Description:TECHNICAL FIELD
[0001] The present disclosure generally relates to improper connections detection system for a battery pack. In particular, the present disclosure discloses a system and a method for detecting improper connections in battery cells of a battery pack.

BACKGROUND
[0002] Generally, battery packs consist of multiple battery cells arranged in a series-parallel configuration, employing various methods such as wire bonding, busbars, spot welding, laser welding, ultrasonic welding, and Printed Circuit Board Assembly (PCBA) to connect the battery cells. However, these mechanical connections are susceptible to failure during production, transportation, or operation. If the cell becomes disconnected due to such issues, current flowing through the battery pack will redistribute among fewer cells, potentially leading to overcharging or over-discharging. This imbalance results in increased heat generation within the battery pack, accelerating its degradation and significantly reducing a life of a battery. Moreover, it can cause inaccuracies in estimating the battery pack's usable energy and instantaneous power, leading to premature shutdowns. Further, a disconnected cell bank will charge or discharge faster than the healthy ones, creating a substantial imbalance in the battery pack and limiting its maximum capacity utilization.
[0003] Additionally, a cell tab cut refers to separation of a tab connecting a positive cap of the battery cell to its internal components, typically caused by overcurrent conditions. This tab may be usually made of a material with a low melting point and is designed to handle currents up to a certain C-rate without overheating. However, when subjected to currents higher than its rating, the tab can heat up and melt due to the heat generated by the current passing through it. As a result, the cell becomes non-functional, even though its internal components, such as the jelly roll, remain intact. This failure typically occurs within a few seconds of an overcurrent event and may not immediately cause a noticeable increase in the temperature of a cell casing, as the jelly roll inside remains unaffected. Despite the tab being severed, the two halves of the tab may remain in contact for a short period, allowing some current to continue flowing through the cell, maintaining its voltage output.
[0004] However, because the contact area between the severed tab halves is small, its resistance increases significantly. This results in an immediate rise in the cell's Direct Current (DC) internal resistance (DCIR), which in turn leads to a shift in the cell's terminal voltage values. This increased resistance also imposes greater electrical stress on other cells connected in parallel, forcing more current to flow through them to compensate for the loss of the affected cell.
[0005] Further, a Circuit Interrupt Device (CID) in a lithium-ion cell is a mechanical safety feature activated within the cell itself. When gas pressure builds up inside the cell, the CID is triggered, causing it to open and release the gases through vents. This event disconnects the positive tab from the internal components (jelly roll), since the CID connects the positive tab to the positive cap of the cell. CID activation is a reversible process, and once the internal pressure decreases, the CID returns to its original position, restoring the cell's connection. As the CID activation is prompted by pressure buildup, the cell's temperature tends to rise during this event. This typically occurs during scenarios such as overcharging or thermal runaway. When the CID activates, the terminal voltage of the individual cell drops to zero. Furthermore, this event increases an electrical stress on other cells connected in parallel, leading to an increased current flow through them.
[0006] There is, therefore, a need for an improved system and method to detect improper connections in the battery cells of the battery pack by overcoming the deficiencies in the prior art(s).

OBJECTS OF THE PRESENT DISCLOSURE
[0007] A general object of the present disclosure is to provide a system and a method for detecting improper internal and external connections in battery cells of a battery pack during charge and discharge conditions of the battery pack in a more efficient manner.
[0008] An object of the present disclosure is to provide a system and a method that use cell voltage, temperature, and battery current measurements to determine improper connections of the battery cells.
[0009] An object of the present disclosure is to provide a system and a method that accurately and instantaneously estimate battery pack degradation and performance degradation due to increased electrical stress on certain cells in a battery pack caused by improper cell connections in the packs.
[0010] Another object of the present disclosure is to provide a system and a method that provide detailed information about safety risk faults triggered in a battery pack to help designers better understand safety issues in order to design the battery pack accordingly.

SUMMARY
[0011] Aspects of the present disclosure relate to improper connections detection system for a battery pack. In particular, the present disclosure discloses a system and a method for detecting improper connections in battery cells of a battery pack.
[0012] In an aspect, the present disclosure describes a method for detecting improper connections in battery cells of a battery pack. The method includes measuring, by a microcontroller associated with a system, voltage of each of a plurality of battery cells associated with the battery pack configured with the system. The method includes determining, by the microcontroller, a maximum voltage imbalance among the plurality of battery cells based on the measurement. The method includes measuring, by the microcontroller, a rate of change of the maximum voltage imbalance within a predefined time period. The method includes detecting, by the microcontroller, that a magnitude value of the rate of change of the maximum voltage imbalance is greater than a predefined threshold. Further, the method includes detecting, by the microcontroller, the improper connections in one or more battery cells of the plurality of battery cells based on the magnitude value, and updating one or more parameters of the battery pack based on the detection of the improper connections.
[0013] In an embodiment, measuring, by the microcontroller, the voltage of each of the plurality of battery cells may include detecting that a constant current is flowing through the battery pack from an external power source, and measuring the voltage of each of the plurality of battery cells associated with a plurality of cell blocks based on the detection of the flow of the constant current.
[0014] In an embodiment, determining, by the microcontroller, the maximum voltage imbalance among the plurality of battery cells based on the measurement may include detecting a maximum voltage and a minimum voltage of each cell block, and determining a difference between the maximum voltage and the minimum voltage of each cell block to determine the maximum voltage imbalance among the plurality of battery cells.
[0015] In an embodiment, updating, by the microcontroller, the one or more parameters based on the improper connections may include determining, by the microcontroller, that the rate of change of the voltage imbalance is greater than a minimum threshold, and determining, by the microcontroller, whether the rate of change of the voltage imbalance is greater than a maximum threshold. In response to a determination that the rate of change of the voltage imbalance is greater than the maximum threshold, the method may include determining, by the microcontroller, whether a temperature value of each of the plurality of battery cells is greater than a maximum limit. In response to a determination that the rate of change of the voltage imbalance is less than the maximum threshold, the method may include updating, by the microcontroller, the one or more parameters with a number of active battery cells in each cell block to measure a value of the one or more parameters for each cell block.
[0016] In an embodiment, updating, by the microcontroller, the one or more parameters with the number of active battery cells in each cell block to measure the value of the one or more parameters for each cell block may include detecting an improper internal connection in the one or more battery cells, determining a number of battery cells with the improper internal connection with respect to the magnitude value of the rate of change of the maximum voltage imbalance, and segregating the number of active battery cells in each cell block based on the number of battery cells with the improper internal connection to update the one or more parameters.
[0017] In an embodiment, in response to a determination that the temperature value is greater than the maximum limit, the method may include detecting, by the microcontroller, that a cell Circuit Interrupt Device (CID) is activated in the battery pack to facilitate to shut down the battery pack. In response to a determination that the temperature value is less than the maximum limit, the method may include updating, by the microcontroller, the one or more parameters with the number of active battery cells in each cell block to measure the value of the one or more parameters for each cell block.
[0018] In an embodiment, updating, by the microcontroller, the one or more parameters with the number of active battery cells in each cell block to measure the value of the one or more parameters for each cell block may include detecting, by the microcontroller, an improper external connection between the one or more battery cells, determining the number of battery cells with the improper external connection with respect to the magnitude value of the rate of change of the maximum voltage imbalance, and segregating the number of active battery cells in each cell block based on the number of battery cells with the improper external connection to update the one or more parameters.
[0019] In an embodiment, the one or more parameters may be at least one of a State of Charge (SoC), a State of Health (SoH), and battery pack protection techniques.
[0020] In an aspect, the present disclosure describes a system for detecting improper connections in battery cells of a battery pack. The system includes a microcontroller configured to measure voltage of each of a plurality of battery cells associated with the battery pack configured with the system. The microcontroller is configured to determine a maximum voltage imbalance among the plurality of battery cells based on the measurement. The microcontroller is configured to measure a rate of change of the maximum voltage imbalance within a predefined time period. The microcontroller is configured to detect that a magnitude value of the rate of change of the maximum voltage imbalance is greater than a predefined threshold. The microcontroller is configured to detect the improper connections in one or more battery cells of the plurality of battery cells based on the magnitude value, and update one or more parameters of the battery pack based on the detection of the improper connections.
[0021] In an embodiment, each of the plurality of battery cells may be associated with a plurality of cell blocks, and each of the plurality of cell blocks may be connected with each other in one of parallel configuration or series configuration.
[0022] In an embodiment, the microcontroller may be configured to detect a maximum voltage and a minimum voltage of each cell block, and determine a difference between the maximum voltage and the minimum voltage of each cell block to determine the maximum voltage imbalance among the plurality of battery cells.
[0023] In an embodiment, the microcontroller may be configured to determine that the rate of change of the voltage imbalance is greater than a minimum threshold, and determine whether the rate of change of the voltage imbalance is greater than a maximum threshold. In response to a determination that the rate of change of the voltage imbalance is greater than the maximum threshold, the microcontroller may be configured to determine whether a temperature value of each of the plurality of battery cells is greater than a maximum limit. In response to a determination that the rate of change of the voltage imbalance is less than the maximum threshold, the microcontroller may be configured to update the one or more parameters with a number of active battery cells in each cell block to measure a value of the one or more parameters for each cell block.
[0024] In an embodiment, the microcontroller may be configured to detect an improper internal connection in the one or more battery cells, determine a number of battery cells with the improper internal connection with respect to the magnitude value of the rate of change of the maximum voltage imbalance, and segregate the number of active battery cells in each cell block based on the determination of the number of battery cells with the improper internal connection to update the one or more parameters.
[0025] In an embodiment, in response to a determination that the temperature value is greater than the maximum limit, the microcontroller may be configured to detect that a cell CID is activated in the battery pack to facilitate to shut down the battery pack. In response to a determination that the temperature value is less than the maximum limit, the microcontroller may be configured to update the one or more parameters with the number of active battery cells in each cell block to measure the value of the one or more parameters for each cell block.
[0026] In an embodiment, the microcontroller may be configured to detect an improper external connection between the one or more battery cells, determine the number of battery cells with the improper external connection with respect to the magnitude value of the rate of change of the maximum voltage imbalance, and segregate the number of active battery cells in each cell block based on the determination of the number of battery cells with the improper external connection to update the one or more parameters.
[0027] Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.
[0029] FIG. 1 illustrates an example schematic view of an electric vehicle.
[0030] FIG. 2 illustrates an example flow chart for implementing a method for detecting improper connections in battery cells of a battery pack, according to embodiments of the present disclosure.
[0031] FIG. 3 illustrates an exemplary schematic view of a system associated with a battery pack for detecting improper connections in battery cells of the battery pack, according to embodiments of the present disclosure.

DETAILED DESCRIPTION
[0032] For the purpose of promoting an understanding of the principles of the present disclosure, reference will now be made to the various embodiments and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the present disclosure is thereby intended, such alterations and further modifications in the illustrated system, and such further applications of the principles of the present disclosure as illustrated therein being contemplated as would normally occur to one skilled in the art to which the present disclosure relates.
[0033] It will be understood by those skilled in the art that the foregoing general description and the following detailed description are explanatory of the present disclosure and are not intended to be restrictive thereof.
[0034] Whether or not a certain feature or element was limited to being used only once, it may still be referred to as “one or more features” or “one or more elements” or “at least one feature” or “at least one element.” Furthermore, the use of the terms “one or more” or “at least one” feature or element do not preclude there being none of that feature or element, unless otherwise specified by limiting language including, but not limited to, “there needs to be one or more…” or “one or more elements is required.
[0035] Reference is made herein to some “embodiments.” It should be understood that an embodiment is an example of a possible implementation of any features and/or elements of the present disclosure. Some embodiments have been described for the purpose of explaining one or more of the potential ways in which the specific features and/or elements of the proposed disclosure fulfil the requirements of uniqueness, utility, and non-obviousness.
[0036] Use of the phrases and/or terms including, but not limited to, “a first embodiment,” “a further embodiment,” “an alternate embodiment,” “one embodiment,” “an embodiment,” “multiple embodiments,” “some embodiments,” “other embodiments,” “further embodiment”, “furthermore embodiment”, “additional embodiment” or other variants thereof do not necessarily refer to the same embodiments. Unless otherwise specified, one or more particular features and/or elements described in connection with one or more embodiments may be found in one embodiment, or may be found in more than one embodiment, or may be found in all embodiments, or may be found in no embodiments. Although one or more features and/or elements may be described herein in the context of only a single embodiment, or in the context of more than one embodiment, or in the context of all embodiments, the features and/or elements may instead be provided separately or in any appropriate combination or not at all. Conversely, any features and/or elements described in the context of separate embodiments may alternatively be realized as existing together in the context of a single embodiment.
[0037] Any particular and all details set forth herein are used in the context of some embodiments and therefore should not necessarily be taken as limiting factors to the proposed disclosure. The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process or method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such process or method. Similarly, one or more devices or sub-systems or elements or structures or components proceeded by “comprises... a” does not, without more constraints, preclude the existence of other devices or other sub-systems or other elements or other structures or other components or additional devices or additional sub-systems or additional elements or additional structures or additional components.
[0038] Embodiments of the present disclosure will be described below in detail with reference to the accompanying drawings.
[0039] For the sake of clarity, the first digit of a reference numeral of each component of the present disclosure is indicative of the Figure number, in which the corresponding component is shown. For example, reference numerals starting with digit “1” are shown at least in FIG. 1. Similarly, reference numerals starting with digit “2” are shown at least in FIG. 2.
[0040] An Electric Vehicle (EV) or a battery powered vehicle including, and not limited to two-wheelers such as scooters, mopeds, motorbikes/motorcycles; three-wheelers such as auto-rickshaws, four-wheelers such as cars and other Light Commercial Vehicles (LCVs) and Heavy Commercial Vehicles (HCVs) primarily work on the principle of driving an electric motor using the power from the batteries provided in the EV. Furthermore, the electric vehicle may have at least one wheel which is electrically powered to traverse such a vehicle. The term ‘wheel’ may be referred to any ground-engaging member which allows traversal of the electric vehicle over a path. The types of EVs include Battery Electric Vehicle (BEV), Hybrid Electric Vehicle (HEV) and Range Extended Electric Vehicle. However, the subsequent paragraphs pertain to the different elements of a Battery Electric Vehicle (BEV).
[0041] In construction, as shown in FIG. 1, an EV (10) typically comprises a battery or battery pack (12) enclosed within a battery casing and includes a Battery Management System (BMS), an on-board charger (14), a Motor Controller Unit (MCU), an electric motor (16), and an electric transmission system (18). The primary function of the above-mentioned elements is detailed in the subsequent paragraphs: The battery of an EV (10) (also known as Electric Vehicle Battery (EVB) or traction battery) is re-chargeable in nature and is the primary source of energy required for the operation of the EV, wherein the battery (12) is typically charged using the electric current taken from the grid through a charging infrastructure (20). The battery may be charged using Alternating Current (AC) or Direct Current (DC), wherein in case of AC input, the on-board charger (14) converts the AC signal to DC signal after which the DC signal is transmitted to the battery via the BMS. However, in case of DC charging, the on-board charger (14) is bypassed, and the current is transmitted directly to the battery (12) via the BMS.
[0042] The battery (12) is made up of a plurality of cells which are grouped into a plurality of modules in a manner in which the temperature difference between the cells does not exceed a certain threshold. The terms “battery”, “cell”, and “battery cell” may be used interchangeably and may refer to any of a variety of different rechargeable cell compositions and configurations including, but not limited to, lithium-ion (e.g., lithium iron phosphate, lithium cobalt oxide, other lithium metal oxides, etc.), lithium-ion polymer, nickel metal hydride, nickel cadmium, nickel hydrogen, nickel-zinc, silver zinc, or other battery type/configuration. The term “battery pack” as used herein may be referred to multiple individual batteries enclosed within a single structure or multi-piece structure. The individual batteries may be electrically interconnected to achieve a desired voltage and capacity for a desired application. The Battery Management System (BMS) is an electronic system whose primary function is to ensure that the battery (12) is operating safely and efficiently. The BMS continuously monitors different parameters of the battery such as temperature, voltage, current, and so on, and communicates these parameters to the Electronic Control Unit (ECU) and the Motor Controller Unit (MCU) in the EV using a plurality of protocols including and not limited to Controller Area Network (CAN) bus protocol which facilitates the communication between the ECU/MCU and other peripheral elements of the EV (10) without the requirement of a host computer.
[0043] The MCU primarily controls/regulates the operation of the electric motor based on the signal transmitted from the vehicle battery, wherein the primary functions of the MCU include starting of the electric motor (16), stopping the electric motor (16), controlling the speed of the electric motor (16), enabling the vehicle to move in the reverse direction and protect the electric motor (16) from premature wear and tear. The primary function of the electric motor (16) is to convert electrical energy into mechanical energy, wherein the converted mechanical energy is subsequently transferred to the transmission system of the EV to facilitate movement of the EV. Additionally, the electric motor (16) also acts as a generator during regenerative braking (i.e., kinetic energy generated during vehicle braking/deceleration is converted into potential energy and stored in the battery of the EV). The types of motors generally employed in EVs include, but are not limited to DC series motor, Brushless DC motor (also known as BLDC motors), Permanent Magnet Synchronous Motor (PMSM), Three Phase AC Induction Motors and Switched Reluctance Motors (SRM).
[0044] The transmission system (18) of the EV (10) facilitates the transfer of the generated mechanical energy by the electric motor (16) to the wheels (22a, 22b) of the EV (10). Generally, the transmission systems (18) used in EVs (10) include single speed transmission system and multi-speed (i.e., two-speed) transmission system, wherein the single speed transmission system comprises a single gear pair whereby the EV (10) is maintained at a constant speed. However, the multi-speed/two-speed transmission system comprises a compound planetary gear system with a double pinion planetary gear set and a single pinion planetary gear set thereby resulting in two different gear ratios which facilitates higher torque and vehicle speed.
[0045] In one embodiment, all data pertaining to the EV (10) and/or charging infrastructure (20) are collected and processed using a remote server (known as cloud) (24), wherein the processed data is indicated to the rider/driver of the EV (10) through a display unit present in the dashboard (26) of the EV (10). In an embodiment, the display unit may be an interactive display unit. In another embodiment, the display unit may be a non-interactive display unit.
[0046] Embodiments explained herein relate to improper connections detection system for a vehicle. In particular, the present disclosure discloses a system and a method for detecting improper connections in battery cells of a battery pack of the vehicle.
[0047] In an aspect, the present disclosure describes a method for detecting improper connections in battery cells of the battery pack. The method includes measuring, by a microcontroller associated with the system, voltage of each of a plurality of battery cells associated with the battery pack configured with the system. The method includes determining, by the microcontroller, a maximum voltage imbalance among the plurality of battery cells based on the measurement. The method includes measuring, by the microcontroller, a rate of change of the maximum voltage imbalance within a predefined time period. The method includes detecting, by the microcontroller, that a magnitude value of the rate of change of the maximum voltage imbalance is greater than a predefined threshold. Further, the method includes detecting, by the microcontroller, the improper connections in one or more battery cells of the plurality of battery cells based on the magnitude value, and updating one or more parameters of the battery pack based on the detection of the improper connections.
[0048] Various embodiments of the present disclosure will be explained in detail with respect to FIGs. 2 and 3.
[0049] The proposed method (200) and system (300) may utilize measurements of cell voltage, temperature, and battery current to identify potential improper connections within a battery pack (304) associated with the system (300). The system (300) may be implemented in a vehicle, for example, an electric vehicle, or any other systems that make use of a battery pack. In an embodiment, as shown in FIG. 3, the system (300) may include a battery management system (BMS), a microcontroller (302), the battery pack (304), battery cells (306), an Analog Front End (AFE) (308), and an external power source (310). The method (200) may be implemented by the microcontroller (302) associated with the system (300).
[0050] The method (200) may conduct measurements of cell voltages across the battery pack (304). Subsequently, the method (200) may compute a maximum voltage imbalance within the battery pack (304) by subtracting a minimum cell voltage from a maximum cell voltage. These two steps may be executed continuously, resulting in a continuous assessment of voltage imbalance at each time step. Further, the method (200) may calculate a rate of change of voltage imbalance at each time step. If a magnitude of the rate of change of voltage imbalance exceeds a predetermined threshold, it indicates the presence of an improper connection within the battery pack (304).
[0051] Given that these calculations are performed at every time step, the method (200) may allow for instantaneous detection of improper connections without a need for extended monitoring periods. By promptly identifying and addressing the improper connections, the method (200) may help in preventing detrimental effects on performance and overall stability of the battery pack (304).
[0052] Further, a threshold for detecting the improper connections may have two levels. A higher threshold may be set to identify cases such as external cell interconnect defects or Circuit Interrupt Device (CID) activation, where an entire cell connection is severed. Conversely, a lower threshold may be designed to detect cell tab cuts, where there is a sudden increase in a Direct Current Internal Resistance (DCIR) magnitude, but the cell connection remains intact.
[0053] The external cell interconnect defect and the CID activation may be distinguished by determining a temperature of a cell casing. The CID activation may occur only under high-pressure conditions, which typically coincide with elevated temperatures. Based on the rate of change of voltage imbalance, the method (200) may determine a number of cells in the battery pack (304) that have the improper connections. Upon detecting these defects, the system (300) may issue alerts immediately.
[0054] The method (200) may identify the improper connections or missing cell connections, and automatically update one or more parameters of the battery pack (304). The one or more parameters may include, but are not limited to, a State of Charge (SoC), a State of Health (SoH), and a State of Energy (SoE). This enables accurate assessment of the battery pack's performance and degradation over time. In addition, depending on the type of defect detected, appropriate safety measures may be implemented within the system (300).
[0055] With reference to FIG. 2, at 202, the method (200) may include detecting if a constant current is flowing through the battery pack (304) configured with the system (300) from an external power source (310). The external power source (310) may be, for example, a current source or a load. If the current flowing through the battery pack (304) from the external power source (310) is not constant, the method (200) may end.
[0056] At 204, if the current flowing through the battery pack (304) from the external power source (310) is constant, the method (200) may include measuring voltage of each of a plurality of battery cells (306) associated with the battery pack (304). The voltage of each of the plurality of battery cells (306) may be measured using an Analog Front End (AFE) (308) in association with a microcontroller (302) of the system (300).
[0057] At 206, the method (200) may include determining a maximum voltage imbalance among the plurality of battery cells (306) based on the measurement of the voltage of each of a plurality of battery cells (306). The maximum voltage imbalance may be determined by detecting a maximum voltage and a minimum voltage of each cell block, and determining a difference between the maximum voltage and the minimum voltage of each cell block. The method (200) may be performed using the microcontroller (302) associated with the system (300).
[0058] At 208, the method (200) may include measuring a rate of change of the maximum voltage imbalance within a predefined time period in response to determining the maximum voltage imbalance among the plurality of battery cells (306).
[0059] At 210, the method (200) may include determining if a magnitude value of the rate of change of the maximum voltage imbalance is greater than a minimum threshold. If the magnitude value of the rate of change of the maximum voltage imbalance is less than the minimum threshold, the method may proceed to step 202.
[0060] At 212, if the magnitude value of the rate of change of the maximum voltage imbalance is greater than the minimum threshold, the method (200) may include determining if the magnitude value of the rate of change of the maximum voltage imbalance is greater than a maximum threshold. Based on the magnitude value, the method (200) may include detecting improper connections in the battery cells (306) and updating one or more parameters of the battery pack (304) based on the detection of the improper connections.
[0061] At 214, if the magnitude value of the rate of change of the maximum voltage imbalance is greater than the maximum threshold, the method (200) may include determining whether a temperature value of each of the battery cells (306) is greater than a maximum limit.
[0062] At 216, if the temperature value of each of the battery cells (306) is greater than the maximum limit, the method (200) may include detecting that a CID is activated in the battery pack (304) and raise and display alerts in a display associated with the system (300).
[0063] At 218, upon detecting the CID activation in the battery pack (304), the method (200) may include facilitating the system (300) to shut down the battery pack (304).
[0064] At 220, if the magnitude value of the rate of change of the maximum voltage imbalance is less than the maximum threshold, the method (200) may include detecting an improper internal connection in the battery cells (306). The improper internal connection in the battery cells (306) may be, for example, a cell internal tab cut. Upon detection of the improper internal connection in the battery cells (306), the system (300) may raise the alert.
[0065] At 222, the method (200) may include determining a number of battery cells (306) with the improper internal connection with respect to the magnitude value of the rate of change of the maximum voltage imbalance.
[0066] At 224, the method (200) may include segregating the number of active battery cells in each cell block based on the number of battery cells (306) with the improper internal connection. The number of active battery cells in each cell block may be segregated to update the one or more parameters of the battery pack (304). The one or more parameters may include, but are not limited to, a SoC, a SoH, and a SoE of the battery pack (304).
[0067] At 226, if the temperature value of each of the battery cells (306) is less than the maximum limit, the method (200) may include detecting an improper external connection between the battery cells (306). The improper external connection between the battery cells (306) may be, for example, an external cell interconnected defect. Upon detecting the improper external connection between the battery cells (306), the system (300) may raise the alert.
[0068] At 228, the method (200) may include determining the number of battery cells (306) with the improper external connection with respect to the magnitude value of the rate of change of the maximum voltage imbalance.
[0069] At 230, the method (200) may include segregating the number of active battery cells in each cell block based on the number of battery cells (306) with the improper external connection. The number of active battery cells in each cell block may be segregated to update the one or more parameters of the battery pack (304).
[0070] Therefore, the proposed method (200) and system (300) may operate instantly, requiring only an application of a constant current pulse through the battery pack (304). The method (200) can be seamlessly integrated into both production and post-production phases, as well as during battery pack operation. Unlike existing methods that rely on voltage-based methods to identify missing connections, which often entail lengthy detection times, the proposed method (200) may swiftly identify issues associated with the battery pack (304). By promptly updating other algorithms regarding missing cells, the method (200) may enable accurate determination of performance and degradation of the battery pack (304), thereby preventing severe imbalance that occurs when detection is delayed.
[0071] Moreover, the method (200) may distinguish CID activation and subsequent restoration of cell connections, and allow for dynamic estimation of performance and degradation of the battery pack (304). The method (200) may distinguish between improper connections, i.e., both internal and external to the cells within the battery pack (304) in a more efficient manner.
[0072] Furthermore, embodiments of the disclosed devices and systems may be readily implemented, fully or partially, in software using, for example, object or object-oriented software development environments that provide portable source code that can be used on a variety of computer platforms. Alternatively, embodiments of the disclosed methods, processes, modules, devices, systems, and computer program product can be implemented partially or fully in hardware using, for example, standard logic circuits or a very-large-scale integration (VLSI) design. Other hardware or software can be used to implement embodiments depending on the speed and/or efficiency requirements of the systems, the particular function, and/or particular software or hardware system, microprocessor, or microcomputer being utilized.
[0073] In this application, unless specifically stated otherwise, the use of the singular includes the plural and the use of “or” means “and/or.” Furthermore, use of the terms “including” or “having” is not limiting. Any range described herein will be understood to include the endpoints and all values between the endpoints. Features of the disclosed embodiments may be combined, rearranged, omitted, etc., within the scope of the invention to produce additional embodiments. Furthermore, certain features may sometimes be used to advantage without a corresponding use of other features.
[0074] While the foregoing describes various embodiments of the disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof. The scope of the disclosure is determined by the claims that follow. The disclosure is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the present disclosure when combined with information and knowledge available to the person having ordinary skill in the art.

ADVANTAGES OF THE PRESENT DISCLOSURE
[0075] The present disclosure provides a system and a method for detecting improper internal and external connections in battery cells of a battery pack during charge and discharge conditions of the battery pack in a more efficient manner.
[0076] The present disclosure provides a system and a method that use cell voltage, temperature, and battery current measurements to determine improper connections of the battery cells.
[0077] The present disclosure accurately and instantaneously estimates battery pack degradation and performance degradation due to increased electrical stress on certain cells in a battery pack caused by improper cell connections in the battery packs.
[0078] The present disclosure provides detailed information about safety risk faults triggered in a battery pack to help designers better understand safety issues in order to design the battery pack accordingly.

List of References:
System (300)
Microcontroller (302)
Battery Pack (304)
Battery Cells (306)
Analog Front End (AFE) (308)
Power Source (310)

, Claims:1. A method (200) for detecting improper connections in battery cells (306) of a battery pack (304), comprising:
measuring (204), by a microcontroller (302) associated with a system (300), voltage of each of a plurality of battery cells (306) associated with the battery pack (304) configured with the system (300);
determining (206), by the microcontroller (302), a maximum voltage imbalance among the plurality of battery cells (306) based on the measurement;
measuring (208), by the microcontroller (302), a rate of change of the maximum voltage imbalance within a predefined time period;
detecting, by the microcontroller (302), that a magnitude value of the rate of change of the maximum voltage imbalance is greater than a predefined threshold;
detecting, by the microcontroller (302), the improper connections in one or more battery cells of the plurality of battery cells (306) based on the magnitude value; and
updating, by the microcontroller (302), one or more parameters of the battery pack (304) based on the detection of the improper connections.

2. The method (200) as claimed in claim 1, wherein measuring (204), by the microcontroller (302), the voltage of each of the plurality of battery cells (306) comprises:
detecting (202), by the microcontroller (302), that a constant current is flowing through the battery pack (304) from an external power source (310); and
measuring, by the microcontroller (302), the voltage of each of the plurality of battery cells (306) associated with a plurality of cell blocks based on the detection of the flow of the constant current.

3. The method (200) as claimed in claim 1, wherein determining (206), by the microcontroller (302), the maximum voltage imbalance among the plurality of battery cells (306) based on the measurement comprises:
detecting, by the microcontroller (302), a maximum voltage and a minimum voltage of each cell block; and
determining, by the microcontroller (302), a difference between the maximum voltage and the minimum voltage of each cell block to determine the maximum voltage imbalance among the plurality of battery cells (306).

4. The method (200) as claimed in claim 1, wherein updating, by the microcontroller (302), the one or more parameters based on the improper connections comprises:
determining (210), by the microcontroller (302), that the rate of change of the voltage imbalance is greater than a minimum threshold;
determining (212), by the microcontroller (302), whether the rate of change of the voltage imbalance is greater than a maximum threshold;
in response to a determination that the rate of change of the voltage imbalance is greater than the maximum threshold, determining (214), by the microcontroller (302), whether a temperature value of each of the plurality of battery cells (306) is greater than a maximum limit; and
in response to a determination that the rate of change of the voltage imbalance is less than the maximum threshold, updating, by the microcontroller, the one or more parameters with a number of active battery cells in each cell block to measure a value of the one or more parameters for each cell block.

5. The method (200) as claimed in claim 4, wherein updating, by the microcontroller (302), the one or more parameters with the number of active battery cells in each cell block to measure the value of the one or more parameters for each cell block comprises:
detecting (220), by the microcontroller (302), an improper internal connection in the one or more battery cells (306);
determining (222), by the microcontroller (302), a number of battery cells (306) with the improper internal connection with respect to the magnitude value of the rate of change of the maximum voltage imbalance; and
segregating (224), by the microcontroller (302), the number of active battery cells in each cell block based on the number of battery cells (306) with the improper internal connection to update the one or more parameters.

6. The method (200) as claimed in claim 4, comprising:
in response to a determination that the temperature value is greater than the maximum limit, detecting (216), by the microcontroller (302), that a cell Circuit Interrupt Device (CID) is activated in the battery pack (304) to facilitate to shut down the battery pack (304); and
in response to a determination that the temperature value is less than the maximum limit, updating, by the microcontroller (302), the one or more parameters with the number of active battery cells in each cell block to measure the value of the one or more parameters for each cell block.

7. The method (200) as claimed in claim 6, wherein updating, by the microcontroller (302), the one or more parameters with the number of active battery cells in each cell block to measure the value of the one or more parameters for each cell block comprises:
detecting (226), by the microcontroller (302), an improper external connection between the one or more battery cells;
determining (228), by the microcontroller (302), the number of battery cells (306) with the improper external connection with respect to the magnitude value of the rate of change of the maximum voltage imbalance; and
segregating (230), by the microcontroller (302), the number of active battery cells in each cell block based on the number of battery cells (306) with the improper external connection to update the one or more parameters.

8. The method (200) as claimed in claim 7, wherein the one or more parameters comprise at least one of: a State of Charge (SoC), a State of Health (SoH), and battery pack protection techniques.

9. A system (300) for detecting improper connections in battery cells (306) of a battery pack (304), comprising:
a microcontroller (302) configured to:
measure voltage of each of a plurality of battery cells (306) associated with the battery pack (304) configured with the system (300);
determine a maximum voltage imbalance among the plurality of battery cells (306) based on the measurement;
measure a rate of change of the maximum voltage imbalance within a predefined time period;
detect that a magnitude value of the rate of change of the maximum voltage imbalance is greater than a predefined threshold;
detect the improper connections in one or more battery cells of the plurality of battery cells (306) based on the magnitude value; and
update one or more parameters of the battery pack (304) based on the detection of the improper connections.

10. The system (300) as claimed in claim 9, wherein each of the plurality of battery cells (306) is associated with a plurality of cell blocks, and wherein each of the plurality of cell blocks is connected with each other in one of: parallel configuration or series configuration.

11. The system (300) as claimed in claim 9, wherein the microcontroller (302) is configured to:
detect a maximum voltage and a minimum voltage of each cell block; and
determine a difference between the maximum voltage and the minimum voltage of each cell block to determine the maximum voltage imbalance among the plurality of battery cells (306).

12. The system (300) as claimed in claim 9, wherein the microcontroller (302) is configured to:
determine that the rate of change of the voltage imbalance is greater than a minimum threshold;
determine whether the rate of change of the voltage imbalance is greater than a maximum threshold;
in response to a determination that the rate of change of the voltage imbalance is greater than the maximum threshold, determine whether a temperature value of each of the plurality of battery cells (306) is greater than a maximum limit; and
in response to a determination that the rate of change of the voltage imbalance is less than the maximum threshold, update the one or more parameters with a number of active battery cells in each cell block to measure a value of the one or more parameters for each cell block.

13. The system (300) as claimed in claim 12, wherein the microcontroller (302) is configured to:
detect an improper internal connection in the one or more battery cells;
determine a number of battery cells (306) with the improper internal connection with respect to the magnitude value of the rate of change of the maximum voltage imbalance; and
segregate the number of active battery cells in each cell block based on the determination of the number of battery cells with the improper internal connection to update the one or more parameters.

14. The system (300) as claimed in claim 12, wherein the microcontroller (302) is configured to:
in response to a determination that the temperature value is greater than the maximum limit, detect that a cell Circuit Interrupt Device (CID) is activated in the battery pack (304) to facilitate to shut down the battery pack (304); and
in response to a determination that the temperature value is less than the maximum limit, update the one or more parameters with the number of active battery cells in each cell block to measure the value of the one or more parameters for each cell block.
15. The system (300) as claimed in claim 14, wherein the microcontroller (302) is configured to:
detect an improper external connection between the one or more battery cells;
determine the number of battery cells (306) with the improper external connection with respect to the magnitude value of the rate of change of the maximum voltage imbalance; and
segregate the number of active battery cells in each cell block based on the determination of the number of battery cells (306) with the improper external connection to update the one or more parameters.