measured value is excluded from a target of the determination. ### Claim 9 (depends on 1) The charge acceptance limit determination apparatus according to claim 1, wherein the determining unit has a proper range for a voltage value and a proper range for a current value, and when one of a measured voltage value and a measured current value is out of the proper ranges, the relevant measured value is corrected to a predetermined specified value. ### Claim 10 (depends on 1) The charge acceptance limit determination apparatus according to claim 1, comprising: a calculating unit that calculates an SOC indicating a state of charge of the secondary battery, wherein an SOC calculated by the calculation unit when the determining means has determined that the charge acceptance limit has reached is taken as a charge acceptance limit SOC. ### Claim 11 (depends on 10) The charge acceptance limit determination apparatus according to claim 10, wherein, after the charge acceptance limit SOC has been set, when an SOC having a value greater than the charge acceptance limit SOC has been calculated by the calculating unit, the charge acceptance limit SOC is updated with the relevant SOC. ### Claim 12 A charge acceptance limit determination method comprising: measuring a voltage of a secondary battery to obtain a voltage value; measuring an electric current flowing through the secondary battery to obtain a current value; determining whether or not the secondary battery has reached a charge acceptance limit in accordance with a position on a current-voltage plane of the voltage value and the current value. ### Claim 13 (depends on 12) The method according to claim 12 wherein said determining whether or not the secondary battery has reached a charge acceptance limit in accordance with a position on a current-voltage plane of the voltage value and the current value is performed by a processor in cooperation with a memory.