# US 12,334,762 B2 · Method and system for battery management including bypassing battery cells in a battery pack > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,334,762 B2 - Document ID: US12334762B2 - Status: Granted - Kind: B2 - Application number: 18/680,412 - Filed: 2024-05-31 - Published: 2024-12-19 - Granted: 2025-06-17 - Earliest claimed: 2023-06-13 - Assignees: Sol-Ark, LLC - Applicants: Sol-Ark, LLC - Inventors: Thomas Joseph Brennan - Web page: https://patentgrep.com/patent/US12334762B2 ## CPC - H02J 7/663: {using battery or load disconnect circuits (H02J9/002 takes precedence)} - H01M 10/425: {Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing (printed circuits H05K1/00)} - H01M 10/44: Methods for charging or discharging (circuits for charging H02J7/00) - H01M 10/46: Accumulators structurally combined with charging apparatus (circuits for charging H02J7/00) - H02J 7/54: Passive balancing, e.g. using resistors or parallel MOSFETs - H02J 7/82: Control of state of charge [SOC] - H01M 2010/4271: {Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing} - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY ## Abstract A system can include a battery pack with battery cell sections connected in series, where each of the battery cell sections includes a battery cell and a bypass switch. The system can also include a control circuit. The control circuit can determine a capacity of a particular battery cell in a particular battery cell section, determine that the capacity of the particular battery cell is less than a predefined threshold, and in response, execute a bypass sequence for the particular battery cell. The bypass sequence can involve determining a bypass period for which to bypass the particular battery cell based on the capacity of the particular battery cell, and transmitting a bypass signal to a drive circuit. The drive circuit can receive the bypass signal and responsively operate the bypass switch of the particular battery cell section to bypass the particular battery cell for the bypass period. ## Claims ### Claim 1 A control circuit comprising circuitry configured to: determine whether a capacity of a battery cell of a battery pack is less than a predefined threshold; in response to determining that the capacity of the battery cell is less than the predefined threshold, execute a bypass sequence for the battery cell, wherein the bypass sequence involves: determining, based on the capacity of the battery cell, a bypass period for which to bypass the battery cell; and transmitting a bypass signal configured to cause a battery cell section associated with the battery cell to be bypassed for the bypass period; determine that the bypass period for the battery cell has finished; and in response to determining that the bypass period for the battery cell has finished, execute an activation sequence for the battery cell, the activation sequence being configured to allow current flow to the battery cell. ### Claim 2 (depends on 1) The control circuit of claim 1, wherein the circuitry comprises a power control switch configured to be coupled between the battery pack and a power source for controlling current flow to the battery pack from the power source, and wherein the bypass sequence further comprises: prior to transmitting the bypass signal, transmitting an open signal for opening the power control switch to prevent current flow from the power source to the battery pack. ### Claim 3 (depends on 2) The control circuit of claim 2, wherein the open signal is a first open signal, and wherein the bypass sequence comprises: after transmitting the first open signal, transmitting a second open signal for opening a charging switch of the battery cell section to prevent current flow through the battery cell, the charging switch being positioned in series with the battery cell; after transmitting the second open signal, transmitting the bypass signal; and after transmitting the bypass signal, transmitting a close signal for closing the power control switch to allow current flow from the power source to the battery pack. ### Claim 4 (depends on 1) The control circuit of claim 1, wherein the bypass period is a portion of a duty cycle for charging the battery pack. ### Claim 5 (depends on 1) The control circuit of claim 1, wherein the activation sequence comprises: transmitting a first open signal for opening a power control switch to prevent current flow from a power source to the battery pack; after transmitting the first open signal, transmitting a second open signal for opening a bypass switch to prevent current from bypassing the battery cell; after transmitting the second open signal, transmitting a first close signal for closing a charging switch of the battery cell section to allow current flow through the battery cell, the charging switch being positioned in series with the battery cell; and after transmitting the first close signal, transmitting a second close signal for closing the power control switch to allow current flow from the power source to the battery pack. ### Claim 6 (depends on 1) The control circuit of claim 1, wherein the circuitry comprises: a startup relay configured to draw power from one or more battery cells in the battery pack to activate a boost circuit; the boost circuit, wherein the boost circuit is configured to generate a drive voltage that is larger than an input voltage to the boost circuit; and a drive circuit configured to apply the drive voltage to a bypass switch of the battery cell to close the bypass switch. ### Claim 7 (depends on 1) The control circuit of claim 1, wherein the circuitry comprises a monitoring circuit configured to measure a voltage across the battery cell, and wherein the control circuit is configured to determine the capacity of the battery cell based on the voltage. ### Claim 8 (depends on 1) The control circuit of claim 1, wherein the circuitry is further configured to: store voltages or charge states associated with the battery cell section over multiple charging cycles; and determine the bypass period based on the stored voltages or charge states. ### Claim 9 A method comprising: determining, by a control circuit, whether a capacity of a battery cell of a battery pack is less than a predefined threshold; in response to determining that the capacity of the battery cell is less than the predefined threshold, executing, by the control circuit, a bypass sequence for the battery cell, wherein the bypass sequence involves: determining, based on the capacity of the battery cell, a bypass period for which to bypass the battery cell; and transmitting a bypass signal configured to cause a battery cell section associated with the battery cell to be bypassed for the bypass period; determining, by the control circuit, that the bypass period for the battery cell has finished; and in response to determining that the bypass period for the battery cell has finished, executing, by the control circuit, an activation sequence for the battery cell, the activation sequence being configured to allow current flow to the battery cell. ### Claim 10 (depends on 9) The method of claim 9, wherein the bypass sequence further comprises: prior to transmitting the bypass signal, transmitting an open signal for opening a power control switch to prevent current flow from a power source to the battery pack. ### Claim 11 (depends on 10) The method of claim 10, wherein the open signal is a first open signal, and wherein the bypass sequence comprises: after transmitting the first open signal, transmitting a second open signal for opening a charging switch of the battery cell section to prevent current flow through the battery cell, the charging switch being positioned in series with the battery cell; after transmitting the second open signal, transmitting the bypass signal; and after transmitting the bypass signal, transmitting a close signal for closing the power control switch to allow current flow from the power source to the battery pack. ### Claim 12 (depends on 9) The method of claim 9, wherein the bypass period is a portion of a duty cycle for charging the battery pack. ### Claim 13 (depends on 9) The method of claim 9, wherein the activation sequence comprises: transmitting a first open signal for opening a power control switch to prevent current flow from a power source to the battery pack; after transmitting the first open signal, transmitting a second open signal for opening a bypass switch to prevent current from bypassing the battery cell; after transmitting the second open signal, transmitting a first close signal for closing a charging switch of the battery cell section to allow current flow through the battery cell, the charging switch being positioned in series with the battery cell; and after transmitting the first close signal, transmitting a second close signal for closing the power control switch to allow current flow from the power source to the battery pack. ### Claim 14 (depends on 9) The method of claim 9, further comprising: operating a startup relay to draw power from one or more battery cells of the battery pack during a startup phase of the battery pack to activate a boost circuit; operating the boost circuit to generate a drive voltage that is larger than an input voltage to the boost circuit; and operating a drive circuit to apply the drive voltage to a bypass switch of the battery cell to close the bypass switch. ### Claim 15 (depends on 9) The method of claim 9, further comprising: measuring a voltage across the battery cell; and determining the capacity of the battery cell based on the voltage. ### Claim 16 (depends on 9) The method of claim 9, further comprising: storing voltages or charge states associated with the battery cell over multiple charging cycles; and determining the bypass period based on the stored voltages or charge states. ### Claim 17 A method comprising: determining, by a first control circuit associated with a first battery pack, that a battery cell of the first battery pack is to be bypassed for a bypass period based on a capacity of the battery cell; and in response to determining that the battery cell is to be bypassed for the bypass period: executing, by the first control circuit, a first bypass sequence configured to bypass the battery cell for the bypass period; and transmitting, by the first control circuit, a bypass notification to a second control circuit associated with a second battery pack. ### Claim 18 (depends on 17) The method of claim 17, wherein the bypass period is a first bypass period, and wherein the second control circuit is configured to: receive the bypass notification; and based on receiving the bypass notification, execute a second bypass sequence to bypass another battery cell in the second battery pack for a second bypass period. ### Claim 19 (depends on 18) The method of claim 18, wherein the first bypass period is the same as the second bypass period. ### Claim 20 (depends on 9) The method of claim 9, wherein the method is performed during a battery charging phase. ### Claim 21 (depends on 17) The method of claim 17, wherein the bypass notification indicates the bypass period.