# US 5,703,469 A · System for determining battery conditions > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,703,469 A - Document ID: US5703469A - Status: Granted - Kind: A - Application number: 08/655,767 - Filed: 1996-05-30 - Granted: 1997-12-30 - Earliest claimed: 1995-06-05 - Assignees: Honda Giken Kogyo Kabushiki Kaisha - Inventors: Naoki Kinoshita - Web page: https://patentgrep.com/patent/US5703469A ## 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 31/367: Software therefor, e.g. for battery testing using modelling or look-up tables - G01R 31/3828: using current integration - G01R 31/386: {using test-loads} - 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 - Y10S 320/21: State of charge of battery - 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) - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract Detected values of a voltage and a current of a battery which are supplied from a voltage and current detector are stored in a memory at a plurality of times while the battery is being discharged. A regression line calculator determines an internal resistance and an open-circuit voltage (non-load voltage or electromotive force) of the battery based on the detected values stored in the memory. Even when the battery is in use with the voltage and the current frequency varying while it is being discharged, a memory effect on the battery can be determined from a reduction in the open-circuit voltage and a deterioration of the battery can be determined from an increase in the internal resistance. ## Claims ### Claim 1 A system for determining conditions of a nickel-based secondary battery mounted as a power unit on an electrically propelled vehicle, comprising: a voltage sensor for detecting a voltage across the battery, a current sensor for detecting a current flowing from the battery to a load; a memory for storing the detected values of the voltage and current from said voltage sensor and said current sensor at a plurality of times while the battery is being discharged; and processing means for calculating an internal resistance and an open-circuit voltage of the battery based on the detected values stored in said memory, determining a deterioration of the battery based on the internal resistance, and determining a memory effect on the battery based on the open-circuit voltage. ### Claim 2 (depends on 1) A system according to claim 1, further comprising an indicator for indicating the deterioration of the battery and the memory effect on the battery when the deterioration of the battery and the memory effect on the battery are determined by said processing means. ### Claim 3 (depends on 1) A system according to claim 1, wherein said processing means comprises means for determining the internal resistance and the open-circuit voltage of the battery according to a regression line equation which is obtained based on the detected values stored in said memory. ### Claim 4 (depends on 1) A system according to claim 1, wherein said processing means comprises means for determining the internal resistance and an open-circuit voltage of the battery according to a regression line equation which is obtained based on the detected values stored in said memory, further comprising an indicator for indicating the deterioration of the battery and the memory effect on the battery when the deterioration of the battery and the memory effect on the battery are determined by said processing means. ### Claim 5 (depends on 1) A system according to claim 1, further comprising a discharged current integrator for integrating a discharged capacity of the battery, wherein said processing means comprises means for determining only the memory effect on the battery if the discharged capacity integrated by said discharged current integrator has not reached a predetermined discharged capacity, and determining both the deterioration of the battery and the memory effect on the battery if the discharged capacity integrated by said discharged current integrator has reached the predetermined discharged capacity. ### Claim 6 (depends on 1) A system according to claim 1, further comprising a temperature sensor for detecting a temperature of the battery, wherein said processing means comprises means for determining the deterioration of the battery based on the internal resistance with respect to the detected temperature by referring to a table of battery temperatures and non-deteriorated internal resistances which have been measured. ### Claim 7 (depends on 1) A system according to claim 1, further comprising a temperature sensor for detecting a temperature of the battery, wherein said processing means comprises means for determining the internal resistance according to a regression line equation which is obtained based on the detected values stored in said memory, and determining the deterioration of the battery based on the determined internal resistance with respect to the detected temperature by referring to a table of battery temperatures and non-deteriorated internal resistances which have been measured. ### Claim 8 (depends on 1) A system according to claim 1, wherein each of said plurality of times occurs at an interval of 1 second, and said processing means comprises means for calculating a regression line equation based on a plurality of detected values stored in said memory each time 60 sets of detected values are stored in said memory, and determining the internal resistance of the battery and the open-circuit voltage of the battery according to the calculated regression line equation. ### Claim 9 A system for determining conditions of a nickel-based secondary battery mounted as a power unit on an electrically propelled vehicle, comprising: a voltage sensor for detecting a voltage across the battery, a current sensor for detecting a current flowing from the battery to a load; a memory for storing the detected values of the voltage and current from said voltage sensor and said current sensor at a plurality of times while the battery is being discharged; and processing means for calculating an internal resistance of the battery based on the detected values stored in said memory, and determining a deterioration of the battery based on the internal resistance. ### Claim 10 (depends on 9) A system according to claim 9, wherein said processing means comprises means for determining the internal resistance of the battery according to a regression line equation which is obtained based on the detected values stored in said memory. ### Claim 11 (depends on 9) A system according to claim 9, further comprising a temperature sensor for detecting a temperature of the battery, wherein said processing means comprises means for determining the deterioration of the battery based on the internal resistance with respect to the detected temperature by referring to a table of battery temperatures and non-deteriorated internal resistances which have been measured. ### Claim 12 (depends on 9) A system according to claim 9, further comprising a temperature sensor for detecting a temperature of the battery, wherein said processing means comprises means for determining the internal resistance according to a regression line equation which is obtained based on the detected values stored in said memory, and determining the deterioration of the battery based on the determined internal resistance with respect to the detected temperature by referring to a table of battery temperatures and non-deteriorated internal resistances which have been measured. ### Claim 13 (depends on 9) A system according to claim 9, wherein each of said plurality of times occurs at an interval of 1 second, and said processing means comprises means for calculating a regression line equation based on a plurality of detected values stored in said memory each time 60 sets of detected values are stored in said memory, and determining the internal resistance of the battery according to the calculated regression line equation. ### Claim 14 A system for determining conditions of a nickel-based secondary battery mounted as a power unit on an electrically propelled vehicle, comprising: a voltage sensor for detecting a voltage across the battery, a current sensor for detecting a current flowing from the battery to a load; a memory for storing the detected values of the voltage and current from said voltage sensor and said current sensor at a plurality of times while the battery is being discharged; and processing means for calculating an open-circuit voltage of the battery based on the detected values stored in said memory, and determining a memory effect on the battery based on the open-circuit voltage. ### Claim 15 (depends on 14) A system according to claim 14, wherein said processing means comprises means for determining the open-circuit voltage of the battery according to a regression line equation which is obtained based on the detected values stored in said memory. ### Claim 16 (depends on 14) A system according to claim 14, wherein each of said plurality of times occurs at an interval of 1 second, and said processing means comprises means for calculating a regression line equation based on a plurality of detected values stored in said memory each time 60 sets of detected values are stored in said memory, and determining the open-circuit voltage of the battery according to the calculated regression line equation.