Temperature sensing within a battery pack

Abstract

Techniques for sensing temperature at different locations within a battery pack are described. In an example, the battery pack comprises a plurality of battery modules (104). The plurality of battery modules (104) comprises a plurality of battery cells (106). The battery modules (104) are secured within a cell holder (102). At least one busbar (108) is arranged on the cell holder (102). The battery pack comprises at least one busbar (108) that is configured to establish an electrical connection amongst the plurality of battery modules (104). The battery pack further comprises a harness (110) disposed on the at least one busbar (108). The harness (110) is disposed on the at least one busbar (108) using a plurality of harness holding features (114) to securely hold the harness (110). Further, at least one temperature sensor is disposed on the harness (110). The at least one temperature sensor may be positioned at any position along the length of the harness (110).

Description

TEMPERATURE SENSING WITHIN A BATTERY PACKTECHNICAL FIELD

[0001] The present subject matter relates, in general, to battery packs and, in particular, to a method and system for temperature sensing at different locations within a battery pack.BACKGROUND

[0002] Electric vehicles and hybrid electric vehicles are powered by onboard rechargeable battery packs. The performance and safety of the battery packs is affected by various parameters. One of the parameters that affects the performance and safety of a battery packs is the temperature of the battery pack. Technologies have thus been developed to determine the temperature of the battery pack to ensure that the battery pack operates within a predetermined temperature range.BRIEF DESCRIPTION OF DRAWINGS

[0003] The detailed description is provided with reference to the accompanying figures, wherein:

[0004] FIG. 1 illustrates schematic of a battery pack for facilitating temperature sensing at different locations within the battery pack, in accordance with an example of the present subject matter.

[0005] FIGs. 2a and 2b illustrate top perspective view of the battery pack for facilitating temperature sensing at different locations within the battery pack, in accordance with another example of the present subject matter, and

[0006] FIG. 3 illustrates a method for temperature sensing at different locations within the battery pack, in accordance with an example of the present subject matter.DETAILED DESCRIPTION

[0007] A battery pack includes a plurality of battery cells arranged in series and parallel configurations. The configuration of the plurality of battery cells may be determined based on the desired voltage and capacity of the battery pack. The battery cells are further grouped into a plurality of battery modules. Further, the battery pack includes a cell holder that secures the plurality of battery modules in place for maintaining alignment and structural integrity of the battery pack. The battery pack further includes busbars that serve as the main electrical pathway between the plurality of battery modules and connect the plurality of battery modules in series or parallel configurations to create a single electrical unit with the desired voltage and capacity.

[0008] Since the battery pack is provided with a plurality of battery cells, the temperature within the battery pack is often unevenly distributed. That is, the temperature at different locations within the battery pack may be different. When the temperature of the battery cell in the battery pack is extremely high, as the battery cell is made of flammable metals such as lithium, continuing to use the battery cell may cause the temperature to rise further, which may cause the battery cell to burst. On the other hand, when the temperature of the battery cell is extremely low, the activity of the battery cell diminishes. Continuing to charge or discharge the battery cell at low temperatures may potentially result in irreversible damage to the battery cell, affecting the overall performance and lifespan of the battery pack.

[0009] Accordingly, temperature data can be used to diagnose potential issues within the battery pack. For instance, if a specific area shows consistently higher temperatures, it may indicate a problem with that section. Analyzing the temperature data enables targeted maintenance actions or replacement to address specific issues and enhance battery performance. Monitoring and managing the temperature of the battery pack thus prevents thermal runaway, enhances the efficiency of the battery pack, and ensures the safety of the device or vehicle that the battery pack powers.

[0010] In conventional techniques, the temperature at multiple locations within a battery pack is measured using temperature sensors. The temperature sensors are traditionally installed on the printed circuit boards (PCBs) located within the battery pack. For instance, if the battery pack contains two PCBs, each PCB may have an attached temperature sensor. The PCBs are typically positioned at the edge or side of the battery pack to reduce the overall size and to simplify maintenance.

[0011] However, the temperature is often highest at the centre of the battery pack due to heat generated by the battery cells. Thus, placing a temperature sensor at the centre allows accurate temperature measurement. Since the temperature sensors are usually included in PCBs, measuring the temperature of the battery cell located at the centre of the battery pack entails installation of a PCB at the centre of the battery pack.

[0012] However, installing a PCB at the centre may increase the overall size of the battery pack, complicate the assembly process, and affect manufacturing efficiency. Further, the central positioning of the PCB may lead to heat accumulation, which could pose a risk of thermal management issues. Additionally, accessing the PCB for inspection, maintenance, or repair may be difficult due to its central location. The placement of PCB at the centre of the battery pack may also increase the likelihood of electrical interference between the PCB and adjacent battery cells, thereby impacting the overall performance and reliability of the battery pack.

[0013] According to examples of the present subject matter, techniques for sensing temperature at different locations within a battery pack are described.

[0014] In an example, the battery pack comprises a plurality of battery modules. Each of the plurality of battery modules further comprises a plurality of battery cells. The battery pack further comprises a cell holder, where the cell holder securely holds the plurality of battery modules.

[0015] The battery pack further comprises at least one busbar arranged on the cell holder, where the at least one busbar is configured to establishan electric connection amongst the plurality of battery modules. Further, the battery pack comprises a harness disposed on the at least one busbar. The battery pack further comprises at least one temperature sensor, where the at least one temperature sensor is disposed on the harness.

[0016] The placement of the at least one temperature sensor on the harness disposed over the busbar may enable a more integrated and efficient approach to thermal monitoring within the battery pack. Particularly, by leveraging the harness as a mounting platform, the temperature sensors can be positioned at strategic locations across the battery pack without requiring additional structural components or complex routing. Accordingly, the present subject matter allows for sensing of temperature variations at different critical points within the battery back, thereby enhancing safety and performance monitoring of the battery pack.

[0017] The manner in which the temperature sensing at different locations of the battery pack is implemented is explained in detail with respect to FIGs. 1 -3. While aspects of the described battery pack may be implemented in any number of different electronic devices, environments, and / or implementation, the examples are described in the context of the following example device (s). It may be noted that drawings of the present subject matter shown here are for illustrative purposes and are not to be construed as limiting the scope of the subject matter claimed.

[0018] FIG. 1 illustrates schematics of a battery pack 100, in accordance with an example of the present subject matter. The battery pack 100 may be used in various applications, including but not limited to, electric vehicles (EVs) and hybrid electric vehicles (HEVs).

[0019] The battery pack 100 comprises a plurality of battery modules 104-1 , 104-2, ... , 104-n. Further, each of the battery modules 104-1 , 104-2, ... , 104-n comprises a plurality of battery cells. For instance, as illustrated, the battery module 104-1 may include a plurality of battery cells 106-1 -1 , 106-1 -22, ... .,106-1 -N. Similarly, the battery module 104-2 may include a plurality of battery cells 106-2-1 , 106-2-2, ... , 106-2-N. Further, the batterymodule 104-N may include a plurality of battery cells 106-N-1 , 106-N-2, ... , 106-N-N. The battery cells may be the primary electrochemical units responsible for storing and delivering electrical energy. The battery cells within each module may be electrically connected in series and / or parallel configurations to achieve the desired voltage and capacity.

[0020] The battery pack further comprises a cell holder 102. The cell holder 102 securely holds the plurality of battery modules 104. The cell holder may ensure that the battery modules 104 are maintained in a fixed position, thereby preserving their alignment and preventing displacement due to vibrations, thermal expansion, or mechanical shocks during operation or transportation. In one example, the cell holder 102 is made of a high-strength, electrically insulating material such as a glass-filled nylon or polypropylene composite. The material of the cell holder 102 is selected to provide mechanical rigidity while also offering thermal resistance and electrical isolation between adjacent modules. Further, the cell holder 102 facilitates efficient thermal management by allowing airflow or integration of cooling channels around the battery modules 104. The cell holder 102 may also include features such as slots, ribs, or clips to guide the placement of modules and to simplify assembly and maintenance procedures.

[0021] The battery pack 100 further comprises at least one busbar 108 arranged on the cell holder 102. The cell holder 102 serves as a mounting platform for the at least one busbar 108. In one example, the at least one busbar 108 may be composed of a conductive element, such as copper or aluminum, selected for its high electrical conductivity and low resistance. The at least one busbar 108 may be configured to establish an electric connection amongst the plurality of battery modules 104, thereby ensuring efficient current distribution within the battery pack 100. The at least one busbar 108 may further include multiple contact terminals or tabs that interface with the plurality of battery modules 104, and may be coated with an insulating layer to prevent accidental short circuits.

[0022] The battery pack 100 further comprises a harness 110 disposed on the at least one busbar 108. The harness 110 may be placed at different locations within the battery pack. For instance, in an example, the harness 110 may be positioned at center of the cell holder 102. FIG. 2a illustrates a top perspective view of the battery pack. As illustrated in FIG. 2a, the harness may be disposed at center of the cell holder 102 of the battery pack. In another example, the harness 110 may be positioned at an edge of the battery pack.

[0023] Further, the battery pack 100 may include at least one temperature sensor disposed on the harness 110. Examples of temperature sensors include, but are not limited to, thermistors, resistor temperature detectors, infrared sensors, thermocouples, etc. One of the commonly used thermistors in a battery pack is an NTC (Negative Temperature Coefficient) thermistor. An NTC thermistor may be a type of resistor whose resistance decreases as temperature increases. The NTC thermistor is used for precise temperature measurements and current-limiting applications in electronic circuits. The thermistor is made from ceramics or polymers, which determine its temperature response characteristics. The NTC thermistor operates effectively within a temperature range of -55°C to +200°C.

[0024] The at least one temperature sensor may be positioned at any position along the length of the harness 110. As illustrated in FIG. 2b, by positioning the at least one temperature sensor 106 on the harness 110 as indicated by 204, the temperature of the battery cells 106 along the harness 110 can be determined.

[0025] In an example, when the harness 110 is positioned at the centre of the cell holder 102 of the battery pack 100 and the temperature of the battery cells 106 situated in the centre of the cell holder 102 is to be measured, where temperatures are typically the highest within the battery pack 100, the temperature sensor 112 positioned along the harness 110 of the battery pack 100 can be utilized. Further, when the harness 110 is positioned at the edge of the battery pack 100 and the temperature of thebattery cells 106 situated in the edge of the battery pack is to be measured, the at least one temperature sensor 112 positioned along the harness 110 of the battery pack 100 can be utilized.

[0026] In an example, the harness 110 may be disposed on the at least one busbar 108 using a plurality of harness holding features 114-1 , 114-2, 114-3, ... , 114-n. For the ease of reference, the plurality of harness holding features 114-1 , 114-2, 114-3, ... , 114-n has been referred to as plurality of harness holding features 114, hereinafter.

[0027] The plurality of harness holding features 114 may be made using a thermoplastic blended material. The thermoplastic blended material may be selected for making the plurality of harness holding features 114 due to its excellent mechanical strength, thermal stability, and electrical insulation properties. In one example, the thermoplastic blended material may include a blend of polybutylene terephthalate (PBT) and polycarbonate (PC). In another example, the thermoplastic blended material may include a blend of polycarbonate (PC) and acrylonitrile butadiene styrene (ABS) (PC-ABS). The thermoplastic blended material offers a balance of rigidity and impact resistance, making it suitable for automotive and industrial battery applications. The selection of the thermoplastic blended material may further be driven by its ability to withstand high operating temperatures and exposure to chemicals typically present in battery environments. Additionally, the thermoplastic blended material exhibits low moisture absorption, ensuring dimensional stability over time, which is critical for maintaining secure harness placement.

[0028] In one example, each of the plurality of harness holding features 114 may be designed with a snap-fit mechanism that allows the harness 110 to be securely retained without the need for additional fasteners. In the example, each of the plurality of harness holding feature may include flexible arms with inward-facing hooks that may securely grip the harness, enabling quick assembly and disassembly during maintenance or replacement.

[0029] In an example, the battery pack 100 may further include a printed circuit board (PCB) 202. As illustrated in FIG. 2a, the PCB 202 may be disposed on at least one edge of the cell holder 102. In the example, a temperature sensor may be disposed on the PCB 202 to detect the temperature of the plurality of battery cells arranged near the edges of the housing of the battery pack. By placing a temperature sensor on the PCB 202 arranged at the edge of the cell holder along with various other temperatures sensors disposed at different other locations on the top cell holder, a more comprehensive thermal profile of the battery pack may be obtained.

[0030] The battery pack further includes a battery management system (BMS) 116 to monitor and manage the performance of the battery pack 100. The BMS 116 may be configured to receive temperature data from the at least one temperature sensor 112 disposed on the harness 110. In an example, in addition to receiving the temperature data from the at least one temperature sensor 112, the BMS 116 may further be configured to receive temperature data from the temperature sensor disposed on the PCB 202. The BMS 116 may utilize the temperature data to monitor the temperature of the battery pack 100 and potentially initiate corrective actions if the temperature data indicates abnormal temperature conditions within the battery pack. For example, the BMS 116 may monitor the temperature of the battery pack to identify a situation where the temperature of the battery pack goes above a threshold value. In such a situation, the BMS 116 may activate a cooling system, reduce the charging rate, or temporarily shut down specific battery modules to prevent overheating. Similarly, the BMS 116 may identify a situation where the temperature of the battery falls below a threshold value. In such a situation, the BMS 116 may increase the temperature of the battery pack. For example, the BMS 116 may activate internal heating elements, adjust the load distribution, or modify the operating parameters to raise the temperature to an optimal level.

[0031] FIG. 3 illustrates a method 300 for temperature sensing in a battery pack, in accordance with an example of the present subject matter. At block 302, at least one temperature sensor is positioned on a harness disposed on at least one busbar of the battery pack. The at least one busbar is disposed on a cell holder configured to securely hold a plurality of battery modules of the battery pack, where each of the battery modules comprises a plurality of battery cells. In an example, the harness may be disposed at different locations on the cell holder. For instance, in an example, the harness may be disposed at the center of the cell holder. In another example, the harness may be disposed at an edge of the cell holder. Accordingly, the at least one temperature sensor may be enabled to monitor temperature at different locations within the battery pack.

[0032] At block 304, temperature data is collected from the at least one temperature sensor. The at least one temperature sensor may continuously monitor the temperature at different locations within the battery pack.

[0033] At block 306, the temperature data is analyzed to determine that a temperature of the battery pack is beyond a threshold value. The analysis may include, but is not limited to, detecting temperature variations, identifying potential hotspots, and determining if any areas of the battery pack are operating outside of optimal temperature ranges.

[0034] At block 308, based on the analysis, a corrective action is initiated to optimize the temperature of the battery pack. The corrective action may include adjusting charging or discharging rates, activating cooling systems, or triggering safety protocols if temperatures exceed predefined thresholds. In one example, when it is determined that the temperature of the battery pack is above the threshold value, the temperature of the battery pack is reduced. In another example, when it is determined that the temperature of the battery pack is below the threshold values, the temperature of the battery pack is increased.

[0035] Although implementations of present subject matter have been described in language specific to structural features and / or methods, it is tobe noted that the present subject matter is not necessarily limited to the specific features or methods described. Rather, the specific features and methods are disclosed and explained in the context of a few implementations for the present subject matter.

Claims

I / WE CLAIM:1 . A battery pack comprising: a plurality of battery modules (104), wherein each of the battery modules comprises a plurality of battery cells (106); a cell holder (102) configured to securely hold the plurality of battery modules; at least one busbar (108) arranged on the cell holder (102), wherein the at least one busbar (108) is configured to establish an electrical connection amongst the plurality of battery modules; a harness (110) disposed on the at least one busbar (108); and at least one temperature sensor disposed on the harness (110).

2. The battery pack as claimed in claim 1 , further comprising a plurality of harness holding features (114) disposed on the at least one busbar (108), wherein the plurality of harness holding features (114) is to securely hold the harness (110).

3. The battery pack as claimed in claim 2, wherein each of the plurality of harness holding features (114) is composed of a thermoplastic blended material.

4. The battery pack as claimed in claim 1 , wherein the harness (110) is positioned at centre of the cell holder (102).

5. The battery pack as claimed in claim 1 , wherein the harness (110) is positioned at an edge of the cell holder (102).

6. The battery pack as claimed in claim 1 , further comprising a battery management system (116) configured to: receive temperature data from the at least one temperature sensor disposed on the harness (110); anddetermine a temperature of the battery pack to be beyond a threshold value; and initiate a corrective action to optimize the temperature.

7. The battery pack as claimed in claim 6, wherein the battery management system (116) is configured to optimize the temperature of the battery pack.

8. A method for temperature sensing in a battery pack, comprising: positioning at least one temperature sensor on a harness (110) disposed on at least one busbar (108) of the battery pack, wherein the at least one busbar (108) is disposed on a cell holder (102) configured to securely hold a plurality of battery modules of the battery pack, wherein each of the battery modules comprises a plurality of battery cells (106); collecting temperature data from the at least one temperature sensor; analyzing the temperature data to determine that a temperature of the battery pack is beyond a threshold value; and initiating a corrective action to optimize the temperature of the battery pack.

9. The method as claimed in claim 8, wherein the determining comprises determining that the temperature of the battery pack is above the threshold value, and wherein the corrective action comprises at least one action to reduce the temperature of the battery pack.

10. The method as claimed in claim 8, wherein the determining comprises determining that the temperature of the battery pack is below the threshold value, and wherein the corrective action comprises at least one action to increase the temperature of the battery pack.

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