# US 10,502,793 B2 · Nonlinear acoustic resonance spectroscopy (NARS) for determining physical conditions of batteries > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,502,793 B2 - Document ID: US10502793B2 - Status: Granted - Kind: B2 - Application number: 15/836,531 - Filed: 2017-12-08 - Published: 2018-06-14 - Granted: 2019-12-10 - Earliest claimed: 2016-12-09 - Assignees: The Regents of the University of California; Feasible, Inc. - Applicants: Feasible, Inc. - Inventors: Andrew Gaheem Hsieh; Barry James Van Tassell; Robert Charles Mohr; Anne Wilkinson; Jonathan Ajo-Franklin; Shaurjo Biswas - Web page: https://patentgrep.com/patent/US10502793B2 ## CPC - G01R 31/392: Determining battery ageing or deterioration, e.g. state of health - B60L 3/0046: {relating to electric energy storage systems, e.g. batteries or capacitors} - B60L 3/12: Recording operating variables {; Monitoring of operating variables} - B60L 58/10: for monitoring or controlling batteries - B60L 58/12: responding to state of charge [SoC] - B60L 58/16: responding to battery ageing, e.g. to the number of charging cycles or the state of health [SoH] - G01N 29/12: by measuring frequency or resonance of acoustic waves {(measuring frequency or resonant frequency of mechanical vibrations or acoustic waves in general G01H1/06, G01H3/04, G01H13/00; acoustic resonators G10K11/04; vibration or shock testing of structures G01M7/00)} - G01N 29/346: {with amplitude characteristics, e.g. modulated signal} - G01N 29/348: {with frequency characteristics, e.g. single frequency signals, chirp signals (measuring frequency of mechanical vibrations or acoustic waves in general G01H1/06, G01H3/04; measuring frequency or analysing frequency spectra G01R23/00)} - G01N 29/46: by spectral analysis, e.g. Fourier analysis {or wavelet analysis (spectral signal processing per se G06F17/14)} - G01R 31/3842: combining voltage and current measurements - G01R 31/385: Arrangements for measuring battery or accumulator variables (for monitoring G01R31/382) - G01R 31/389: Measuring internal impedance, internal conductance or related variables - 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) - H01M 10/486: {for measuring temperature} - B60L 2240/545: Temperature - G01N 2291/02491: Materials with nonlinear acoustic properties - G01N 2291/025: Change of phase or condition - G01N 2291/2698: Other discrete objects, e.g. bricks - G01R 31/367: Software therefor, e.g. for battery testing using modelling or look-up tables - H01M 2010/4271: {Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing} - Y02E 60/10: Energy storage using batteries - 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) - B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - 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 - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract Systems and methods of determining physical conditions of a battery, such as state of charge (SOC), state of health (SOH), quality of construction, defect, or failure state include driving two or more acoustic signals of two or more amplitudes, each acoustic signal having two or more frequencies, into the battery and detecting vibrations generated in the battery based on the two or more acoustic signals. Nonlinear response characteristics of the battery for the two or more acoustic signals are determined from the detected vibrations. The physical conditions of the battery are determined based at least in part on the nonlinear response characteristics, using nonlinear acoustic resonance spectroscopy (NARS) or nonlinear resonant ultrasound spectroscopy (NRUS). ## Claims ### Claim 1 A method of determining one or more physical conditions of a battery, the method comprising: driving two or more acoustic signals of two or more amplitudes, each acoustic signal having two or more frequencies, into the battery, wherein the two or more acoustic signals comprise corresponding two or more chirp signals, the two or more frequencies being the same and in the same frequency range for all of the two or more chirp signals; detecting vibrations generated in the battery based on the two or more acoustic signals; determining nonlinear response characteristics of the battery for the two or more acoustic signals, from the detected vibrations, wherein the nonlinear response characteristics of the battery for the two or more acoustic signals comprise two or more resonance frequencies corresponding to the two or more amplitudes of the two or more acoustic signals; determining a slope or curve between the two or more resonance frequencies; comparing the nonlinear response characteristics of the battery to a reference nonlinear response characteristics, based on comparing the slope or curve to a reference slope or curve; and determining one or more physical conditions of the battery based at least in part on comparing the nonlinear response characteristics. ### Claim 2 (depends on 1) The method of claim 1, wherein the one or more physical conditions comprise one or more of a state of charge (SOC), state of health (SOH), quality of construction, defect, or failure state. ### Claim 3 (depends on 1) The method of claim 1 comprising a nonlinear acoustic resonance spectroscopy (NARS) or nonlinear resonant ultrasound spectroscopy (NRUS) of the battery. ### Claim 4 (depends on 1) The method of claim 1 comprising generating the two or more acoustic signals based on two or more driving voltages, wherein the two or more amplitudes of the two or more acoustic signals cause two or more strain values applied to the battery. ### Claim 5 (depends on 1) The method of claim 1, wherein each of the two or more chirp signals is one of: an up-chirp two or more frequencies comprising monotonically increasing frequencies; or a down-chirp with two or more frequencies comprising monotonically decreasing frequencies. ### Claim 6 (depends on 1) The method of claim 1, wherein each of the two or more chirp signals is one of: a linear chirp with two or more frequencies comprising linearly varying frequencies; or a nonlinear chirp with two or more frequencies comprising a nonlinear function of frequencies, the nonlinear function comprising an exponential, logarithmic function. ### Claim 7 (depends on 1) The method of claim 1, further comprising varying a state of charge of the battery between a fully charged state and a fully discharged state. ### Claim 8 (depends on 1) The method of claim 1, comprising driving the acoustic signal by a driving transducer coupled to the battery and detecting the vibrations in a receiving transducer or accelerometer coupled to the battery. ### Claim 9 (depends on 8) The method of claim 8, comprising placing the driving transducer and the receiving transducer with respect to the battery based on desired excitation modes, wherein the placing includes disposing the driving transducer and the receiving transducer on opposite sides or edges of the battery. ### Claim 10 (depends on 9) The method of claim 9, wherein the placing includes disposing the driving transducer and the receiving transducer on the same side of the battery. ### Claim 11 (depends on 1) The method of claim 1, wherein the reference nonlinear response characteristics comprise nonlinear response characteristics of a reference battery based on vibrations caused by driving the two or more acoustic signals into the reference battery. ### Claim 12 (depends on 11) The method of claim 11, wherein the battery and the reference battery are different batteries. ### Claim 13 (depends on 12) The method of claim 12, wherein a state of charge (SOC) or voltage of the battery is different from a corresponding SOC or voltage of the reference battery. ### Claim 14 (depends on 12) The method of claim 12, wherein a state of charge (SOC) or voltage of the battery is equal to a corresponding SOC or voltage of the reference battery. ### Claim 15 (depends on 11) The method of claim 11, wherein the battery and the reference battery are the same battery, and wherein the battery and the reference battery have different states of health (SOHs). ### Claim 16 (depends on 15) The method of claim 15, wherein a state of charge (SOC) or voltage of the battery is different from a corresponding SOC or voltage of the reference battery. ### Claim 17 (depends on 15) The method of claim 15, wherein a state of charge (SOC) or voltage of the battery is equal to a corresponding SOC or voltage of the reference battery. ### Claim 18 An apparatus comprising: means for driving two or more acoustic signals of two or more amplitudes, each acoustic signal having two or more frequencies, into a battery, wherein the two or more acoustic signals comprise corresponding two or more chirp signals, the two or more frequencies being the same and in the same range for all of the two or more chirp signals; means for detecting vibrations generated in the battery based on the two or more acoustic signals; means for determining nonlinear response characteristics of the battery for the two or more acoustic signals, from the detected vibrations, wherein the nonlinear response characteristics of the battery for the two or more acoustic signals comprise two or more resonance frequencies corresponding to the two or more amplitudes of the two or more acoustic signals; determining a slope or curve between the two or more resonance frequencies; means for comparing the nonlinear response characteristics of the battery to a reference nonlinear response characteristics, based on comparing the slope or curve to a reference slope or curve; and means for determining one or more physical conditions of the battery based at least in part on comparing the nonlinear response characteristics. ### Claim 19 (depends on 18) The apparatus of claim 18, wherein the one or more physical conditions comprise one or more of a state of charge (SOC), state of health (SOH), quality of construction, defect, or failure state. ### Claim 20 (depends on 18) The apparatus of claim 18, comprising means for generating the two or more acoustic signals based on two or more driving voltages, wherein the two or more amplitudes of the two or more acoustic signals cause two or more strain values applied to the battery. ### Claim 21 (depends on 18) The apparatus of claim 18, further comprising means for varying a state of charge of the battery between a fully charged state and a fully discharged state. ### Claim 22 (depends on 18) The apparatus of claim 18, wherein the means for driving the two or more acoustic signals and the means for detecting the vibrations are disposed on opposite sides or edges of the battery or on the same side of the battery.