Enhanced single cell energy management system

Abstract

A battery system is provided having a first battery cell and a second battery cell within a battery pack. A first battery management system (BMS) may be in communication with the first battery cell, while a second battery management system may be in communication with the second battery cell. In this manner, each BMS may function to locally control a respective battery cell, thereby improving control over each cell. The BMS may include a controller configured to receive battery cell measurement data, process the battery cell measurement data, and then generate control signals based on the battery cell measurement data. The control signals may be provided to switching circuits connected to the battery cells, thereby enabling individualized control of each battery cell. Furthermore, each BMS may share information about the individual cells it monitors with other BMSs. Because each battery cell may be associated with its own BMS, improved manufacturability, flexibility, and safety may be achieved, among other advantages.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application Nos. 63 / 479,818, filed January 13, 2023, 63 / 581,999, filed September 12, 2023, 63 / 595,387, filed November 2, 2023, and 63 / 605,234, filed December 1, 2023. The entire contents of each priority application are incorporated herein by reference.

[0002] The subject matter described herein generally relates to systems and methods incorporated into energy storage systems. More particularly, the subject matter described herein relates to management systems for monitoring and controlling energy storage systems such as batteries. [Background technology]

[0003] Renewable energy sources, such as solar and wind power, which are essential for addressing climate change, often rely heavily on battery technology. Such energy storage systems (ESS) are central to ensuring a stable and resilient power supply from intermittent renewable sources. However, such energy storage systems often face safety, performance, and flexibility concerns.

[0004] One example that is enabling a sustainable transition to renewable resources is electric vehicles (EVs), which have emerged as a key solution for addressing one of the largest causes of climate pollution. Technologies related to energy storage systems such as batteries are fundamental to the electrification of transportation, with hundreds of billions of dollars being poured into research and development related to battery chemistries. Nevertheless, incidents of battery fires and electric vehicle recalls continue to highlight suboptimal safety and performance issues in the industry.

[0005] A key part of the safety, performance, and flexibility of these various energy storage systems are the subsystems that provide management and control. For example, the battery management system (BMS) is a key component in modern energy storage and electric vehicle systems, playing a vital role in ensuring optimal performance, safety, and service life of rechargeable batteries. At its core, the BMS is an electronic system that monitors and manages critical parameters of the battery pack. By continuously collecting and analyzing data from the cells in the battery, the BMS can, for example, adjust the charge balance between cells in real time, prevent overcharging or over-discharging, and regulate temperature to avoid thermal issues. Summary of the Invention

[0006] The subject matter described herein addresses many of the shortcomings associated with conventional energy management systems by providing a management system at the cell level instead of the system level. For example, unlike conventional battery management systems that process information from multiple battery cells simultaneously and control all of those energy storage cells from a single BMS unit, in some aspects, the systems and methods described herein provide individual BMS units associated with each energy storage cell. In this way, each battery cell can become a “smart” battery cell that can actively read, monitor, and control energy flow rather than being a passive container of its chemical makeup, eliminating the need for a central BMS system. Each single-cell BMS unit can further have bidirectional communication capabilities with other single-cell BMS units within the same battery pack, which can provide benefits such as more advanced monitoring and control, improved device intelligence, more accurate and real-time state of charge (SOC) and state of health (SOH) measurements, optimized safety, improved reliability and redundancy, and increased performance and flexibility, among others. With this new management electronics design, battery cells are no longer passive containers of chemical makeup that simply generate energy, but actively read, monitor, and control energy flow and communicate bidirectionally between cells, exponentially improving safety, performance, and flexibility. Another potential advantage is that, unlike many conventional systems that lack the capability to measure the SoC and SoH of specific cells within an operating battery pack, the single-cell BMS of the systems and methods described herein may also house sensors that measure internal changes within connected cells that affect the SoC and SoH. This allows for real-time monitoring of the SoC and SoH, improving detection time and accuracy.

[0007] This distributed single-cell BMS arrangement also enables unique battery configurations and functionality that cannot be easily implemented using conventional BMS designs. For example, because each battery cell and single-cell BMS unit can effectively operate as a standalone unit, a modular approach can be easily adopted when designing new battery systems. Specifically, for example, because each single-cell BMS system can be pre-programmed to pair with various battery structures and chemistries, system designers can easily combine any appropriate number of battery cell units with each other (including units having different voltages, energy capacities, and / or chemistries). Furthermore, because each single-cell BMS can control the circuitry connecting the individual battery cells, the unique circuit control can provide extended battery life, charging flexibility, and improved safety (e.g., by simultaneously disconnecting individual cells). Furthermore, the proximity of the single-cell BMS systems to the individual cells can improve accuracy when monitoring battery cell variables, facilitating system noise reduction. The single cell BMS can also advantageously receive information from other connected single cell BMSs and utilize artificial intelligence algorithms to process such information to further improve cell control, performance, and safety event recognition.

[0008] In one aspect, the present disclosure provides a battery system. The battery system may include a first battery cell in a battery pack and a first battery management system (BMS) in communication with the first battery cell. The first BMS may include a first controller configured to receive measurement data from the first battery cell, process the first battery cell measurement data, and generate a control signal based on the processed measurement data from the first battery cell. The battery system may also include a second battery cell in the battery pack and a second BMS in communication with the second battery cell. The second BMS may include a second controller configured to receive measurement data from the second battery cell, process the second battery cell measurement data, and generate a control signal based on the processed measurement data from the second battery cell.

[0009] In another aspect, the present disclosure provides a battery system that may include a first battery management system (BMS) including a first switching circuit configured to control connectivity of a first battery cell in a battery pack. The battery system may include a second BMS including a second switching circuit configured to control connectivity of a second battery cell in the battery pack.

[0010] In another aspect, the present disclosure provides a battery unit. The battery unit may include battery cells and a housing enclosing the battery cells. The housing may be configured to provide electrical access between the battery cells and at least one battery cell not contained within the housing. The battery unit may also include a battery management system (BMS) coupled to the enclosure and in communication with the battery cells. The BMS may include a controller configured to receive measurement data of the battery cells, process the battery cell measurement data, and generate control signals based on the processed measurement data from the battery cells.

[0011] The details of one or more variations of the subject matter described herein are set forth in the accompanying drawings and the description below. Other features and advantages of the subject matter described herein will be apparent from the description and drawings, and from the claims. [Brief explanation of the drawings]

[0012] [Figure 1A] 1 illustrates a battery system including three battery cells connected in circuit and three respective battery management systems according to one embodiment of the present disclosure.

[0013] [Figure 1B] 1B illustrates the battery system of FIG. 1A, showing the internal circuitry and components of each of the three respective battery management systems in greater detail.

[0014] [Figure 2] 1 illustrates a portion of a battery system including battery cells and a corresponding battery management system according to one aspect of the disclosure.

[0015] [Figure 3A] 1 illustrates a battery cell and a switching circuit of a battery management system corresponding to the battery cell, according to one aspect of the present disclosure.

[0016] [Figure 3B] 3B illustrates the battery cell of FIG. 3A shown operating with duty cycle control and switching circuitry according to one embodiment of the present disclosure.

[0017] [Figure 4] 1 illustrates various modes of operation for a switching circuit of a battery management system according to one aspect of the present disclosure.

[0018] [Figure 5] 1 illustrates a controller for a battery management system according to one aspect of the present disclosure.

[0019] [Figure 6] 1 illustrates various connection types of a bidirectional communication interface of a battery management system according to aspects of the present disclosure.

[0020] [Figure 7] 1 illustrates various multi-cell configurations compatible with a battery management system according to aspects of the present disclosure.

[0021] [Figure 8] 1 illustrates a battery unit according to one aspect of the present disclosure.

[0022] [Figure 9A] 1 illustrates a battery system having multiple battery cell chemistries and capacities in a fully charged state according to one aspect of the present disclosure.

[0023] [Figure 9B] 9B illustrates the battery system of FIG. 9A in a partially discharged state, according to one embodiment of the present disclosure.

[0024] [Figure 9C] 9A-9B in a partially charged state, according to one embodiment of the present disclosure.

[0025] [Figure 10A] 1 illustrates a battery system fully charged from an 800V charger according to one embodiment of the present disclosure.

[0026] [Figure 10B] 10B illustrates the battery system of FIG. 10A connected to a 400V charger with half of the battery cells fully charged and the other half fully discharged and bypassed in the circuit, according to one embodiment of the present disclosure.

[0027] [Figure 11] 1 illustrates a method for controlling a battery system according to one aspect of the present disclosure.

[0028] [Figure 12] 1 illustrates a method for charging a battery system according to one aspect of the present disclosure.

[0029] [Figure 13] 1 illustrates a method of manufacturing a battery system, according to an aspect of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0030] The subject matter of the present disclosure will be better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings, which form a part hereof.

[0031] As used herein, a "battery pack," unless the context dictates otherwise, may generally refer to at least two battery cells electrically connected in series, parallel, or a mixture of both. The individual battery cells may be connected using a battery pack circuit that may be electrically connected with a device (e.g., an electric vehicle) and configured to provide power to the device (e.g., an electric vehicle). As used herein, a "battery circuit," unless the context dictates otherwise, may generally refer to a single battery cell electrically connected with a single battery management system. Thus, as used herein, a "battery pack" may include multiple battery cells electrically connected to each other, and each battery cell may be part of its own individual battery circuit with an associated battery management system.

[0032] As mentioned above, many commercial energy systems, such as batteries, rely on management systems for safety and control. A typical battery management system (BMS) is designed at the system or "pack" level with long wire connections between a single central processing unit and sensor components, which may be located on the battery cells. In other words, the BMS acts as a central hub, providing monitoring and control of all battery cells simultaneously. This disclosure recognizes that this typical configuration has many drawbacks. For example, long wire connections can introduce complexity into BMS design because measurement accuracy issues often arise due to parasitic impedances in the wires and noise sensitivity (i.e., signal pickup generated by electric fields) caused by the wires. These long-wire measurement latency and accuracy issues can often lead to serious safety issues. Furthermore, each BMS must be tailored to the specific type, quantity, and size of the battery packs it controls, thereby preventing easy expansion or replacement of battery pack configurations without reconfiguring the BMS. Furthermore, typical BMS systems rely on high-level control operations of battery cells rather than cell-by-cell control, making bypassing individual cells infeasible, although it may be advantageous in some situations.

[0033] The present disclosure recognizes that these shortcomings, along with the complexities of battery operation, diverse chemistries, and varying usage patterns, require more advanced monitoring and control, increased device intelligence, and more accurate measurement of state of charge ("SOC") and state of health ("SOH"). Accordingly, the present disclosure provides systems and methods for energy management systems (e.g., BMS) that function at the cell level (e.g., battery cells), improving cell monitoring and control and providing additional functional benefits to the overall system that may not typically be possible when relying on a centralized BMS. In other words, each cell is transformed into a "smart" energy storage vessel that actively reads, monitors, and controls energy flow.

[0034] While the systems and methods described herein are primarily illustrated by way of example in terms of battery management systems, it should be readily understood that the teachings described herein are applicable to any suitable energy storage system, including, but not limited to, capacitors, supercapacitors, fuel cells, and other energy systems that may benefit from local control of the energy cells in use. It should further be understood that the systems and methods of the present disclosure enable various combinations of these energy storage systems (e.g., supercapacitors in circuit with battery cells).

[0035] FIG. 1A illustrates a battery system 100 including three battery cells 111, 121, and 131, all electrically connected within a battery pack circuit 101, and three respective battery management systems 110, 120, and 130. A first BMS 110 may function to monitor and control the first battery cell 111, a second BMS 120 may function to monitor and control the second battery cell 121, and a third BMS 130 may function to monitor and control the third battery cell 131. In this manner, each battery cell 111, 121, and 131 is provided with its own localized BMS system. The battery systems may have positive and negative terminals and may function to supply and receive electrical energy as needed. For example, the battery pack circuit 101 may be configured to connect to an electrical load (e.g., an electric vehicle, a power grid, a home, etc.) and may be configured to provide electrical output energy. Similarly, the battery cells 111, 121, 131 may be rechargeable, and the battery pack circuit 101 may be configured to connect to a charger source, which may provide electrical energy to the battery cells 111, 121, 131. In this depiction, the three battery cells 111, 121, 131 are connected in series, although it should be readily understood that various additional circuit configurations may be utilized with any suitable number of battery cells and their respective BMSs.

[0036] 1A, showing in greater detail the internal circuitry and components of each BMS 110, 120, 130. As will be described further, each of the BMSs 110, 120, 130 may include various components for monitoring and controlling the battery cells 111, 121, 131. For example, each BMS 110, 120, 130 may include a controller 114, 124, 134, a switching circuit 112, 122, 132, and a communication interface 116, 126, 136, the functionality of each of which is described further herein.

[0037] FIG. 2 illustrates a portion of a battery system including a battery cell 211 and an associated battery management system 200 (included within a dashed line in this depiction). The battery management system 200 may include a positive terminal 216 and a negative terminal 218 as part of an electrical circuit to which the battery cell 211 may be connected. The BMS 200 may include various components, including, but not limited to, a switching circuit, which may include a switch controller 210 configured to regulate a cell switch 212 and a bypass switch 214. The switching circuit may be configured to safely connect, disconnect, bypass, short, and / or partially connect the battery cells during operation. A cell controller 220 may be in electrical communication with the switch controller 210 and configured to receive measurement data of the battery cell 211. This data may be provided to the cell controller 220 using several sensor components. For example, as shown, a voltage sensor 222, a temperature sensor 224, and multiple current sensors 226, 228 may all provide measurement data to the controller 220 to enable active monitoring of the battery cell 211. Among other benefits, the in-situ measurement (sensing) architecture of the BMS 200 may provide better detection of early signs of battery degradation and failure while improving performance, reliability, and safety. The controller 220 may be configured to process the measurement data of the first battery cell 211 and, in response to these inputs, take specific actions, including generating control signals that may be provided to the switch controller 210 to modify the state of the switches 212, 214 (e.g., open or close one or both switches). The BMS may also include a bidirectional communication interface (BCI) 230 in electrical communication with the cell controller 220 and the switching circuitry. The BCI may be configured to provide and receive communication signals to other BMSs, to internal battery system components, or to external systems. In this depiction, the BCI 230 may rely on a communication port 232 when providing communication signals to other BMSs.

[0038] 3A-3B illustrate battery cells and switching circuitry of a battery management system associated with the battery cells in various arrangements, including duty-cycled (FIG. 3B). Generally, a switch controller 310 may be configured to connect and disconnect the battery cell 301 from the battery pack (i.e., from the battery pack circuitry used to supply electrical energy to a connected device or system). The switch controller 310 may change the connection to the battery cell 301 upon receiving a control signal, such as a signal provided from a BMS (not shown), based on processed battery cell measurement data. For example, a controller in the BMS system may be configured to process the battery cell measurement data to determine whether the battery cell 301 is experiencing a critical condition and provide a control signal to the switch controller 310 only if the first battery cell is actually experiencing a critical condition. Using this localized switching circuitry, the battery cell 301 may be isolated from the battery pack circuitry (i.e., the circuitry may bypass the battery cell 301 but otherwise function normally) or completely disconnected in response to a control signal received by the switch controller 310. To accomplish this function, the switching circuit may include both a cell switch 312 configured to control an electrical connection between the first battery cell 301 and the battery pack circuit, and a bypass switch 314 configured to control an electrical connection on an electrical path of the battery pack circuit that bypasses the first battery cell. Although not shown in FIGS. 3A-3B , it should be readily understood that the cell switch 312 may alternatively be located on the negative terminal side of the battery cell 301. Similarly, while the cell switch 312 and the bypass switch 314 are shown in the individual battery circuits connecting the battery cells 301 to the BMS, it should be understood that these components may alternatively be located elsewhere so long as similar functionality is achieved.

[0039] Figure 4 illustrates various operating modes of the switching circuitry of a battery management system. As shown, the switching circuitry can be configured to connect (cell switch closed, bypass switch open), bypass (cell switch open, bypass switch closed), short (both cell switch and bypass switch closed), and / or disconnect (both cell switch and bypass switch open) the battery cells. As will be further described, this localized switching circuit control can provide many safety and performance benefits to the entire battery system. For example, active balancing of battery cells can be monitored and controlled using cell controllers and performed either when charging or discharging battery cells simply by actively adjusting the switching circuitry. This balancing may improve battery cell charge rate and maximum energy storage, minimize capacity mismatch during operation, and minimize charge cycles. Similarly, when the battery pack is not in use, each battery cell may be disconnected from each other at a local level (rather than simply disconnecting portions of the overall circuit), which can help prevent and contain dangerous battery events (e.g., unattended fires). Furthermore, if a battery cell is determined to be defective (i.e., no longer functional), the switching circuitry may allow the cell to simply be bypassed while still allowing the use of other functioning cells in the battery system. Any suitable electrical switching circuit components may be used to provide this functionality. Furthermore, it should be understood that other switching circuit configurations beyond these examples may be used to provide this localized control.

[0040] 5 illustrates a cell controller 520 of a battery management system. The controller 520 may include various components that enable functions such as receiving measurement data (i.e., cell telemetry) from cell sensors, processing this measurement data, storing this processed measurement data, communicating this measurement data to other BMSs, and providing control signals to switch circuits or other BMSs. In this manner, the cell controller 520 may act as the "brains" of the local BMS, enabling real-time processing and control of the battery cells.

[0041] As shown, cell controller 520 may receive various inputs, including measurement data for local cell voltage 522, local cell temperature 524, local cell current 526, as well as other local cell data 528 (e.g., data from one or more additional sensors). This measurement data may be received as signals at telemetry monitor 540. Telemetry monitor 540 may accurately collect analog and digital information from the battery cells with which the BMS is associated and digitize the collected information (e.g., convert cell voltage, cell charge / discharge current, and temperature using an analog-to-digital converter (ADC) and internal voltage reference). Telemetry monitor 540 may then forward the digitized information to different functional sections within cell controller 520.

[0042] The data interface 550 may be used to transfer information from adjacent (or all) BMSs in the battery system to different functional sections within the controller 520 of each BMS. For example, the data interface 550 may receive information 510 from the bidirectional communication interface of each BMS, including, but not limited to, cell measurement data and status information from other BMSs in the battery system, cell ID / authentication data from other BMSs in the battery system, and cell state of health (SoH) and state of charge (SoC) from other BMSs in the battery system. Additionally, the data interface may receive characteristic information of other battery cells in the battery system, such as cell characteristic curves, allowed operating ranges of the cells, cell ID / serial numbers, and cell chemistry types.

[0043] The controller 520 may include various processing sections (contained within one or more microprocessors or microcontrollers) that may rely on algorithms to determine the SoC and SoH of the local battery cell based on information provided by the telemetry monitor 540, the data interface 550, cell history memory storage 554 within the controller, and the system memory 556. For example, the SoC and SoH calculation 552 may be based on variables such as, but not necessarily limited to, cell voltage, cell current, coulomb count (during charging or discharging), temperature, extraction impedance, cell history, hysteresis behavior, and cell parameters and characteristic transfer functions (i.e., SoC and SoH flow charts) published by the battery cell manufacturer of the local battery cell. The SoC and SoH of other battery cells in the battery system may also be determined by the controller 520 based on information provided by other BMSs, which may allow for improved redundancy and validation of any SoC or SoH calculations by the other BMSs.

[0044] The cell history memory storage 554 may be configured to store and track information about the local battery cells of the BMS with which the controller 520 is associated. The cell history memory storage 554 may store information such as the battery chemistry type, battery identification number, cell capacity, change in cell capacity over time, timestamp of charge or discharge activity using coulomb integration (charge / discharge current and duration), charge rate information, maximum / typical / minimum cell voltage and cell temperature and cell charge / discharge current, cell impedance and maximum power delivery, start of service (formation timestamp), charge cycle count, charge rate and health history for the local battery cells.

[0045] The data contained in the cell history memory storage 554 can be used to compare cell history data of other BMSs (and therefore all cells) in the stack, thereby increasing the predictability of the lifespan of the entire battery system and the local battery cell. The data contained in the cell memory storage 554 and / or the system memory 556 can continue to adaptively increase in accuracy as more data is iteratively collected and updated by the controller 520. For example, the information in the cell history memory storage 554, along with the latest updated SoC and SoH calculations, can be used to continuously update the control and operation of the BMS. The system memory 556 can serve as general storage of information measured, transferred, calculated, processed, and / or generated by the BMS. For example, SoC / SoH calculation results and memory storage to support embedded software / firmware are examples of items that can be stored in the general system memory 556. The cell history memory storage 554 can include information about the characteristics of the local memory cells, such as their cell characteristic curves, their allowable operating ranges, their capacities, their cell IDs / serial numbers, and their cell chemistry types.

[0046] The embedded software / firmware processing (ESP) 558 may be used to extract, calculate, and process information within an individual BMS. The primary function of the ESP 558 may be to keep the BMS operating safely and reliably. The ESP 558 may be iteratively modified by ESP programming for optimal operation, such as switching circuit control as described above, or the ESP 558 may operate autonomously without user intervention to protect the BMS from various faults (i.e., momentary failures) or latent fault conditions (i.e., gradual damage). The ESP 558 may be designed to continuously identify, monitor, and update the charge capacity, state of charge, and cell history of local battery cells (including cell SoC and SOH).

[0047] As described above, the controller 520 may be configured to continuously monitor cell parameters for indications of degradation or patterns to prevent further degradation (i.e., improving SOH) or catastrophic failure (e.g., thermal runaway due to rising impedance). In other words, the controller 520 may use the processed cell measurement data, cell history data, and measurement and cell history data provided by other BMSs to generate various command signals that may be provided to the switching circuitry 530. For example, the controller 520 may be configured to determine whether a temperature range or operating voltage range of a local battery cell has been exceeded, and if so, generate a control signal to (i) disconnect the first battery cell so that the battery pack circuitry bypasses the first battery cell, or (ii) disconnect the entire battery pack circuitry. In some embodiments, the controller 520 may also provide communication signals to the switching circuitry of other BMSs or to external devices (e.g., automobile management systems, personal communication devices such as cell phones or tablets, etc.). For example, if the controller 520 determines that a battery cell is approaching a dangerous condition (e.g., an increasingly excessive temperature is measured), the controller 520 may not only instruct the switching circuit to disconnect the entire battery pack circuit, but may also provide a communication signal to other BMSs instructing them to open their respective switching circuits, which may help contain the dangerous condition.

[0048] The controller 520 may utilize intelligent monitoring and control of the battery cells to maximize the battery's usable capacity, optimize charge and discharge rates, and minimize the number of battery charge cycles to extend the overall lifespan of the battery cells. Accordingly, the controller may utilize artificial intelligence at the cell level, such as machine learning and / or deep learning algorithms, when processing measurement data. For example, the controller 520 may use machine learning algorithms to predict whether a first battery cell is likely to experience a critical condition (e.g., thermal runaway) based on current and past measurement data of the local cell, other cells in the battery system, and pre-programmed information related to various critical conditions. Similar algorithms may also be utilized to provide more accurate SoC and SoH calculations using accurate real-time measurements of cell parameters, operating conditions, and changes in the battery cells as a result of charge or discharge cycles. Furthermore, machine learning algorithms may be used to accurately determine instantaneous output power calculations. This may be based, for example, on cell voltage, charge rate, temperature, charge direction (charge or discharge), and impedance (corresponding to both DC and AC).

[0049] As mentioned above, one advantage of the BMS system described herein is improved safety. The BMS system described herein may achieve this by implementing various protection mechanisms at the local level of each battery cell, such as overvoltage and undervoltage protection, overcurrent protection, and thermal management. In the event of a fault or abnormal condition, the BMS can trigger safety measures, including disconnecting the battery cell from the load or charging source to prevent potential hazards such as overheating or fire. This safety aspect is particularly important in applications where large battery packs are used, such as electric vehicles, stationary energy storage systems, and renewable energy installations. Furthermore, each local battery cell may be disconnected whenever it is not in use, such as when the connected system is in standby or off mode (e.g., an electric vehicle parked in a garage). Utilizing local switching circuitry, individual battery cells in a battery stack can be disconnected during safety-critical conditions or bypassed for safety. This local control may also help extend battery pack run time or battery pack lifespan, or may advantageously enable partial connection or shortening for cell balancing, regulation, and / or temperature balancing. In typical BMS designs, changing the battery stack configuration during BMS operation is either infeasible or adds undesirable complexity to the BMS design. However, in some of the aspects described herein, battery cells may be replaced in real time by simply locally bypassing the original battery cell being replaced.

[0050] FIG. 6A illustrates various connection types for the bidirectional communication interfaces of the battery management systems 610, 620, 630, 640, and 650. Specifically, FIG. 6A illustrates a wired daisy-chain connection of BCIs, with optional redundant paths shown between the first BMS 610 and the fifth BMS 650. FIG. 6B illustrates a wired parallel connection of BCIs. FIG. 6C illustrates a wireless connection of BCIs. Other possible connection types, or combinations of the types shown, may be used to enable communication between the various BMSs described herein. A BCI may be configured to seamlessly connect BMSs within a battery system, creating a bidirectional information network between all battery units (or modules). As described, when connected to another BCI within a battery system, the BCI may be configured to transfer battery cell information stored and / or generated within each BMS. Examples of battery cell information that can be communicated include, for example, cell voltage, cell current, cell capacity, cell temperature, stored cell history data, faults, embedded algorithms, timestamps, switching circuit control commands, and cell identification / authentication, which can be used to prevent unauthorized BMS access.

[0051] The cell-to-cell communication provided by the BCI associated with each BMS may be used as a redundant verification solution in battery stack design. Using the BCI, cell information, such as information obtained from the cell controllers of each BMS in the battery system, may be exchanged, shared, and verified by all BMSs in the battery system, thereby providing redundancy for cell parameter measurements, switching circuit status and control, computational data, faults, battery cell history data, SoC / SoH calculation data, system memory data, hysteresis behavior, and / or cell ID / authentication. In typical BMS designs, adding such redundant verification is difficult due to circuit complexity, cost, and size. By enabling all BMSs in the battery system to function as a verification solution, improvements in overall safety, reliability, and performance may be achieved.

[0052] While many examples in this disclosure have a single battery cell associated with each BMS, it should be understood that other arrangements are possible. For example, FIG. 7 illustrates various multi-cell configurations associated with three different BMS systems (represented by boxes). As shown, each BMS may simultaneously control multiple battery cells, which may be connected in series, parallel, or a combination thereof. In doing so, the BMS may effectively treat this combination of battery cells as a single collective battery cell. For example, switching circuitry and / or cell sensors may be collectively attributed to each multi-cell group (i.e., each individual cell cannot be bypassed, but the multi-cell group can be bypassed together). It should also be understood that other variations on the systems described herein may be possible. For example, selected components (e.g., system memory) may be included only in some BMSs or may be located external to the battery system, with the functionality of these selected components accessed through bidirectional communication between the various BMSs.

[0053] FIG. 8 illustrates a battery unit 800 configured to be incorporated into a battery system that may incorporate any of the teachings previously described herein regarding a BMS. As shown, the battery unit 800 may include a battery cell 811 enclosed within a housing 860. By combining with the housing 860, various components may form a BMS and be in electrical communication with the battery cell 811, including switching circuitry (a switch controller 810, a cell switch 812, and a bypass switch 814), a bidirectional communication interface 830, and a cell controller 820. The controller 820 may be connected to several sensors around the cell, including a voltage sensor 822, a temperature sensor 824, and multiple current sensors 826, 828. While shown as enclosed within the housing 860, alternative placements of the BMS are possible, including being attached to the exterior of the housing 860.

[0054] The housing 860 may be configured to provide electrical access between the battery cell 811 and at least one battery cell not contained within the housing 860. To facilitate this connection, the housing 860 may include electrical ports 816, 818 configured to provide electrical access between the battery cell 811 and any battery cells not contained within the housing 860. Similarly, the housing 860 may be configured to provide electrical access between the bidirectional communication interface 830 and other BMSs that may be connected to the battery unit 800. Consistent with the localized control of the battery cells described herein, the housing 860 may not specifically enclose additional battery cells configured to be connected with the battery cell 811. Similarly, the housing 860 may specifically enclose only a single composite cell, as described above in connection with FIG. 7 .

[0055] Advantageously, the distance separating the controller 820 and the battery cells 811 may be reduced by the proximity of the BMS to the battery cells 811. Specifically, the controller 820 or the BMS may be smaller than the maximum width of the battery cells 811, or more specifically, less than half the maximum width of the battery cells 811. The controller 820 may be integrated directly with the terminals of the battery cells 811, such that no wires are used to connect these two components. As mentioned above, integrating the BMS directly with the battery cells 811 within the battery unit 800 significantly reduces the length of the wiring connection between the BMS and the battery cells 811, thus producing more accurate measurements with minimal latency. Shorter latency may equate to substantially better fault response, improved SoC and SoH calculation accuracy, and parasitic impedance calculation. Thus, voltage drop and noise interference associated with long wires and error-prone connectors may be avoided using this integrated battery unit structure. Additionally, this flexible battery pack assembly architecture may allow for simple "building block" assembly of battery packs and also allows for individual cells within the battery pack to be serviceable, significantly reducing cost of ownership and extending battery life.

[0056] 9A-9C illustrate a battery system with a localized BMS having multiple battery cell chemistries (Li-Ion, Na-Ion, Li-S, LiFePO4) and their fully charged capacities. Because some aspects of the systems and methods described herein enable localized control of each battery cell, such multi-chemistry systems can be easily constructed, controlled, charged, and discharged. Given that various battery chemistries are particularly suited to specific discharge and charge applications, the ability to continue using a functional cell while bypassing other cells in the circuit can be highly advantageous. For example, FIG. 9B illustrates the battery system of FIG. 9A in its partially discharged state, with the Li-S battery still substantially unusable. As shown in the examples, different cell chemistries discharge at different rates at various float voltages. The single-cell BMS described herein accurately captures these differences and seamlessly generates the appropriate control to release sodium ions first (with the lowest energy density and capacity) up to their SoC limits. The BMS then continues to guide the battery to discharge the remaining cells in order of their energy density. Thus, if discharging continues in this example, the BMS associated with the Na-Ion cell may control its switching circuitry to bypass this cell after it has fully exhausted its operating range while the Li-S battery cell continues to discharge in the circuit. Similarly, FIG. 9C shows the battery system in a partially charged state. Once the Na-Ion cell is fully charged, the BMS may ensure that this cell is bypassed while the other cells complete their charge.

[0057] As described, the BMSs of each battery cell can be configured to communicate cell characteristic information (e.g., number of cells, capacity, chemistry type, etc.) with each other, so that each BMS can be configured to determine the overall structure and performance of the battery system, including the operating range and actual usable capacity of the entire battery system. Using this information, the controller can further self-configure and optimize the SOC and SOH. The BMSs can be configured to perform these calculations immediately upon pairing with a new BMS.

[0058] In addition, the BMS can handle different input charging voltages (e.g., 400V DC to 800V DC ), thereby enabling the battery system to adapt to different charging infrastructure types (i.e., 800V DC The battery system is 800V DC or 400V DC FIG. 10A shows the battery system fully charged from an 800V charger. As with discharging, complex SoC calculations and safe charge termination processes can be realized by the BMS and its integrated switching circuitry (i.e., power path switches). The BMS can detect the input voltage swing range during the initial handshake when the charger cable is connected. Once the input voltage swing is established, the BMS can calculate the battery stack voltage range (using bidirectional communication) to determine which cells to connect or bypass. As shown in this example, each of the four battery cells in this example is a 200V cell, so they may be charged simultaneously using an 800V charger. However, FIG. 10B shows the battery system of FIG. 10A connected to a 400V charger. In conventional systems, charging this battery pack from this charger is generally impractical without additional conversion equipment. However, the local bypass control described herein can also "virtually" realize changes in the battery system voltage, allowing batteries to be charged at different voltages. For example, as shown, half of the battery cells may be fully charged and the other half may be fully discharged and bypassed in the circuit, awaiting their turn to be charged. The same bypass technique may be used to control the output voltage discharged by the battery. For example, some of the battery cells included in a battery system may be controllably discharged while other battery cells are not, thereby allowing the system to provide different output voltages and provide active cell balancing during discharge.

[0059] It should be readily understood that the systems and methods described herein may be applied to numerous battery chemistry types, and indeed particularly allow for the combination of different battery chemistry types within the same pack. For example, a lithium-ion battery cell may be selected along with a second battery cell selected from the group consisting of, for example, a nickel-metal hydride battery cell, a lead-acid battery cell, and a sodium-ion battery cell. In particular, a battery system may include battery cells having different capacities from one another. As one possibility, the high energy density of a lithium-ion battery cell may be combined with the fast charging capability of a sodium-ion battery cell. Such chemistry and / or battery cell capacity mismatches are easily supported by the sole and independent control of each single-cell BMS.

[0060] The energy management system described herein is applicable to energy systems other than the described battery management system. For example, an energy storage system may include multiple energy storage cells (e.g., supercapacitors, fuel cells, etc.) and multiple energy storage management systems (ESMS) in electrical communication with each energy storage cell. Each ESMS may incorporate any of the teachings described herein regarding the example battery system BMS, including the use of local single-cell controllers and local switching circuits. In this manner, systems that combine the benefits of multiple different energy sources, such as by seamlessly integrating multiple battery cells with multiple supercapacitors, can be easily built. Similar to battery systems with different chemistries, the ESMS may be configured to communicate to accommodate the addition of various new types of energy sources and may include pre-programmed software for identifying and managing various energy source combinations.

[0061] FIG. 11 illustrates a method 1100 for controlling a battery system. At 1102, measurement data is obtained for a first battery cell in a battery having multiple battery cells connected via a battery pack circuit. Next, at 1104, a battery management system (BMS) is used to determine whether the first battery cell is experiencing a critical condition based on the first battery cell measurement data. Finally, at 1106, the first battery cell is disconnected in a manner that causes the battery pack circuit to bypass the first battery cell. In other words, method 1100 enables selective bypass of a single battery cell experiencing a critical condition (e.g., thermal runaway) based on measurement data (e.g., cell temperature readings). Beyond critical conditions, method 1100 can also be applied to defective battery conditions, such as when a battery cell is not functioning properly (e.g., not providing discharge).

[0062] 12 illustrates a method 1200 for charging a battery system. At 1202, information regarding the output voltage of a charger is received. At 1204, a battery management system (BMS) is used to determine whether the voltage range of a plurality of battery cells connected within a battery pack can be charged using the output voltage of the charger. Finally, at 1206, at least one of the plurality of battery cells is disconnected in a manner such that the battery pack circuit bypasses the at least one disconnected battery cell, reducing the voltage range of the connected battery cells within the circuit to a voltage chargeable by the charger. This method thus enables selective charging of only a portion of the total number of battery cells in the battery system, thereby expanding the variety of chargers that can charge the battery system.

[0063] FIG. 13 illustrates a method 1300 for manufacturing a battery system. At 1202, a first battery unit is electrically connected to a second battery unit. The first battery unit may include a first battery cell and a first battery management system (BMS) coupled to the first battery cell, and the second battery unit may similarly include a second battery cell and a second BMS coupled to the first battery cell. In this manner, multiple battery units, each with its own BMS, can be easily combined using this method. While conventional systems often require a BMS to be built to match the number and type of battery cells ultimately deployed in the system, method 1300 enables a “building block” assembly process in which each battery unit is simply connected together, limiting the need for further adjustments to the already-integrated BMS.

[0064] In accordance with the above description, in one aspect, the present disclosure provides a battery system. The battery system may include a first battery cell in a battery pack and a first battery management system (BMS) in communication with the first battery cell. The first BMS may include a first controller configured to receive measurement data of the first battery cell, process the first battery cell measurement data, and generate a control signal based on the processed first battery cell measurement data. The battery system may also include a second battery cell in the battery pack and a second BMS in communication with the second battery cell. The second BMS may include a second controller configured to receive measurement data of the second battery cell, process the second battery cell measurement data, and generate a control signal based on the processed second battery cell measurement data. The first controller may be configured to determine a charge rate and a state of health of the first battery cell when processing the first battery cell measurement data, and the second controller may be configured to determine a charge rate and a state of health of the second battery cell when processing the second battery cell measurement data. The first BMS may further include a first temperature sensor configured to measure a temperature of the first battery cell, and the first battery cell measurement data may include temperature data. Similarly, the second BMS may further include a second temperature sensor configured to measure a temperature of the second battery cell, and the second battery cell measurement data may include temperature data. The second controller may be configured to generate a control signal based on both the processed measurement data from the second battery cell and the temperature data measured by the temperature sensor of the first BMS.

[0065] The first BMS may further include a first voltage sensor configured to measure a voltage of the first battery cell, and the first battery cell measurement data may include voltage data. Similarly, the second BMS may further include a second voltage sensor configured to measure a voltage of the second battery cell, and the second battery cell measurement data may include voltage data. The first BMS may further include a first current sensor configured to measure a current of the first battery cell, and the first battery cell measurement data may include current data. Similarly, the second BMS may further include a second current sensor configured to measure a current of the second battery cell, and the second battery cell measurement data may include current data.

[0066] The first BMS may further include a switching circuit configured to disconnect the first battery cell from the battery pack. The switching circuit may be configured to receive a control signal based on the first battery cell measurement data and to disconnect the first battery cell from the battery pack. Furthermore, the first controller may be configured to process the measurement data of the first battery cell to determine whether the first battery cell is experiencing an unsafe condition and to generate the control signal only if the first battery cell is experiencing an unsafe condition. The switching circuit may include a cell switch configured to control an electrical connection between the first battery cell and the battery pack and a bypass switch configured to control an electrical connection on an electrical path of the battery pack that bypasses the first battery cell.

[0067] The first controller may include a first system memory configured to store first battery cell measurement data (including both processed and / or raw measurement data). Similarly, the second controller may include a second system memory configured to store second battery cell measurement data (including both processed and / or raw measurement data). The first system memory may store information regarding a temperature range and an operating voltage range of the first battery cell. The first controller may be configured to determine whether the temperature range or the operating voltage range of the first battery cell has been exceeded and generate a control signal to disconnect the first battery cell in a manner that causes the battery pack to bypass the first battery cell. The first BMS may include a first bidirectional communication interface in electrical communication with the first controller, and the second BMS may include a second bidirectional communication interface in electrical communication with the second controller. The first and second bidirectional communication interfaces may be configured to communicate information between the first controller and the second controller. The first bidirectional communication interface may be configured to communicate the processed first battery cell measurement data to the second bidirectional communication interface. Similarly, the second bidirectional communication interface may be configured to communicate the processed second battery cell measurement data to the first bidirectional communication interface. The first battery cell measurement data may include first battery cell voltage data, first battery cell current data, first battery cell capacity data, and / or first battery cell temperature data. The first bidirectional communication interface may be configured to communicate to the second bidirectional communication interface that the control signal was generated based on the processed first battery cell measurement data. The first bidirectional communication interface may be configured to communicate information regarding the battery chemistry type or cell capacity of the first battery cell to the second bidirectional communication interface. The control signals of the first and second controllers may also be based on information communicated between the first controller and the second controller.

[0068] The first controller and the second controller may be configured to operate autonomously without user intervention to generate the control signal. The first controller may be configured to process the first battery cell measurement data by applying a machine learning algorithm. The machine learning algorithm may be configured to determine whether the first battery cell is experiencing an unsafe condition. The first battery cell may have a different battery chemistry type or a different cell capacity than the second battery cell. The first battery cell may be a lithium-ion battery cell, while the second battery cell may be selected from the group consisting of nickel-metal hydride battery cells, lead-acid battery cells, and sodium-ion battery cells. The first battery cell may have a different cell capacity than the second battery cell.

[0069] The battery system may further include a third battery cell in the battery pack and a third BMS in communication with the third battery cell. The third BMS may include a third controller configured to receive measurement data of the third battery cell, process the third battery cell measurement data, and generate a control signal based on the processed measurement data of the third battery cell.

[0070] In another aspect, the present disclosure provides a battery system that may include a first battery management system (BMS) including a first switching circuit configured to control connectivity of a first battery cell in a battery pack. The battery system may include a second BMS including a second switching circuit configured to control connectivity of a second battery cell in the battery pack.

[0071] The first switching circuit may be further configured to connect, disconnect, bypass, and short-circuit the first battery cell. Similarly, the second switching circuit may be further configured to connect, disconnect, bypass, and short-circuit the second battery cell. The first switching circuit may include a cell switch configured to control an electrical connection between the first battery cell and the battery pack and a bypass switch configured to control an electrical connection on an electrical path of the battery pack that bypasses the first battery cell. The first BMS may be configured to control the switching circuit to actively balance the first battery cell. The first BMS may be configured to determine whether the battery pack is not in use and to disconnect the first battery cell if the battery pack is not in use. Similarly, the second BMS may be configured to determine whether the battery pack is not in use and to disconnect the second battery cell if the battery pack is not in use. The first BMS may be configured to determine whether the first battery cell is experiencing an unsafe condition. The first BMS may be configured to control the first switching circuit to disconnect the first battery cell if the first battery cell is experiencing an unsafe condition. The first BMS may be configured to control the first switching circuit to bypass the first battery cell. The first BMS may be configured to communicate to the second BMS that the first battery cell is experiencing an unsafe condition.

[0072] In another aspect, the present disclosure provides a battery unit. The battery unit may include battery cells and a housing enclosing the battery cells. The housing may be configured to provide electrical access between the battery cells and at least one battery cell not contained within the housing. The battery unit may also include a battery management system (BMS) coupled to the enclosure and in communication with the battery cells. The BMS may include a controller configured to receive battery cell measurement data, process the battery cell measurement data, and generate a control signal based on the processed battery cell measurement data.

[0073] The BMS may be included within the housing. The housing may not specifically enclose the additional battery cell configured to be connected with the battery cell. The housing may include at least one electrical port configured to provide electrical access between the battery cell and at least one battery cell not included within the housing. A distance separating the battery management system and the battery cell may be less than half the maximum width of the battery cell. The BMS may include a system memory configured to store measurement data of the first battery cell. The BMS may include a bidirectional communication interface configured to communicate information between the BMS and the additional BMS. The housing may be configured to provide electrical access between the bidirectional communication interface and the additional BMS. The housing may include at least one communication port configured to provide electrical access between the bidirectional communication interface and the additional BMS. The system memory may store information regarding the battery capacity, voltage, and battery chemistry of the battery cell, and the BMS may be configured to communicate this information to the additional BMS.

[0074] In one aspect, the present disclosure provides an energy storage system. The energy storage system may include a first energy storage cell and a first energy storage management system (ESMS) in communication with the first energy storage cell. The first ESMS may include a controller configured to receive measurement data for the first energy storage cell, process the measurement data for the first energy storage cell, and generate a control signal based on the processed measurement data for the first energy storage cell. The energy storage system may also include a second energy storage cell in communication with the first energy storage cell and a second ESMS in communication with the second energy storage cell. The second ESMS may include a controller configured to receive measurement data for the second energy storage cell, process the measurement data for the second energy storage cell, and generate a control signal based on the processed measurement data for the second energy storage cell. The first energy storage cell may be a capacitor, a supercapacitor, or a fuel cell. The second energy storage cell may be a battery cell. Alternatively, the second energy storage cell may be a capacitor, a supercapacitor, or a fuel cell.

[0075] In the description above and in the claims, phrases such as "at least one" or "one or more" may follow a list of elements or features. Also, the term "and / or" may be used in a list of two or more elements or features. Unless implicitly or explicitly contradicted by the context in which it is used, such phrases are intended to mean any of the listed elements or features individually, or any of the listed elements or features in combination with any of the other listed elements or features. For example, the phrases "at least one of A and B," "one or more of A and B," and "A and / or B" are intended to mean "A only, B only, or both A and B," respectively. A similar interpretation is also intended for lists containing more than two items. For example, the phrases "at least one of A, B, and C," "one or more of A, B, and C," and "A, B, and / or C" are intended to mean "A only, B only, C only, both A and B, both A and C, both B and C, or both A, B, and C," respectively. Additionally, use of the phrase "based on" above and in the claims is intended to mean "based at least in part on," allowing for unrecited features or elements.

[0076] The subject matter described herein may be embodied in systems, devices, methods, and / or articles, depending on the desired configuration. The embodiments set forth in the foregoing description do not represent all embodiments consistent with the subject matter described herein. Instead, they are merely some examples consistent with aspects related to the described subject matter. While several variations have been described in detail above, other modifications or additions are possible. In particular, additional features and / or variations may be provided in addition to those described herein. For example, the above-described embodiments may be directed to various combinations and subcombinations of the disclosed features and / or combinations and subcombinations of several additional features disclosed above. Other embodiments may be within the scope of the following claims.

Claims

1. a first battery cell in the battery pack; a first battery management system (BMS) in communication with the first battery cell, the first BMS including a first controller configured to receive measurement data for the first battery cell, process the measurement data of the first battery cell, and generate a control signal based on the processed measurement data from the first battery cell; a second battery cell in the battery pack; a second BMS in communication with the second battery cell, and a second BMS including a second controller configured to receive measurement data for the second battery cell, process the measurement data of the second battery cell, and generate a control signal based on the processed measurement data from the second battery cell.

2. the first controller is configured to determine a state of charge and a state of health of the first battery cell when processing the measurement data of the first battery cell; and The system of claim 1 , wherein the second controller is configured to determine a charge rate and a state of health of the second battery cell when processing the measurement data of the second battery cell.

3. 2. The system of claim 1, wherein the first BMS further includes a switching circuit configured to disconnect the first battery cell from the battery pack, the switching circuit configured to receive the control signal based on measurement data of the first battery cell and to disconnect the first battery cell from the battery pack for safety or performance reasons.

4. 2. The system of claim 1, wherein the first controller is configured to process measurement data of the first battery cell to determine whether the first battery cell is experiencing an unsafe condition, and to generate the control signal only if the first battery cell is experiencing an unsafe condition.

5. the first controller includes a first system memory configured to store measurement data of the first battery cell, the processed measurement data from the first battery cell, or the control signal provided by the first controller; and 2. The system of claim 1, wherein the second controller includes a second system memory configured to store measurement data of the second battery cell, the processed measurement data from the second battery cell, or the control signal provided by the second controller.

6. 2. The system of claim 1, wherein the first BMS includes a first bidirectional communication interface in electrical communication with the first controller, and the second BMS includes a second bidirectional communication interface in electrical communication with the second controller, the first and second bidirectional communication interfaces configured to communicate information between the first controller and the second controller.

7. The system of claim 6 , wherein the control signals of the first controller and the second controller are also based on the information communicated between the first controller and the second controller.

8. The first BMS further includes a first temperature sensor configured to measure a temperature of the first battery cell, and the measurement data of the first battery cell includes temperature data; 8. The system of claim 7, wherein the second controller is configured to generate the control signal based on both the processed measurement data from the second battery cell and the temperature data measured by the temperature sensor of the first BMS.

9. 10. The system of claim 1, wherein the first battery cell has a different battery chemistry type or a different cell capacity than the second battery cell.

10. The system of claim 1 , wherein the first controller and the second controller are configured to operate autonomously without user intervention to generate the control signals.

11. a first battery management system (BMS) including a first switching circuit configured to control connectivity of a first battery cell in the battery pack; A battery system including a second BMS including a second switching circuit configured to control connectivity of a second battery cell in the battery pack.

12. the first switching circuit is further configured to connect, disconnect, bypass, and short-circuit the first battery cell; 12. The battery system of claim 11, wherein the second switching circuit is further configured to connect, disconnect, bypass, and short the second battery cell.

13. The first switching circuit a cell switch configured to control the electrical connection between the first battery cell and the battery pack; a bypass switch configured to control the electrical connection on an electrical path of the battery pack that bypasses the first battery cell.

14. the first BMS is configured to determine whether the battery pack is not in use, and to disconnect the first battery cell if the battery pack is not in use; 12. The battery system of claim 11, wherein the second BMS is configured to determine whether the battery pack is not in use and to disconnect the second battery cells if the battery pack is not in use.

15. the first BMS is configured to determine whether the first battery cell is experiencing a critical condition; 12. The battery system of claim 11, wherein the first BMS is configured to control the first switching circuit to disconnect or bypass the first battery cell when the first battery cell is experiencing a critical condition.

16. A battery cell; a housing enclosing the battery cells, the housing configured to provide electrical access between the battery cells and at least one battery cell not contained within the housing; a battery management system (BMS) coupled to the enclosure and in communication with the battery cells, the first BMS comprising: the BMS including a controller configured to receive measurement data for the battery cells, process the measurement data for the battery cells, and generate control signals based on the processed measurement data from the battery cells.

17. The battery unit of claim 16 , wherein the BMS is contained within the housing.

18. 18. The battery unit of claim 17, wherein the housing does not enclose additional battery cells configured to be connected with the battery cells.

19. 17. The battery unit of claim 16, wherein the housing includes at least one electrical port configured to provide electrical access between the battery cells and at least one battery cell not contained within the housing.

20. the BMS includes a bidirectional communication interface configured to communicate information between the BMS and an additional BMS; The battery unit of claim 16 , wherein the housing includes at least one communication port configured to provide electrical access between the bidirectional communication interface and the additional BMS.

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