# US 11,906,597 B2 · Methods and systems for managing multi-cell batteries > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,906,597 B2 - Document ID: US11906597B2 - Status: Granted - Kind: B2 - Application number: 17/159,847 - Filed: 2021-01-27 - Published: 2021-05-20 - Granted: 2024-02-20 - Earliest claimed: 2017-11-15 - Assignees: Nova Semiconductor, Inc. - Applicants: Nova Semiconductor, Inc. - Inventors: Ahmad Ashrafzadeh - Web page: https://patentgrep.com/patent/US11906597B2 ## CPC - G01R 31/396: Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery - G01R 31/3835: involving only voltage measurements - H01M 10/425: {Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing (printed circuits H05K1/00)} - H01M 10/441: {for several batteries or cells simultaneously or sequentially} - H01M 10/482: {for several batteries or cells simultaneously or sequentially} - H01M 10/486: {for measuring temperature} - H01M 50/51: Connection only in series - H02J 7/52: for charge balancing, e.g. equalisation of charge between batteries - H02J 7/56: Active balancing, e.g. using capacitor-based, inductor-based or DC-DC converters - H02J 7/82: Control of state of charge [SOC] - H02M 7/1557: {with automatic control of the output voltage or current} - H03K 19/17784: for supply voltage - G01R 19/16542: {for batteries (charge condition monitoring in G01R31/36)} - 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 - 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 - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P) - H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M) - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract A resistor ladder comprising identical resistors is disposed electrically in parallel with a multicell battery to calibrate voltage-controlled oscillators or analog-to-digital convertors for voltage balancing the battery cells in the multicell battery. Switches in a first state provide the voltage across each resistor as inputs to the VCOs or ADCs. The number of oscillations of the output signal of each VCO or ADC over a predetermined time period are compared to determine an offset error. Switches in a second state provide the voltage across each battery cell as inputs to the VCOs or ADCs. The battery cells with a higher relative voltage can be discharged until they are balanced. Some aspects describe temperature-adjusted and interpolated determinations of electrical quantities in the cells such as voltage and/or current. ## Claims ### Claim 1 A system for determining battery cell voltages from a set of batteries connected in series, comprising: a plurality of first voltage controlled oscillators, each first voltage controlled oscillator configured to: receive a voltage value from a battery cell of a plurality of battery cells of the set of batteries; and convert the voltage value into an oscillating output signal; a plurality of digital level shifters, each digital level shifter configured to: receive the oscillating output signal from one of the plurality of first voltage controlled oscillators; and convert the oscillating output signal to a digital oscillating output signal; and digital circuitry configured to: receive the digital oscillating output signal from each of the plurality of digital level shifters; and calculate a voltage level from each battery cell of the plurality of battery cells based on the digital oscillating output signal, wherein the digital circuitry includes: a plurality of counters for receiving the digital oscillating output signals; and logic circuitry for calculating the voltage level based on count values from the plurality of counters and known electrical output values of the plurality of voltage controlled oscillators. ### Claim 2 (depends on 1) The system of claim 1, wherein the digital circuitry is further configured to control a discharge of the plurality of battery cells based on the calculated voltage level of each battery cell until the plurality of battery cells are uniformly charged or balanced. ### Claim 3 (depends on 1) The system of claim 1, further comprising at least one additional voltage controlled oscillator configured to receive a voltage output from a current sensor electrically connected to the set of batteries, wherein the voltage output from the current sensor indicates a current of at least one battery cell, and the digital circuitry is further configured to calculate a current of the at least one battery cell. ### Claim 4 (depends on 3) The system of claim 3, wherein the at least one additional voltage controlled oscillator is one of the plurality of first voltage controlled oscillators. ### Claim 5 (depends on 3) The system of claim 3, wherein the digital circuitry is further configured to: store a first set of known electrical outputs of an electrical quantity sensor obtained at a first temperature and a second set of known electrical outputs obtained at a second temperature; compute a pair of reference electrical output values corresponding to an operational temperature based on the first and second sets of known electrical outputs; and interpolate among the pair of computed reference electrical output values to determine a temperature-corrected electrical quantity. ### Claim 6 (depends on 5) The system of claim 5, wherein the first temperature is the same as the second temperature. ### Claim 7 (depends on 5) The system of claim 5, further comprising a temperature sensor configured to measure the operational temperature, and wherein the digital circuitry is further configured to receive the operational temperature from the temperature sensor. ### Claim 8 (depends on 5) The system of claim 5, wherein the digital circuitry is further configured to: compare the operational temperature to a temperature threshold; and control a charge or discharge of the plurality of battery cells based on the comparison of the operational temperature to the temperature threshold. ### Claim 9 (depends on 5) The system of claim 5, further comprising a machine learning system configured to receive the calculated voltage level, the current, and the operational temperature to determine a remaining charge in the set of batteries. ### Claim 10 (depends on 1) The system of claim 1, further comprising a machine learning system configured to control a charge, a discharge, and a balance the plurality of battery cells. ### Claim 11 (depends on 1) The system of claim 1, wherein the digital circuitry is further configured to determine relative voltage levels among the set of batteries. ### Claim 12 (depends on 1) The system of claim 1, wherein the calculated voltage level of each battery cell is compared against a set of preset values to control a discharge and a charge of the set of batteries based on the comparison of each battery cell against the set of preset values. ### Claim 13 (depends on 1) The system of claim 1, further comprising a resistor divider comprising a number of resistors connected across the set of batteries, the number of resistors equal to a number of batteries with substantially equal resistance values, each resistor comprising a voltage at its terminals equal to corresponding battery voltages in a balanced set of batteries. ### Claim 14 (depends on 13) The system of claim 13, wherein the plurality of first voltage controlled oscillators are further configured to: receive the battery voltages in one operation; receive a resistor voltage in a second operation; compare the battery voltage with the resistor voltage; and determine whether each battery cell is below or above a balanced voltage. ### Claim 15 (depends on 14) The system of claim 14, further comprising at least one switch configured to connect or disconnect the resistor divider from the set of batteries. ### Claim 16 (depends on 14) The system of claim 14, wherein at least one first voltage controlled oscillator of the plurality of first voltage controlled oscillators is further configured to measure a reference voltage in a third operation. ### Claim 17 (depends on 1) The system of claim 1, further comprising a temperature sensor configured to generate an output that is mapped to a voltage or current output at a given temperature, such that the output of the temperature sensor calibrates the voltage or the current. ### Claim 18 (depends on 1) The system of claim 1, wherein the digital circuitry is further configured to: calculate maximum and minimum battery voltage thresholds based on a reference voltage; control a charge of the set of batteries based on the maximum battery voltage threshold; and control a discharge of the set of batteries based on the minimum battery voltage thresholds. ### Claim 19 A system for determining battery cell voltages from a set of batteries connected in series, comprising: a plurality of analog-to-digital converters (ADCs), each ADC configured to: receive a voltage value from a battery cell of a plurality of battery cells of the set of batteries; and convert the voltage value into an oscillating output signal; a plurality of digital level shifters, each digital level shifter configured to: receive the oscillating output signal from one of the plurality of first voltage controlled oscillators; and convert the oscillating output signal to a digital oscillating output signal; and digital circuitry configured to: receive the digital oscillating output signal from each of the plurality of digital level shifters; and calculate a voltage level from each battery cell of the plurality of battery cells based on the digital oscillating output signal, wherein the digital circuitry includes: a plurality of counters for receiving the digital oscillating output signals; and logic circuitry for calculating the voltage level based on count values from the plurality of counters and known electrical output values of the plurality of ADCs.