Distributed battery management system for electric vehicles

Abstract

The present disclosure relates to a distributed battery management system for electric vehicles. A distributed battery management system for a multi-module traction battery pack of an electric vehicle is provided. The battery management system includes an analog-to-digital converter (ADC) integrated into a battery module of a traction battery pack of an electric vehicle, and a master controller external to the battery module and in digital data communication with the ADC. The ADC converts an analog signal indicative of a sensed voltage associated with one or more cells of the battery module into a digital signal indicative of the sensed voltage. The master controller performs a function associated with the traction battery pack of the electric vehicle based on the sensed voltage.

Description

[0001] Cross-citation and priority claims of related applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 135,452, filed January 8, 2021, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure generally relates to electric vehicles, and more specifically to battery management systems for electric vehicles. Background Technology

[0004] Electric vehicles may include a battery pack with multiple battery modules, each connected to a central battery management system (BMS). The BMS receives sensed parameters from the battery modules and uses these parameters as input to control the operation of the battery pack. For example, the BMS is responsible for ensuring the batteries operate within their safe operating conditions, monitoring the battery's state of charge (SoC) and state of health (SoH), balancing the operation of the battery cells within each module, and other functions. Reliable sensed parameters from the battery modules are essential for the BMS to facilitate safe and efficient control of the battery pack. Summary of the Invention

[0005] In one aspect, this disclosure describes a battery module comprising:

[0006] Multiple battery cells; and

[0007] An integrated battery module controller includes an analog-to-digital converter and at least one connector for connecting to tabs of multiple battery cells, wherein the distance between the analog-to-digital converter and the at least one connector is between 20-100 mm.

[0008] The integrated battery module controller communicates with the main battery management controller, which is located far from the battery module.

[0009] The battery module may also include a group of battery cell tabs, the group including battery cell tabs for at least two of the plurality of battery cells, wherein at least one connector is connected to the group of battery cell tabs.

[0010] The distance between the analog-to-digital converter and at least one connector can be between 35 and 60 mm.

[0011] The distance between the analog-to-digital converter and at least one connector can be between 40-50 mm.

[0012] Multiple battery cells may include more than four battery cells.

[0013] The plurality of battery cells can include 12 battery cells.

[0014] The at least one connector can include 7 connectors. A distance between the analog-to-digital converter and each of the 7 connectors can be between 20-100 mm.

[0015] The battery module can include a thermistor. A distance between the analog-to-digital converter and the thermistor can be less than 100 mm.

[0016] The plurality of battery cells can be a plurality of battery soft-pack cells.

[0017] The integrated battery module controller can be coupled to a surface of the battery module.

[0018] Embodiments can include combinations of the above features.

[0019] In another aspect, the disclosure describes an electric vehicle, comprising:

[0020] two battery modules each including a plurality of battery cells;

[0021] a modular distributed battery management system, comprising:

[0022] a central battery management controller remote from the two battery modules; and

[0023] two integrated battery module controllers each coupled to a respective one of the two battery modules;

[0024] wherein each integrated battery module controller includes an analog-to-digital converter and at least one connector for connecting to a tab of a battery cell of its respective plurality of battery cells; and

[0025] wherein a distance between the analog-to-digital converter and the at least one connector is between 20-100 mm.

[0026] The two integrated battery module controllers can be daisy-chained together.

[0027] In some embodiments, each battery module can include a prismatic housing housing its respective plurality of battery cells.

[0028] The battery modules can be arranged in a stacked manner.

[0029] Embodiments can include combinations of the above features.

[0030] In another aspect, the disclosure describes a distributed battery management system for a multi-module traction battery pack of an electric vehicle. The distributed battery management system includes:

[0031] an analog-to-digital converter (ADC) integrated into a battery module of a traction battery pack of an electric vehicle, the ADC converting an analog signal indicative of a sensed voltage associated with one or more cells of the battery module into a digital signal indicative of the sensed voltage; and

[0032] a main controller performing functions associated with the traction battery pack of the electric vehicle based on the sensed voltage, the main controller being external to the battery module and in digital data communication with the ADC to receive the digital signal indicative of the sensed voltage from the ADC.

[0033] The battery module can be a first battery module. The ADC can be part of a first module controller integrated into the first battery module. The distributed battery management system can include a second module controller integrated into a second battery module of the traction battery pack of the electric vehicle. The first module controller and the second module controller can be connected together in a daisy chain fashion.

[0034] The main controller can be in digital data communication with both the first module controller and the second module controller via a controller area network (CAN) bus.

[0035] The distributed battery management system can include a printed circuit board having the ADC mounted thereon. The printed circuit board can define an electrical conductor establishing electrical communication from the ADC to a voltage sensing location associated with the one or more cells of the battery module. A length of the electrical conductor can be less than or equal to 100 mm.

[0036] The one or more cells of the battery module can include a plurality of cells of the battery module. The ADC can be electrically connected to a plurality of voltage sensing locations associated with the plurality of cells of the battery module. The ADC can convert a plurality of analog signals indicative of respective sensed voltages at the plurality of voltage sensing locations into a digital signal indicative of the respective sensed voltages.

[0037] Embodiments can include combinations of the above features.

[0038] In another aspect, the present disclosure describes a powersport vehicle including a distributed battery management system as disclosed herein.

[0039] In another aspect, the present disclosure describes a field replaceable battery module of a multi-module traction battery pack of an electric vehicle. The field replaceable battery module includes:

[0040] one or more battery cells;

[0041] a module controller converting an analog signal indicative of a sensed voltage associated with the one or more battery cells of the field replaceable battery module into a digital signal indicative of the sensed voltage; and

[0042] a digital communication interface to communicate a digital signal indicative of the sensed voltage outside the field replaceable battery module.

[0043] The field replaceable battery module can include a cover that covers a tab associated with one or more battery cells. The cover can also cover the module controller.

[0044] The field replaceable battery module can include a printed circuit board on which the module controller is mounted. The printed circuit board can define a conductive body that establishes electrical communication from the module controller to a voltage sensing location associated with one or more cells of the battery module. A length of the conductive body can be less than or equal to 100 mm.

[0045] The one or more battery cells can include six or more battery cells.

[0046] The field replaceable battery module can include a printed circuit board on which the module controller is mounted. The printed circuit board can define a conductive body that establishes electrical communication from the module controller to a voltage sensing location associated with six or more cells of the field replaceable battery module. A length of each conductive body can be less than or equal to 100 mm.

[0047] Embodiments can include combinations of the above features.

[0048] In another aspect, the disclosure describes a method of performing a function associated with operation of a traction battery pack of an electric vehicle. The method includes:

[0049] at the battery module: generating an analog signal indicative of a sensed voltage associated with one or more battery cells; and converting the analog signal to a digital signal indicative of the sensed voltage;

[0050] communicating the digital signal indicative of the sensed voltage to a main controller outside the battery module; and

[0051] performing, using the main controller, a function associated with operation of the traction battery pack based on the sensed voltage.

[0052] The method can include converting the analog signal to the digital signal at a distance of less than or equal to 100 mm from a voltage sensing location used to generate the analog signal.

[0053] The analog signal can be a first analog signal indicative of a first sensed voltage associated with a first battery cell of the one or more battery cells. The digital signal can be a first digital signal indicative of the first sensed voltage. The method can include, at the battery module:

[0054] generating a second analog signal indicative of a second sensed voltage associated with a second battery cell of the one or more battery cells;

[0055] At a first distance of less than or equal to 100 mm from the first voltage sensing position used to generate the first analog signal, the first analog signal is converted into a first digital signal; and

[0056] At a second distance of less than or equal to 100 mm from the second voltage sensing position used to generate the second analog signal, the second analog signal is converted into a second digital signal indicating the second sensing voltage.

[0057] The method may include:

[0058] The second digital signal indicating the second sensing voltage is transmitted to the main controller; and

[0059] The main controller is used to perform functions associated with the operation of the traction battery pack based on the first and second sensed voltages.

[0060] Implementation examples may include combinations of the features described above.

[0061] Further details regarding these and other aspects of the subject matter of this application will become apparent from the detailed description and accompanying drawings included below. Attached Figure Description

[0062] Now refer to the attached diagram, in which:

[0063] Figure 1 This is a schematic diagram of an exemplary electric vehicle that includes a battery management system as described herein;

[0064] Figure 2 yes Figure 1 An exemplary schematic diagram of a vehicle's battery management system;

[0065] Figure 3 yes Figure 1 A schematic diagram of an exemplary topology of the battery modules in a vehicle's battery pack;

[0066] Figure 4 yes Figure 1 A perspective view of an exemplary multi-battery module of a vehicle's battery pack;

[0067] Figure 5 Its cover was removed. Figure 4 A perspective view of a portion of a multi-cell battery module;

[0068] Figure 6 The cover was removed. Figure 4 A top view of a multi-cell battery module;

[0069] Figure 7 yes Figure 4 A schematic top view of a multi-cell battery module;

[0070] Figure 8is a perspective view of an exemplary battery pack including Figure 4

[0071] Figure 9 is a flowchart of a method of monitoring voltages of battery cells of a battery module of an electric vehicle. DETAILED DESCRIPTION

[0072] The following disclosure describes battery management systems (BMS) and related components and methods for electric vehicles. In some embodiments, the systems and methods described herein can be particularly suitable for use with electric sport vehicles. Suitable electric sport vehicles include snowmobiles, motorcycles, watercraft such as boats and personal watercraft (PWC), all-terrain vehicles (ATVs), and utility task vehicles (UTVs) (e.g., side-by-side). In some embodiments, the systems and methods described herein can facilitate control and operation of a traction battery pack by promoting high reliability and accuracy of sensed parameters (e.g., voltage(s) and temperature(s)) associated with batteries of battery modules of the traction battery pack. In some embodiments, the systems and methods described herein can facilitate a reduction in wiring between a master battery management controller and battery modules of a traction battery pack.

[0073] In electric vehicles implementing a centralized BMS, where each battery module of a battery pack is associated with a small module controller on a printed circuit board (PCB) located remotely from the battery module, the module controller takes analog readings of voltage and temperature of one or more battery cells within the battery module. Each battery module can be connected to the small controller via a number of wires, resulting in a relatively large number of wires that travel a relatively long distance from each battery module to its respective module controller at the central battery management controller. Failure of any portion of the central battery management controller PCB (e.g., a module controller or a connector) can require replacement and reconnection of the entire PCB. Additionally, replacement of a battery module can require re-wiring of the battery module to the central battery management controller. Furthermore, transmitting analog signals over longer conductors can increase the risk of signal loss (e.g., voltage drop) and / or signal noise affecting the accuracy of the analog signals.

[0074] ​In contrast to a centralized BMS, a distributed BMS as described herein can include a module controller associated with each battery module and integrated and in digital data communication with a master battery management controller that controls operation of the battery pack based on one or more sensed parameters (e.g., voltage, temperature) communicated in digital form from the module controller(s) to the master battery management controller. In some embodiments, a single module controller can be configured to perform analog-to-digital conversion of one or more parameters associated with the battery cells of its battery module. A suitable data bus can be used to communicate the sensed parameters from one or from multiple module controllers to the master battery management controller. Accordingly, in some embodiments, the architecture of the distributed BMS described herein can facilitate reduced cost, reduced wiring, reduced number of parts, and / or reduced complexity. In some embodiments, the distributed BMS can improve modularity of the battery pack, as battery modules can be more easily connected to and disconnected from the distributed BMS in comparison to a centralized BMS. Moreover, the proximity of the module controller to the tab or other (e.g., voltage, temperature) sensing location of the battery cell can also improve the accuracy and reliability of the sensed voltage and / or other sensed parameters. This, in turn, can facilitate efficient control of the battery pack by reducing the risk of signal loss and / or signal noise that can otherwise be associated with passing analog signals through longer conductive bodies.

[0075] The terms "connected" and "coupled" can include direct connection and coupling (in which two elements that are in physical contact with each other) and indirect connection and coupling (in which at least one additional element is located between two elements). The term "connected" also includes electrical connection.

[0076] The term "substantially" as used herein can apply to any quantitative representation that can occur a tolerable variation without resulting in a change in the basic function to which it is related.

[0077] Aspects of various embodiments are described with reference to the drawings.

[0078] Figure 1 is a schematic illustration of an exemplary electrically motorized vehicle 10 (hereinafter referred to as "vehicle 10") that includes a battery management system 12 (hereinafter referred to as "BMS 12") as described herein. As Figure 1As shown, the vehicle 10 can be a snowmobile, but it should be understood that the systems described herein can also be used in other types of electric vehicles, such as UTVs, electric ATVs, electric PWCs, electric motorcycles, boats with electric outboard motors, and other electric sport vehicles. In some embodiments, the vehicle 10 can be an electric snowmobile, including elements of the snow vehicles described in International Patent Publication No. WO 2019 / 049109 Al (entitled: BATTERY ARRANGEMENT FOR ELECTRIC SNOW VEHICLES) and U.S. Patent Application No. 63 / 135,497 (entitled: ELECTRIC VEHICLE WITH BATTERY PACK AS STRUCTURAL ELEMENT), which are incorporated herein by reference.

[0079] The vehicle 10 can include a frame (also referred to as a chassis), which can include a tunnel 14, tracks 16 in the form of annular belts for engaging the ground and disposed (i.e., located) beneath the tunnel 14, one or more electric motors 18 (referred to in the singular below) mounted on the frame and configured to drive the tracks 16, skis 20 disposed at the front of the vehicle 10, left and right, a step 22 disposed above the tunnel 14 for accommodating an operator of the vehicle 10, and optionally one or more passengers (not shown). The skis 20 can be movably attached to the frame to allow the vehicle 10 to be steered via a steering assembly including a steering column interconnecting handlebars 24 with the skis 20.

[0080] The electric motor 18 can be drivingly coupled to the track 16 via a drive shaft. The electric motor 18 can be in torque-transferring engagement with the drive shaft via a belt / pulley drive. However, the electric motor 18 can be in torque-transferring engagement with the drive shaft via other arrangements, such as a chain / sprocket drive or a shaft / gear drive, for example. The drive shaft can be drivingly coupled to the track 16 via one or more cogged wheels or other devices so as to transfer power from the electric motor 18 to the track 16.

[0081] In various embodiments, the electric motor 18 can be, for example, a permanent magnet synchronous motor or a brushless direct current motor. In some embodiments, for example, the electric motor 18 can have a rated output power between 120 and 180 horsepower, or the electric motor 18 can have a maximum rated output power greater than 180 horsepower. The electric motor 18 can be the same type of electric motor described in U.S. Provisional Patent Application Serial No. US 63 / 135,466 (title: DRIVE UNIT FOR ELECTRIC VEHICLE) and U.S. Provisional Patent Application Serial No. US 63 / 135,474 (title: DRIVE UNIT WITH FLUID PATHWAYS FOR ELECTRIC VEHICLE), both of which are incorporated herein by reference, or can include elements of these electric motors. In some embodiments, multiple electric motors can be implemented to drive the vehicle 10.

[0082] The vehicle 10 can also include one or more brakes, which can be applied or released by an operator by actuating a suitable brake actuator (e.g., a joystick), for example. In various embodiments, the brake(s) can include a friction-type brake that includes a master cylinder hydraulically connected to brake calipers that press brake pads against a brake rotor or brake disc coupled to a powertrain of the vehicle 10. Actuation of the brake actuator (e.g., joystick) can cause a combination of friction braking and regenerative braking. Regenerative braking can also be applied alone, i.e., without friction braking. In some embodiments, regenerative braking can be used such that the battery pack(s) 26 (referred to in the singular below) of the vehicle 10 are provided with electrical energy generated by the electric motor 18 operating as a generator when the brake actuator is applied and / or the operator releases the accelerator 28.

[0083] When the vehicle 10 is propelled by the electric motor 18, the battery pack 26 can provide electrical power to the electric motor 18 to drive the electric motor 18. The battery pack 26 can be a main battery pack for propelling the vehicle 10. In other words, the battery pack 26 can also be referred to as a “power” or “traction” battery pack. The battery pack 26 can be located below the seat 22. In some embodiments, the battery pack 26 can be a rechargeable multi-module, multi-cell lithium-ion battery pack, as explained further below. For example, the battery cells of the battery pack 26 can be soft-pack cells, cylindrical cells, and / or prismatic cells. The battery pack 26 can include a battery enclosure to house the battery modules and / or battery cells to protect against impact, water, and / or debris. In some embodiments, for example, the battery pack 26 can be configured to output electrical power at a voltage between 300-400 volts or up to 800 volts, for example.

[0084] The operation of the electric motor 18 and the power delivery from the battery pack 26 to the electric motor 18 can be controlled by one or more vehicle controllers 30 based on operator actuation of the accelerator 28 (also referred to as the "throttle"). The power delivery to the electric motor 18 can be controlled via suitable power electronic modules, such as power inverters (not shown), including electronic switches (e.g., one or more insulated-gate bipolar transistors), to provide the electric motor 18 with desired voltage, current, waveform, etc., to achieve the desired performance of the vehicle 10. In some embodiments, one or more vehicle controllers 30 may include one or more electronic control units (ECUs) or one or more electronic control modules (ECMs). An example of an ECU or ECM is a motor controller that may or may include a power inverter. One or more vehicle controllers 30 may include a computer comprising one or more data processors and a non-transitory machine-readable memory storing instructions executed by the one or more data processors. One or more vehicle controllers 30 may control various aspects of the vehicle 10 based on sensed inputs and / or operator inputs.

[0085] One or more vehicle controllers 30 may include a main battery management controller 32 (hereinafter referred to as "main controller 32"), which may be part of BMS 12. Main controller 32 may be integrated with the control system of vehicle 10, such as... Figure 2 As shown, the main controller 32 is part of one or more vehicle controllers 30. Alternatively, the main controller 32 may be part of a separate BMS 12, independent of the control system of the vehicle 10. The vehicle controllers 30 may operate one or more other systems 42 of the vehicle 10 (such as...). Figure 2 (as shown) and communicate with one or more other systems. For example, vehicle controller 30 can communicate with, for example, the steering system, electric motor 18, power management and thermal management of vehicle 10, and optionally perform control functions associated with, for example, the steering system, electric motor 18, power management and thermal management of vehicle 10.

[0086] The main controller 32 can include a computer comprising one or more data processors and non-transitory machine-readable memory storing instructions for execution by the one or more data processors. The main controller 32 can also or instead include an application-specific integrated circuit (ASIC) and / or a field-programmable gate array (FPGA). Through the use of the main controller 32 and one or more module controllers described below, the BMS 12 can perform various monitoring and control functions associated with the operation of the battery pack 26. The BMS 12 can include any suitable electronic system that manages the battery pack 26 or portion(s) thereof. Examples of functions performed by the BMS 12 can include protecting the battery pack 26 from operating outside of its safe operating area (e.g., overcurrent protection and monitoring the state of the battery pack 26), calculating and reporting data associated with the battery pack 26 (e.g., voltage, state of charge), controlling the environment in which the battery pack 26 operates, verifying the battery pack 26 and / or balancing the battery pack 26. The BMS 12 can monitor the state of the battery pack 26 as represented by parameters such as, for example, the total voltage of the battery pack 26, the voltage of individual cells or groups of cells, the average temperature, the cooling liquid inlet temperature, the cooling liquid outlet temperature, the temperature of individual cells, the cooling liquid flow in embodiments in which the battery pack 26 is liquid-cooled or air-cooled, and / or the current flowing into or out of the battery pack 26. The BMS 12 can control the current flow by controlling / actuating one or more switches and / or the cooling liquid flow by controlling / actuating one or more valves, performing one or more control functions associated with the battery pack 26. In some embodiments, the BMS 12 can control a heater (not shown) to heat the battery pack 26 when the battery pack 26 is below a defined operating temperature. The heater can be implemented within a thermal management system to heat the cooling liquid.

[0087] Figure 2 is a schematic diagram of an exemplary distributed BMS 12 of the vehicle 10. The BMS 12 can include battery module controllers 34A-34N (collectively referred to herein as “module controllers 34”), each associated with and integrated with a respective battery module 36A-36N (collectively referred to herein as “battery modules 36”) of the battery pack 26. The battery modules 36 can be located within a common battery pack 26. The battery pack 26 can be operatively connected to power the electric motor 18 and, optionally, one or more other electrical loads within the vehicle 10. The battery pack 26 can include two or more battery modules 36. In some embodiments, the battery pack 26 can include fourteen or more battery modules 36. In some embodiments, the battery pack 26 can include sixteen battery modules 36. In some embodiments, the battery modules 36 can be electrically daisy-chained in series for delivering power to the electric motor 18 and, optionally, other electrical loads of the vehicle 10.

[0088] In some embodiments, each module controller 34 can be operable to obtain a sensed parameter, such as a voltage and temperature reading associated with one or more battery cells within its associated battery module 36. Each module controller 34 can be operatively connected to one or more sensors 38A-38N (e.g., thermistor(s) for voltage sensing, thermocouple(s), conductors, connectors, and connections) to obtain one or more sensed parameters. In embodiments where a battery module 36 includes more than one temperature sensor, readings from the multiple temperature sensors can be averaged at the module controller 34, and the average temperature associated with the applicable battery module 36 can be communicated to the main controller 32. Voltage readings can be obtained, for example, through a conductor extending from the module controller 34 to a tab of the battery module 36 or to other voltage sensing locations as explained below.

[0089] Each integrated module controller 34 can be in digital data communication with the main controller 32 via a wireless or wired connection. In some embodiments, the module controllers 34 can each be in digital data communication with the main controller 32 via a data bus 40. In various embodiments, the data bus 40 can be a controller area network (CAN) bus, or a suitable serial peripheral interface such as, for example, the isoSPI bus available from Analog Devices, Inc. of Norwood, Massachusetts under the trade designation ADUM TM Coupling circuits are known. The module controllers 34 can act as intermediaries that feed digital data indicative of sensed parameters to the main controller 32. The module controllers 34 can also receive instructions from the main controller 32 and, for example, cause discharge of individual battery cells when instructed by the main controller 32. In some embodiments, the module controllers 34 can not perform control logic for controlling operation of their respective battery modules 36. The module controllers 34 can each have built-in analog-to-digital converter (ADC) capability. Alternatively, the battery modules 36 can each have an ADC that is external to the module controller 34 and in data communication with the module controller 34. The module controllers 34 can each include or be a microcontroller, such as a CAN controller, that can store data bits received from the data bus 40 and also serially transfer the bits onto the data bus 40 when the data bus 40 is idle.

[0090] The main controller 32 can be integrated with the battery pack 26 or can be placed externally to the battery pack 26. The main controller 32 can perform control and / or monitoring functions of the BMS 12. For example, the main controller 32 can aggregate data received from the module controllers 34 as digital signals and perform logic to control one or more operations associated with the battery pack 26, such as directing charging of the battery cells, directing discharging of the battery cells, and / or directing other functions associated with the battery pack 26. For example, temperature readings of cells or groups of cells can be used to control a cooling system that delivers a coolant to the battery modules 36.

[0091] The BMS 12 can have a distributed architecture, where some (e.g., data acquisition and analog-to-digital conversion) functions can be performed locally at individual battery modules 36 using module controllers 34, and other (e.g., battery management and control) functions can be performed remotely from individual battery modules 36 using the master controller 32. The BMS 12 and the battery pack 26 can each have a modular construction.

[0092] Figure 3 is a schematic diagram of an exemplary topology of a battery module 36 of the battery pack 26 of the vehicle 10. Various embodiments of the battery module 36 can include one or more battery cells 44A-44L (collectively referred to herein as “cells 44”). In some embodiments, the battery module 36 can include two or more cells 44. In some embodiments, the battery module 36 can include six or more cells 44. In some embodiments, the battery module 36 can include twelve or more cells 44.

[0093] In Figure 3 embodiments, the battery module 36 includes six pairs of cells 44 connected in series (i.e., daisy-chained together) (i.e., a first pair includes cells 44A and 44B, a second pair includes cells 44C and 44D, a third pair includes cells 44E and 44F, a fourth pair includes cells 44G and 44H, a fifth pair includes cells 441 and 44J, and a sixth pair includes cells 44K and 44L). The two cells 44 in each pair of cells 44 are connected in parallel. In other embodiments, the battery module 36 can have other topologies. For example, the battery module 36 can include 12 cells 44 in total, outputting twice the current and six times the voltage of a single cell 44.

[0094] The battery module 36 can include conductors 46A-46G (collectively referred to herein as “conductors 46”) extending between the module controller 34 and suitable parameter sensing locations 48A-48G (collectively referred to herein as “sensing locations 48”) for measuring voltage and / or temperature associated with the cells 44. The conductors 46A-46F can function as parameter sensing wires. In embodiments where the sensing locations 48 are voltage sensing locations, the conductors 46 can each include a (e.g., copper) wire and / or a track / traces on a printed circuit board. The sensing locations 48 can include tabs (i.e., positive and negative connections) of individual cells 44 or groups of cells 44. Alternatively, the sensing locations 48 can include intermediate connectors in electrical communication with the tabs of the cells 44 or groups of cells 44 of the battery module 36 to allow for voltage sensing. The groups of tabs of the cells 44 can be configured to correspond to a lowest voltage point of the battery module 36 (e.g., sensing location 48A), a highest voltage point of the battery module 36 (e.g., sensing location 48G), and every point between pairs of cells 44 connected in series for a total of seven sensing locations 48 (e.g., sensing locations 48G-48F).

[0095] The conductors 46 can establish electrical communication between the module controller 34 and the sensing locations 48 via a soldered connection, a riveted connection, a welded connection, a crimped connection, a connector, or other suitable electrical connection. The conductors 46A and 46B can be used to measure voltage across the electrically parallel pair of cells 44A and 44B. Similarly, the conductors 46B and 46C can be used to measure voltage across the electrically parallel pair of cells 44C and 44D. The conductors 46 can be used to measure voltage across other pairs of electrically parallel cells 44 in a similar manner.

[0096] In some embodiments, the distance D between the module controller 34 and the sensing locations 48 can be relatively short to facilitate a short length of the individual conductors 46. The short length of the conductors 46 can in turn promote measurement accuracy by reducing signal loss and reducing noise risk. In some embodiments, the lengths of the individual conductors 46 can be substantially the same and within a desired tolerance that provides similar signal loss between the conductors 46. In some embodiments, the lengths of the individual conductors 46 can be different but still within a predetermined range that provides an acceptable level of signal loss or noise risk. In other words, the lengths of the conductors 46 can not be uniform across all of the conductors 46. The length of the conductors 46 can be a factor that affects signal loss (e.g., conductor impedance). Other factors that can affect signal loss can include, for example, the material type and cross-sectional area of the conductors 46.

[0097] Distance D can represent a physical (e.g., two-dimensional or three-dimensional) straight-line distance between module controller 34 and a respective sensing location 48. Distance D can also represent a path length of conductive body(ies) 46 that establish electrical communication between module controller 34 and respective sensing location 48. In various embodiments, distance D can be less than or equal to 100 mm for any, one, some, or all of sensing locations 48. For example, 100 mm can represent a threshold below which signal loss and / or noise associated with conductive body(ies) 46 is within an acceptable range to provide reliable and accurate measurements. In some embodiments, distance D can be between 20 mm and 100 mm for any, one, some, or all of sensing locations 48. In some embodiments, distance D can be between 35 mm and 60 mm for any, one, some, or all of sensing locations 48. In some embodiments, distance D can be between 40 mm and 50 mm for any, one, some, or all of sensing locations 48. Reducing the range of values for distance D can reduce variations in signal loss and noise associated with different sensing locations 48. Referring to Figure 3 In some embodiments, seven conductive bodies 46 can each have a length less than or equal to 100 mm. In some embodiments, seven sensing locations 48 can each be located at a straight-line distance less than or equal to 100 mm from module controller 34.

[0098] Battery module 36 can include one or more connectors 50A, 50B that connect module controller 34 to data bus 40. In some embodiments, one or more connectors 50A, 50B can be located on a printed circuit board (PCB) that is separate from module controller 34. In some embodiments, one or more connectors 50A, 50B can be located on a PCB that is part of module controller 34. Figure 3In some embodiments, the digital signals communicated on the data bus 40 can be more resilient to noise and loss than analog signals. Thus, the battery modules 36 can be spaced apart from the main controller 32 while still communicating accurate and reliable sensor data. This can allow the battery modules 36 to be positioned within the vehicle 10 without the limitations imposed by signal loss and / or noise. Space and weight are at a premium in electric vehicles, particularly electrically powered vehicles. Being able to distribute the size and weight associated with the battery modules 36 within the vehicle 10 without the limitations imposed by signal loss and / or noise can provide design improvements. For example, the battery modules 36 can be positioned within the vehicle 10 to improve space efficiency and / or to achieve an improved center of mass. Further, the daisy chain configuration of the data bus 40 can enable multiple smaller battery modules 36 (e.g., more than four battery modules 36) to be implemented without increasing the number of lines connected to the main controller 32. Smaller battery modules 36 can be more easily placed within the available space in the vehicle 10 to achieve a smaller overall profile of the vehicle 10.

[0099] In some embodiments, the digital signals communicated on the data bus 40 can be more resilient to noise and loss than analog signals. Thus, the battery modules 36 can be spaced apart from the main controller 32 while still communicating accurate and reliable sensor data. This can allow the battery modules 36 to be positioned within the vehicle 10 without the limitations imposed by signal loss and / or noise. Space and weight are at a premium in electric vehicles, particularly electrically powered vehicles. Being able to distribute the size and weight associated with the battery modules 36 within the vehicle 10 without the limitations imposed by signal loss and / or noise can provide design improvements. For example, the battery modules 36 can be positioned within the vehicle 10 to improve space efficiency and / or to achieve an improved center of mass. Further, the daisy chain configuration of the data bus 40 can enable multiple smaller battery modules 36 (e.g., more than four battery modules 36) to be implemented without increasing the number of lines connected to the main controller 32. Smaller battery modules 36 can be more easily placed within the available space in the vehicle 10 to achieve a smaller overall profile of the vehicle 10.

[0100] Figure 4is a perspective view of an exemplary multi-cell battery module 36 of a battery pack 26 of a vehicle 10. In some embodiments, the battery cells 44 can be battery cells contained in a prismatic (e.g., rectangular) housing or casing. The prismatic housing can enable the battery module 36 to be stacked or otherwise arranged in a space-efficient manner. In some embodiments, the cells 44 can be soft-pack battery cells. In some embodiments, the cells 44 can be lithium-ion battery cells, although it should be understood that aspects of the present disclosure are applicable to other types of battery cells as well. In some embodiments, the battery module 36 can have a cooling panel integrated therein for fluid communication with a source of cooling fluid. For example, the battery module 36 can have a cooling panel and cells 44 as disclosed in U.S. Patent Publication No. 2021 / 0135307 Al (Title: BATTERY COOLING PANEL FOR ELECTRIC VEHICLES), which is incorporated herein by reference.

[0101] The battery module 36 can include a positive terminal 52A and a negative terminal 52B, which can be used to electrically connect the battery module 36 to other battery modules 36 and / or to electrical loads of the vehicle 10. The battery module 36 can include a removable cover 54 that defines a portion of the housing of the battery module 36. The cover 54 can cover the module controller 34 and, optionally, other components of the battery module 36. The connectors 50A, 50B can be accessible via one or more apertures formed in the cover 54.

[0102] The battery module 36 can be configured as a modular, field-replaceable unit or component that is designed to be relatively easy and quick to replace as a unit to restore the operational condition of the battery pack 26. For example, in the event of a failure of the battery module 36, such as a failure of one or more cells 44 or a failure of the module controller 34, the failed battery module 36 can be relatively easily replaced through the use of the connectors 50A, 50B as described above, without the need to replace other, functionally normal battery modules 36 or other components of the battery pack 26 or BMS 12.

[0103] Figure 5 is a perspective view of the battery module 36 of Figure 4 is a perspective view of the upper portion of the battery module 36. Removal of the removable cover 54 can expose the module controller 34 and the tab 58. The module controller 34 can be placed on a PCB 56 that can be integrated in the battery module 36 by being secured to a structural component (e.g., housing, sleeve, frame) of the battery module 36.

[0104] Figure 6 is a perspective view of the battery module 36 of Figure 4 is a top view of the battery module 36 ofFigure 6 A plan view of a front face 57 of the battery module 36 is shown. Figure 6 A module controller 34 connected to the data bus 40 in a daisy chain fashion via connectors 50A, 50B is shown schematically. In some embodiments, the module controller 34 can be configured to be connected in parallel via the connectors 50A, 50B instead. The module controller 34 can be located on (e.g., a front or other) face 57 of the battery module 36 and coupled to the face 57. For example, the module controller 34 can be physically implemented as one or more chips and / or other electronic devices on a PCB 56 that is mounted (e.g., attached, secured, and / or soldered) to the same side of the battery module 36 as the tabs 58 (sheets) associated with the cells 44 of the battery module 36. The module controller 34 can be implemented as a microcontroller with a built-in ADC 51. Alternatively, the ADC 51 can be implemented separately from the module controller 34. The module controller 34 and / or the ADC 51 can be located toward the middle (i.e., center region) of the PCB 56 and also in a relative center of the sensing locations 48.

[0105] Referring to Figure 6 , the sensing locations 48A-48D can correspond to voltage sensing locations, and the sensing location 48T can correspond to a temperature sensing location. For example, the sensing location 48T can be a location of a thermistor electrically connected to the module controller 34 via the electrically conductive body(ies) 46T. The thermistor can be arranged between the battery cells 44 of the battery module 36. As shown, the distance Dl is a straight-line distance between the sensing location 48T and the module controller 34. The distance D2 is a straight-line distance between the sensing location 48B and the module controller 34. The distances Dl, D2 can alternatively represent respective lengths of the electrically conductive bodies 46T, 46B. In some embodiments, Figure 6 The distances Dl and D2 shown in FIG. 1 can be less than or equal to 100 mm. In some embodiments, the distances Dl and D2 can be between 35 mm and 60 mm. In some embodiments, the distances Dl and D2 can be between 40 mm and 50 mm. In some embodiments, the module controller 34 can communicate with four or more cells 44 via the electrically conductive bodies 46. In some embodiments, the module controller 34 can communicate with six to twelve cells 44 via the electrically conductive bodies 46.

[0106] As Figure 6As shown, some of the sense locations 48 can correspond to locations of intermediate connectors that are in electrical communication with the tabs 58 of a single cell 44 and / or with groups of tabs 58 of cells 44 of the battery module 36. Each grouping of tabs 58 can include a combination of tabs 58 from more than one cell 44. The battery module 36 can include any number of groupings of tabs 58, and the ADC 51 of the module controller 34 can be in communication with any number of groupings of tabs 58.

[0107] To attach the module controller 34, which can have previously been integrated with the PCB 56, to the face 57 of the battery module 36, the groupings of tabs 58 can first be electrically connected together via one or more metal strips, referred to as“V-sense” connectors, which can be soldered or welded to the applicable tabs 58 to provide suitable sense locations 48. The sense locations 48 can correspond to electrical connectors that provide electrical communication between the conductors 46 and the tabs 58. Such electrical connectors can be soldered to the V-sense connectors to physically attach the PCB 56 containing the module controller 34 to the battery module 36. The module controller 34 with integrated ADC 51 can be electrically connected to the plurality of tabs 58 in this manner. The battery module 36 can include seven groupings of tabs 58, and from this, the module controller 34 can be in electrical communication with the tabs 58 via seven electrical connections at different sense locations 48. For example, referring to FIG. 1, Figure 3 The grouping of tabs 58 corresponding to sense location 48A can include tabs from battery cells 44A, 44B, the grouping of tabs 58 corresponding to sense location 48B can include tabs from battery cells 44A, 44B, 44C, 44D, etc. For clarity, Figure 6 Only four voltage sense locations 48A-48D are identified in FIG. 1. In some embodiments, there can be one soldered connection per V-sense connector and electrical connector combination at the sense locations 48. In some embodiments, it can be desirable to have two or more soldered connections per V-sense connector and electrical connector combination at the sense locations 48 to improve reliability.

[0108] When connecting the module controller 34 to the battery module 36 without damaging the circuitry of the PCB 56, the negative terminal 52B of the battery module 36 can be grounded first. This can be done by connecting a conductive element 60 (e.g., a wire, solder, or other suitable conductor) between the negative terminal 52B (e.g., the lower left grouping of the tabs 58) and the ground G. The ground G can be a bolt on the positive face 57 of the battery module 36, among other possibilities. Once the negative terminal 52B is grounded, electrical connections can be made at the sense locations 48, for example, by soldering electrical connectors to the V sense connectors, and soldering the V sense connectors to the appropriate tabs 58. Alternatively, to avoid connecting the negative terminal 52B to the ground G prior to installation of the module controller 34, one or more mechanical fuse (e.g., jack) connectors 62 can be installed on the PCB 56. In this way, when ready, there will be no electrical connection between the tabs 58 and the circuitry of the PCB 56 prior to adding mechanical fuses to the PCB 56 via the mechanical fuse connectors 62.

[0109] Figure 7 is Figure 4 a schematic top view of a multi-cell battery module 36 showing seven voltage sense locations 48A-48H configured in a similar manner as shown in Figure 3 , although the conductive bodies 46 are shown as straight lines in Figure 7 . Note that one or more of the conductive bodies 46 can instead include bends or curves. Figure 7 shows a plan view of the positive face 57 of the battery module 36. Figure 7 One temperature sense location 48T is also shown, although the battery module 36 can include multiple temperature sense locations that can correspond to multiple temperature sensors arranged at different locations within the battery module 36. The sense locations 48 can be arranged at different distances (e.g., D3 and D4) from the ADC 51, where such distances can be less than or equal to 100 mm, as explained above. The module controller 34 can be installed to the PCB 56 and the conductive bodies 46 can each include tracks / traces on the PCB 56. In some embodiments, the sense locations 48 can be defined on the PCB 56. Thus, the distance between the ADC 51 and the sense locations 48 can be within the bounds of the PCB 56 integrated into the battery module 36.

[0110] The ADC 51 can convert the analog signals indicative of the sensed voltages at the sense locations 48 and associated with one or more cells 44 to digital signals indicative of the sensed voltages. The module controller 34 can then remotely communicate the digital signals to the host controller 32 via the data bus 40.

[0111] As Figure 7As shown, the ADC 51 can be substantially centered on the face 57 of the battery module 36 and / or substantially centered on the plurality of sense locations 48. In some embodiments, the ADC 51 is substantially centered on the PCB 56.

[0112] Figure 8 is a perspective view of an example battery pack 26 including a plurality of multi-cell battery modules 36 with their covers 54 removed. Figure 4 The battery modules 36 can be arranged in a plurality of stacks. In some embodiments, the battery pack 26 can include eight battery modules 36 linked together in a daisy chain along the data bus 40. The master controller 32 can be arranged external (i.e., remote) to the battery pack 26 and still in digital data communication with the individual battery modules 36 via the data bus 40. The battery modules 36 can also be electrically daisy chained together via bus bars 64 that electrically connect the positive and negative terminals 52A, 52B of adjacent battery modules 36 together to electrically connect the battery modules 36 in series.

[0113] Figure 9 is a flowchart of a method 100 of performing functions associated with operation of a traction battery pack of an electric vehicle. The method 100 can be performed using the BMS 12 or another BMS. Aspects of the method 100 can be combined with other actions described herein. Aspects of the BMS 12 and vehicle described herein can be incorporated into the method 100. In various embodiments, the method 100 can include:

[0114] at the battery module 36: generating an analog signal indicative of a sensed voltage associated with one or more battery cells 44 (block 102); and converting the analog signal to a digital signal indicative of the sensed voltage (block 104);

[0115] communicating the digital signal indicative of the sensed voltage to a master controller 32 external to the battery module 36 (block 106); and

[0116] performing, using the master controller 32, a function associated with operation of the traction battery pack 26 based on the sensed voltage (block 108).

[0117] In some embodiments, the method 100 can include converting the analog signal to the digital signal at a distance of less than or equal to 100 mm from the voltage sense location 48 used to generate the analog signal.

[0118] In some embodiments of the method 100, the analog signal can be a first analog signal indicative of a first sensed voltage associated with a first battery cell of the one or more battery cells 44. The digital signal can be a first digital signal indicative of the first sensed voltage. The method 100 can include, at the battery module 36, generating a second analog signal indicative of a second sensed voltage associated with a second battery cell of the one or more battery cells 44. The method 100 can include, at the battery module 36, converting the first analog signal to the first digital signal at a first distance from a first voltage sensing location 48A used to generate the first analog signal that is less than or equal to 100 mm. The method 100 can include, at the battery module 36, converting the second analog signal to a second digital signal indicative of the second sensed voltage at a second distance from a second voltage sensing location 48B used to generate the second analog signal that is less than or equal to 100 mm.

[0119] In some embodiments, the method 100 can include communicating the second digital signal indicative of the second sensed voltage to the host controller 32. In some embodiments, the method 100 can include using the host controller 32 to perform a function associated with operation of the traction battery pack 26 based on the first sensed voltage and the second sensed voltage.

[0120] The embodiments described in this document provide non-limiting examples of possible implementations of the present technology. Those of ordinary skill in the art, having the benefit of the present disclosure, will appreciate that changes can be made to the embodiments described herein without departing from the scope of the present technology.

Claims

1. An electric vehicle comprising: two battery modules each comprising a plurality of battery cells; a modular distributed battery management system comprising: a central battery management controller located remotely from the two battery modules; and two integrated battery module controllers connected together in a daisy chain configuration via a data bus, each integrated battery module controller integrated into a printed circuit board (PCB) coupled to a respective surface of one of the two battery modules comprising tab leads of the plurality of battery cells of the one of the two battery modules; wherein: each integrated battery module controller comprises an analog-to-digital converter (ADC) within the PCB and at least one connector for connecting to the tab leads of the plurality of battery cells of its respective battery module; the at least one connector is configured to generate an analog signal indicative of a sensed voltage associated with at least one of the plurality of battery cells of its respective battery module; the ADC is configured to convert the analog signal to a digital signal indicative of the sensed voltage; a distance between the ADC and the at least one connector is between 20-100 mm; and the central battery management controller is in digital data communication with each ADC of the two integrated battery module controllers via the data bus to receive each digital signal.

2. The electric vehicle of claim 1, wherein each battery module comprises a prismatic housing housing its respective plurality of battery cells.

3. The electric vehicle of claim 2, wherein the battery modules are arranged in a stacked manner.

4. The electric vehicle of claim 1, wherein the distance between the ADC and the at least one connector of each integrated battery module controller is between 35-60 mm.

5. The electric vehicle of claim 1, wherein the distance between the ADC and the at least one connector of each integrated battery module controller is between 40-50 mm.

6. The electric vehicle of claim 1, wherein the plurality of battery cells of each battery module comprises greater than 4 battery cells.

7. The electric vehicle of claim 1, wherein the plurality of battery cells of each battery module comprises 12 battery cells.

8. The electric vehicle of claim 7, wherein the at least one connector of each battery module comprises 7 connectors, each of the 7 connectors having a distance between the ADC of an integrated battery module controller that is between 20-100 mm.

9. The electric vehicle of claim 1, wherein: each battery module comprises a thermistor; and a distance between each thermistor and the ADC of a respective integrated battery module controller is less than 100 mm.

10. The electric vehicle of claim 1, wherein the plurality of battery cells of each battery module are a plurality of battery pouch cells.

11. The electric vehicle of claim 1, wherein, for each integrated battery module controller: the at least one connector is configured to generate a plurality of analog signals indicative of sensed voltages associated with the plurality of battery cells of its respective battery module; and the ADC is configured to convert the plurality of analog signals to a plurality of digital signals indicative of the sensed voltages.

11. The electric vehicle of claim 1, wherein the central battery management controller is configured to determine a state of health of each battery module based on the plurality of digital signals.

12. The electric vehicle of claim 1, wherein the central battery management controller is configured to determine a state of charge of each battery module based on the plurality of digital signals.

13. The electric vehicle of claim 1, wherein the central battery management controller is configured to determine a state of power of each battery module based on the plurality of digital signals.

14. The electric vehicle of claim 1, wherein the central battery management controller is configured to determine a state of function of each battery module based on the plurality of digital signals.

15. The electric vehicle of claim 1, wherein the central battery management controller is configured to determine a state of health of each battery module based on the plurality of digital signals, to determine a state of charge of each battery module based on the plurality of digital signals, to determine a state of power of each battery module based on the plurality of digital signals, and to determine a state of function of each battery module based on the plurality of digital signals. The ADC is configured to convert the plurality of analog signals to digital signals indicative of a sensed voltage.

12. The electric vehicle of claim 1, wherein the data bus comprises a controller area network (CAN) bus.

13. The electric vehicle of claim 1, the printed circuit board defining a conductive body that establishes electrical communication from the ADC to the at least one connector connected to a voltage sensing location associated with the at least one cell of a respective battery module, the conductive body having a length less than or equal to 100 mm.

14. A distributed battery management system for a multi-module traction battery pack of an electric vehicle, the distributed battery management system comprising: a first module controller including a first analog-to-digital converter (ADC) integrated into a first printed circuit board (PCB) mounted to a same side of a first battery module of the traction battery pack as a first tab associated with one or more cells of the first battery module, the first ADC converting analog signals indicative of a first sensed voltage associated with the one or more cells of the first battery module to first digital signals indicative of the first sensed voltage; a second module controller including a second ADC integrated into a second PCB mounted to a same side of a second battery module of the traction battery pack as a second tab associated with one or more cells of the second battery module, the second ADC converting analog signals indicative of a second sensed voltage associated with the one or more cells of the second battery module to second digital signals indicative of the second sensed voltage, wherein the first and second module controllers are connected together in a daisy chain configuration via a data bus; and a master controller performing functions associated with the traction battery pack of the electric vehicle based on the first and second sensed voltages, the master controller being external to the first and second battery modules and in digital data communication with the first and second ADCs via the data bus to receive the first digital signals indicative of the first sensed voltage from the first ADC and the second digital signals indicative of the second sensed voltage from the second ADC.

15. The distributed battery management system of claim 14, wherein the data bus comprises a controller area network (CAN) bus.

16. The distributed battery management system of claim 14, wherein the first printed circuit board (PCB) defines an electrical conductor that establishes electrical communication from the first analog-to-digital converter (ADC) to a voltage sense location associated with the one or more cells of the first battery module, a length of the electrical conductor being less than or equal to 100 mm.

17. The distributed battery management system of claim 16, wherein the first printed circuit board (PCB) includes at least one connector in electrical communication with the electrical conductor, the connector being welded to a first tab of the one or more cells of the first battery module.

18. The distributed battery management system of claim 14, wherein: the one or more cells of the first battery module includes a plurality of cells of the first battery module; the first analog-to-digital converter (ADC) is electrically connected to a plurality of voltage sense locations associated with the plurality of cells of the first battery module; and the first analog-to-digital converter (ADC) converts a plurality of analog signals indicative of respective sensed voltages at the plurality of voltage sense locations to digital signals indicative of the respective sensed voltages.

19. The distributed battery management system of claim 14, wherein: the first printed circuit board (PCB) is soldered to a metal strip welded to the first tab of the one or more cells of the first battery module; and the second printed circuit board (PCB) is soldered to a metal strip welded to the second tab of the one or more cells of the second battery module.

20. An electrically powered motor vehicle comprising the distributed battery management system of claim 14. ​

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