# US 11,079,437 B2 · Battery state-of-health determination upon charging using state-of-health classifier > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,079,437 B2 - Document ID: US11079437B2 - Status: Granted - Kind: B2 - Application number: 16/212,267 - Filed: 2018-12-06 - Published: 2019-06-06 - Granted: 2021-08-03 - Earliest claimed: 2017-12-06 - Applicants: Cadex Electronics Inc. - Inventors: Tina Shoa Hassani Lashidani - Web page: https://patentgrep.com/patent/US11079437B2 ## CPC - G01R 31/392: Determining battery ageing or deterioration, e.g. state of health - G01R 31/3648: {comprising digital calculation means, e.g. for performing an algorithm} - G01R 31/367: Software therefor, e.g. for battery testing using modelling or look-up tables - G01R 31/3835: involving only voltage measurements - H02J 7/865: {Battery or charger load switching, e.g. concurrent charging and load supply (H02J7/50 takes precedence)} - H02J 7/90: Regulation of charging or discharging current or voltage - 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 ## Abstract A rechargeable battery is charged and, at the same time, steps are taken to assess its state of health (SoH). The SoH is first broadly classified, which is only a coarse estimate. Next, the state of charge (SoC) is estimated, and then the SoC is repeatedly measured and predicted during charging until its value converges to a reliable value. The SoH is a state in the Kalman filter used for determining the SoC, and the SoH is also refined through the filter process. The SoH is reported when or after the SoC has converged, and is reported before charging is completed. ## Claims ### Claim 1 A method of determining state of health (SoH) of a battery comprising the steps of: classifying the battery into one of multiple SoH classifications; estimating an initial value of a state of charge (SoC) of the battery; starting to charge the battery; repeatedly measuring a voltage across terminals of the battery as the battery is charged; repeatedly predicting values of the voltage across the terminals using an extended Kalman filter, wherein the SoH is a state of the extended Kalman filter; repeatedly comparing the predicted values with the measured voltages; determining that a difference between the predicted values and the measured voltages is below a threshold; obtaining a value of the SoH from the extended Kalman filter. ### Claim 2 (depends on 1) The method of claim 1 comprising obtaining a converged value (SoCC) of the SoC from the repeated measurements, wherein the SoCC is obtained when said difference is below the threshold. ### Claim 3 (depends on 1) The method of claim 1 wherein classifying the battery comprises: applying a discharging or charging current pulse to the battery; and measuring a voltage response of the battery to the pulse; wherein the classification of the battery depends on the voltage response. ### Claim 4 (depends on 1) The method of claim 1, wherein the classifications are good (SoH>90%), medium (SoH 70-90%) and poor (SoH<70%). ### Claim 5 (depends on 1) The method of claim 1, wherein the battery is fully discharged when the initial value of the SoC is estimated. ### Claim 6 (depends on 1) The method of claim 1, wherein estimating the initial value of the SoC comprises: measuring an open circuit voltage (OCV) of the battery to result in value V; and using V to determine the initial value by accessing a relationship between the OCV and SoC, the relationship being specific to the classification of the battery. ### Claim 7 (depends on 6) The method of claim 6, wherein the relationship is defined by a 10th order polynomial. ### Claim 8 (depends on 7) The method of claim 7, wherein the 10th order polynomial represents an average of OCV and SoC data measured during charging and discharging the battery or another battery that is comparable to the battery. ### Claim 9 (depends on 1) The method of claim 1, comprising continuing to charge the battery after obtaining the value of the SoH. ### Claim 10 (depends on 1) The method of claim 1, wherein the voltage across the terminals is predicted using an electric circuit model of the battery, a current supplied to the battery and a 10th order polynomial relationship between the OCV and SoC. ### Claim 11 (depends on 10) The method of claim 10, comprising: measuring a temperature of the battery; and adjusting a parameter of the electrical circuit model in response to the temperature. ### Claim 12 (depends on 1) The method of claim 1, wherein the difference is a root mean square difference of multiple sequential comparisons of the predicted values and the measured values. ### Claim 13 A battery charger for determining state of health (SoH) of a battery comprising: a battery interface that connects to the battery; a user interface; a processor connected to the battery interface and the user interface; a computer readable memory storing computer readable instructions, which, when executed by the processor, cause the battery charger to: classify the battery into one of multiple SoH classifications; estimate an initial value of a state of charge (SoC) of the battery; start to charge the battery; repeatedly measure a voltage across terminals of the battery as the battery is charged; repeatedly predict values of the voltage across the terminals using an extended Kalman filter, wherein the SoH is a state of the extended Kalman filter; repeatedly compare the predicted values with the measured voltages; determine that a difference between the predicted values and the measured voltages is below a threshold; obtain a value of the SoH from the extended Kalman filter; and output the calculated value of the SoH on the user interface. ### Claim 14 (depends on 13) The battery charger of claim 13, wherein the battery interface is a battery adapter and the extended Kalman filter is stored in the battery adapter. ### Claim 15 (depends on 13) The battery charger of claim 13, further comprising an interface to an internet-based server, wherein the extended Kalman filter is stored on the server. ### Claim 16 (depends on 13) The battery charger of claim 13, configured to obtain a converged value (SoCC) of the SoC from the repeated measurements, wherein the SoCC is obtained when said difference is below the threshold. ### Claim 17 (depends on 13) The battery charger of claim 13, wherein the battery charger classifies the battery by: applying a discharging or charging current pulse to the battery; and measuring a voltage response of the battery to the pulse; wherein the classification of the battery depends on the voltage response. ### Claim 18 (depends on 13) The battery charger of claim 13, wherein the battery charger estimates the initial value of the SoC by: measuring an open circuit voltage (OCV) of the battery to result in value V; and using V to determine the initial value by accessing a 10th order polynomial relationship between the OCV and SoC, the relationship being specific to the classification of the battery. ### Claim 19 (depends on 13) The battery charger of claim 13, wherein the extended Kalman filter includes an electric circuit model of the battery. ### Claim 20 (depends on 13) The battery charger of claim 13, wherein the battery charger is an ultra-fast charger and configured to control a rate of charging using the value of the SoH obtained during charging.