# US 8,788,225 B2 · Cell diagnostic system and method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,788,225 B2 - Document ID: US8788225B2 - Status: Granted - Kind: B2 - Application number: 12/999,587 - Filed: 2009-06-24 - Published: 2011-07-14 - Granted: 2014-07-22 - Earliest claimed: 2008-06-27 - Assignees: Johnson Controls - SAFT Advanced Power Solutions LLC - Applicants: Steven J. Wood; Emmanuel Maubert; Olivier Veglio - Inventors: Steven J. Wood; Emmanuel Maubert; Olivier Veglio - Web page: https://patentgrep.com/patent/US8788225B2 ## CPC - G01R 31/3835: involving only voltage measurements - G01R 31/396: Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery - G01R 19/0084: {Measuring voltage only} - H02J 7/585: {Sequential battery discharge in systems with a plurality of batteries} - H02J 7/82: Control of state of charge [SOC] - 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) - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A system for assessing the accuracy of an electrochemical cell voltage measurement includes a cell discharge circuit electrically coupled to at least one electrochemical cell and configured to partially discharge the at least one cell when the cell discharge circuit is activated, and a cell measurement circuit electrically coupled to the at least one cell and to the cell discharge circuit. The cell measurement circuit is configured to measure a voltage of the at least one cell before activation of the cell discharge circuit and after activation of the cell discharge circuit. The cell measurement circuit compares the voltage before activation of the cell discharge circuit to the voltage after activation of the cell discharge circuit to detect if an error in the voltage measurement occurred. ## Claims ### Claim 1 A system for assessing the accuracy of an electrochemical cell voltage measurement, comprising: a cell discharge circuit electrically coupled to an electrochemical cell and configured to at least partially discharge the cell when the cell discharge circuit is activated; a cell measurement circuit electrically coupled to the at least one cell and to the cell discharge circuit, the cell measurement circuit configured to measure a voltage of the at least one cell before activation of the cell discharge circuit and after activation of the cell discharge circuit, wherein the cell measurement circuit compares the voltage before activation of the cell discharge circuit to the voltage after activation of the cell discharge circuit to detect if an error in the voltage measurement occurred. ### Claim 2 (depends on 1) The system of claim 1, wherein the cell measurement circuit is configured to detect an error if the voltage before activation of the cell discharge circuit is equal to the voltage after activation of the cell discharge circuit. ### Claim 3 (depends on 2) The system of claim 2, wherein the cell measurement circuit is configured to detect an error if a sense line to the at least one cell is broken. ### Claim 4 (depends on 1) The system of claim 1, wherein the cell measurement circuit is configured to send a signal to a battery management system if an error is detected. ### Claim 5 (depends on 1) The system of claim 1, wherein the cell discharge circuit is electrically coupled to the at least one cell in parallel. ### Claim 6 (depends on 5) The system of claim 5, wherein the cell measurement circuit is electrically coupled to the cell discharge circuit in parallel. ### Claim 7 (depends on 1) The system of claim 1, wherein the cell discharge circuit comprises a resistor configured for balancing the voltage of the at least one cell to match the voltage of other cells in a battery system and a transistor configured to act as a switch to activate the cell discharge circuit. ### Claim 8 (depends on 7) The system of claim 7, wherein the cell measurement circuit comprises a microcontroller. ### Claim 9 (depends on 8) The system of claim 8, wherein the microcontroller is electrically coupled to the transistor of the cell discharge circuit in order to activate the cell discharge circuit. ### Claim 10 A method for assessing the accuracy of an electrochemical cell voltage measurement, comprising: measuring a first voltage of at least one electrochemical cell using a cell measurement circuit electrically coupled to the at least one cell; activating a cell discharge circuit electrically coupled to the at least one cell to at least partially discharge the at least one cell; measuring a second voltage of the at least one cell after activation of the cell discharge circuit; and comparing the first voltage to the second voltage to determine if there is an error in the voltage measurement of the at least one cell. ### Claim 11 (depends on 10) The method of claim 10, wherein the cell measurement circuit is configured to detect an error if the first voltage is equal to the second voltage. ### Claim 12 (depends on 11) The method of claim 11, wherein the cell measurement circuit is configured to detect an error if a sense line to the at least one cell is broken. ### Claim 13 (depends on 10) The method of claim 10, wherein the cell measurement circuit is configured to send a signal to a battery management system if an error is detected. ### Claim 14 (depends on 10) The method of claim 10, wherein the cell discharge circuit is electrically coupled to the at least one cell in parallel. ### Claim 15 (depends on 14) The method of claim 14, wherein the cell measurement circuit is electrically coupled to the cell discharge circuit in parallel. ### Claim 16 (depends on 10) The method of claim 10, wherein the cell discharge circuit comprises a resistor configured for balancing the voltage of the at least one cell to match the voltage of other cells in a battery system. ### Claim 17 (depends on 16) The method of claim 16, wherein the cell discharge circuit further comprises a transistor configured to act as a switch in order to activate the cell discharge circuit. ### Claim 18 (depends on 10) The method of claim 10, wherein the cell measurement circuit comprises a microcontroller. ### Claim 19 (depends on 18) The method of claim 18, wherein the microcontroller is electrically coupled to the transistor of the cell discharge circuit in order to activate the cell discharge circuit. ### Claim 20 A method for assessing the accuracy of an electrochemical cell voltage measurement, comprising: providing a cell measurement circuit electrically coupled to at least one cell; providing a cell discharge circuit electrically coupled to the at least one cell and configured to partially discharge the at least one cell when activated; measuring a first voltage of the at least one cell using the cell measurement circuit; activating the cell discharge circuit to partially discharge the at least one cell; measuring a second voltage of the at least one cell after activation of the cell discharge circuit; comparing the first voltage to the second voltage to determine if there is an error in the voltage measurement of the at least one cell.