Patent Publication Number: US-2022238926-A1

Title: Bus bar assembly having a temperature sensing interface, battery moudle including the bus bar assembly, and method of manufacturing the battery module

Description:
RELATED APPLICATIONS 
     This application claims the benefit of U.S. Patent Application No. 62/842,960; filed on May 3, 2019; entitled “TEMPERATURE SENSING INTERFACE”; the content of which is incorporated herein by reference. 
    
    
     BACKGROUND 
     The present disclosure relates generally to the field of batteries and battery modules. More specifically, the present disclosure relates to temperature sensors and methods of integrating temperature sensors in batteries and battery modules. 
     This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art. 
     A vehicle that uses one or more battery systems for providing all or a portion of the motive power for the vehicle can be referred to as an xEV, where the term “xEV” is defined herein to include all of the following vehicles, or any variations or combinations thereof, that use electric power for all or a portion of their vehicular motive force. For example, xEVs include electric vehicles (EVs) that utilize electric power for all motive force. As will be appreciated by those skilled in the art, hybrid electric vehicles (HEVs), also considered xEVs, combine an internal combustion engine propulsion system and a battery-powered electric propulsion system, such as 48 volt or 130 volt systems. The term HEV may include any variation of a hybrid electric vehicle. For example, full hybrid systems (FHEVs) may provide motive and other electrical power to the vehicle using one or more electric motors, using only an internal combustion engine, or using both. In contrast, mild hybrid systems (MHEVs) disable the internal combustion engine when the vehicle is idling and utilize a battery system to continue powering the air conditioning unit, radio, or other electronics, as well as to restart the engine when propulsion is desired. The mild hybrid system may also apply some level of power assist, during acceleration for example, to supplement the internal combustion engine. Mild hybrids are typically 96V to 130V and recover braking energy through a belt or crank integrated starter generator. Further, a micro-hybrid electric vehicle (mHEV) also uses a “Stop-Start” system similar to the mild hybrids, but the micro-hybrid systems of a mHEV may or may not supply power assist to the internal combustion engine and operates at xEVs as described above may provide a number of advantages as compared to more traditional gas-powered vehicles using only internal combustion engines and traditional electrical systems, which are typically 12V systems powered by a lead acid battery. For example, xEVs may produce fewer undesirable emission products and may exhibit greater fuel efficiency as compared to traditional internal combustion vehicles and, in some cases, such xEVs may eliminate the use of gasoline entirely, as is the case of certain types of EVs or PEVs. 
     As technology continues to evolve, there is a need to provide improved power sources, particularly battery modules, for such vehicles. For example, in traditional battery module configurations, temperature sensing components may be coupled to a processor of the traditional battery module, such that the processor receives or determines data indicative of a temperature of various portions of the traditional battery module. Unfortunately, integrating traditional temperature sensing components in traditional battery modules may be cumbersome and expensive, and may lead to undesirable affects, such as inaccurate temperature measurements. Accordingly, improved temperature sensors and integration features are desired. 
     SUMMARY 
     Disclosed herein is an apparatus which may address one or more deficiencies known above. A summary of certain embodiments disclosed herein is set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of these certain embodiments and that these aspects are not intended to limit the scope of this disclosure. Indeed, this disclosure may encompass a variety of aspects that may not be set forth below. 
     In an embodiment, disclosed is a bus bar assembly for a battery module having a plurality of electrochemical cells. The bus bar assembly comprising a bus bar carrier configured to receive bus bars to interface with terminals of the plurality of electrochemical cells, a flex circuit disposed on the bus bar carrier, and a temperature sensor welding tab comprising a circuit engagement region secured to the flex circuit and a welding region to be welded to an end of an electrochemical cell. 
     In another embodiment, disclosed is a battery module. The battery module includes a housing, a plurality of electrochemical cells disposed in the housing, the plurality of electrical chemical cells including an electrochemical cell having a terminal end and a terminal of the terminal end, and the bus bar assembly, wherein the temperature sensor welding tab is welded to the terminal end of the electrochemical cell. 
     In yet another embodiment, disclosed is a method of making a battery module including a housing. The method includes placing a plurality of electrochemical cells in the housing, providing a bus bar assembly including a bus bar carrier and a flex circuit disposed on the bus bar carrier, soldering a circuit engagement region of a temperature sensor welding tab to a flexible extension of the flex circuit, placing the bus bar assembly adjacent to the plurality of electrochemical cells, flexing the flexible extension toward the electrochemical cells such that a temperature sensor of the flex circuit is in close proximity to a terminal end of an electrochemical cell of the plurality of electrochemical cells, and welding a welding region of the temperature sensor welding tab to the terminal end of the electrochemical cell. 
     These and other features and advantages of devices, systems, and methods according to this invention are described in, or are apparent from, the following detailed descriptions of various examples of embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       One or more examples of embodiments of the apparatus and methods according to this invention will be described in detail, with reference to the following figures, wherein: 
         FIG. 1  is a perspective view of a vehicle having a battery module configured in accordance with present embodiments to provide power for various components of the vehicle; 
         FIG. 2  is a cutaway schematic view of the vehicle and the battery module of  FIG. 1 ; 
         FIG. 3  is a partial exploded side view of a battery module capable of being used in the vehicle of  FIG. 1 ; 
         FIG. 4  is a perspective view of a bus bar carrier having a flex circuit, for use in the battery module of  FIG. 3 ; 
         FIG. 5  is a top view of the bus bar carrier and flex circuit of  FIG. 4 ; 
         FIG. 6  is a perspective view of a portion of the bus bar carrier and flex circuit of  FIG. 4 ; 
         FIG. 7  is a perspective view of a portion of the bus bar carrier of  FIG. 4 ; 
         FIG. 8  is an expanded top perspective view of a temperature sensor welding tab coupled to the flex circuit of another bus bar carrier; 
         FIG. 9  is an expanded underside perspective view of the temperature sensor welding tab of  FIG. 8  coupled to the flex circuit; and 
         FIG. 10  is a schematic cross-sectional side view of a coupling between a terminal end of an electrochemical cell and a temperature sensor welding tab of a flex circuit disposed on a bus bar carrier, for use in the battery module of  FIG. 3 . 
     
    
    
     It should be understood that the drawings are not necessarily to scale. In certain instances, details that are not necessary to the understanding of the invention or render other details difficult to perceive may have been omitted. It should be understood, of course, that the invention is not necessarily limited to the particular embodiments illustrated herein. 
     DESCRIPTION 
     One or more specific embodiments will be described below. In an effort to provide a concise description of these embodiments, not all features of an actual implementation are described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers&#39; specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. 
     Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure. 
     The battery systems described herein may be used to provide power to various types of electric vehicles (xEVs) and other high voltage energy storage/expending applications (e.g., electrical grid power storage systems). Such battery systems may include one or more battery modules, each battery module having a number of prismatic battery cells (e.g., lithium-ion (Li-ion) electrochemical cells) arranged to provide particular voltages and/or currents useful to power, for example, one or more components of an xEV. 
     Certain battery modules may include temperature sensing features that allow for temperature sensing of one battery cell, or a group of battery cells, within the module. Generally, the temperature sensors relay signals to a control module of the battery module to allow the control module to supervise temperature management of the battery cells. One challenge associated with temperature sensing of battery cells is providing a sufficient surface area of interface between a temperature sensor and a battery cell housing (“can”). Indeed, certain battery cell housing shapes present bigger challenges than others. For instance, flatter battery cells, such as pouch or prismatic battery cells, generally do not have excess surface area for the interface. Thus, sensing maximum cell temperature and reporting it to a battery management system is a challenge with the flat cell can interfaces. It is now recognized that a robust interface method is needed to pass environmental mechanical tests such as vibration and shock tests. 
     Certain of the configurations described herein use a flexible circuit as a voltage and temperature sensing component. In conventional techniques, for instance those associated with use of traditional wire harnesses, thermistors, a particular type of temperature sensor, are potted to a ring terminal that is either fastened or welded to cell terminals or cell cans. However, because flexible circuits use traces and not wire conductors, potting a copper trace is not feasible and would be mechanically weak. 
     One possible method would be to use a pressure sensitive adhesive (PSA) to attach a thermistor tab (which contacts a battery cell) to a flexible circuit. However, the PSA may provide an insufficient bond under certain temperature conditions (e.g., higher operating temperatures) due to small available surface contact when subjected to vibration and shock testing. 
     In one or more implementations, a mechanical joint is formed using solder to anchor the thermistor tab to the flexible circuit. The thermistor tab is designed to have a geometry that facilitates such an attachment. For instance, the thermistor tab geometry may be designed with two bends that each feed through two cutouts in the flexible circuit. The two cutouts are surrounded by conductive pads that are to be generated during the etching process of the flexible circuit. Before installing the thermistor tab, all the conductive pads are masked with solder paste in preparation for a reflow process, which is a particular type of solder process. When the flexible circuit assembly is reflowed, a mechanical joint (which is electrically isolated) is created between solder and the thermistor tab. 
     To help illustrate,  FIG. 1  is a perspective view of a vehicle  10 , which may utilize a regenerative braking system. Although the following discussion is presented in relation to vehicles with regenerative braking systems, the techniques described herein are adaptable to other vehicles that capture/store electrical energy with a battery, which may include electric-powered and gas-powered vehicles; 
     As discussed above, it would be desirable for a battery system  12  to be largely compatible with traditional vehicle designs. Accordingly, the battery system  12  may be placed in a location in the vehicle  10  that would have housed a traditional battery system. For example, as illustrated, the vehicle  10  may include the battery system  12  positioned similarly to a lead-acid battery of a typical combustion-engine vehicle (e.g., under the hood of the vehicle  10 ). Furthermore, as will be described in more detail below, the battery system  12  may be positioned to facilitate managing temperature of the battery system  12 . For example, in some constructions, positioning a battery system  12  under the hood of the vehicle  10  may enable an air duct to channel airflow over the battery system  12  and cool the battery system  12 . 
     A more detailed view of the battery system  12  is described in  FIG. 2 . As depicted, the battery system  12  includes an energy storage component  13  coupled to an ignition system  14 , an alternator  15 , a vehicle console  16 , and optionally to an electric motor  17 . Generally, the energy storage component  13  may capture/store electrical energy generated in the vehicle  10  and output electrical energy to power electrical devices in the vehicle  10 . 
     In other words, the battery system  12  may supply power to components of the vehicle&#39;s electrical system, which may include radiator cooling fans, climate control systems, electric power steering systems, active suspension systems, auto park systems, electric oil pumps, electric super/turbochargers, electric water pumps, heated windscreen/defrosters, window lift motors, vanity lights, tire pressure monitoring systems, sunroof motor controls, power seats, alarm systems, infotainment systems, navigation features, lane departure warning systems, electric parking brakes, external lights, or any combination thereof. Illustratively, in the depicted construction, the energy storage component  13  supplies power to the vehicle console  16  and the ignition system  14 , which may be used to start (e.g., crank) the internal combustion engine  18 . 
     Additionally, the energy storage component  13  may capture electrical energy generated by the alternator  15  and/or the electric motor  17 . In some constructions, the alternator  15  may generate electrical energy while the internal combustion engine  18  is running. More specifically, the alternator  15  may convert the mechanical energy produced by the rotation of the internal combustion engine  18  into electrical energy. Additionally or alternatively, when the vehicle  10  includes an electric motor  17 , the electric motor  17  may generate electrical energy by converting mechanical energy produced by the movement of the vehicle  10  (e.g., rotation of the wheels) into electrical energy. Thus, in some construction, the energy storage component  13  may capture electrical energy generated by the alternator  15  and/or the electric motor  17  during regenerative braking. As such, the alternator  15  and/or the electric motor  17  are generally referred to herein as a regenerative braking system. 
     To facilitate capturing and supplying electric energy, the energy storage component  13  may be electrically coupled to the vehicle&#39;s electric system via a bus  19 . For example, the bus  19  may enable the energy storage component  13  to receive electrical energy generated by the alternator  15  and/or the electric motor  17 . Additionally, the bus  19  may enable the energy storage component  13  to output electrical energy to the ignition system  14  and/or the vehicle console  16 . Accordingly, when a 12-volt battery system  12  is used, the bus  19  may carry electrical power typically between 8-18 volts. 
     Additionally, as depicted, the energy storage component  13  may include multiple battery modules. For example, in the depicted construction, the energy storage component  13  includes a lithium ion (e.g., a first) battery module  20  and a lead-acid (e.g., a second) battery module  22 , which each includes one or more battery cells. In other constructions, the energy storage component  13  may include any number of battery modules. Additionally, although the lithium ion battery module  20  and lead-acid battery module  22  are depicted adjacent to one another, they may be positioned in different areas around the vehicle. For example, the lead-acid battery module  22  may be positioned in or about the interior of the vehicle  10  while the lithium ion battery module  20  may be positioned under the hood of the vehicle  10 . 
     In some constructions, the energy storage component  13  may include multiple battery modules to utilize multiple different battery chemistries. For example, when the lithium ion battery module  20  is used, performance of the battery system  12  may be improved since the lithium ion battery chemistry generally has a higher coulombic efficiency and/or a higher power charge acceptance rate (e.g., higher maximum charge current or charge voltage) than the lead-acid battery chemistry. As such, the capture, storage, and/or distribution efficiency of the battery system  12  may be improved. 
     To facilitate controlling the capturing and storing of electrical energy, the battery system  12  may additionally include a control module  24 . More specifically, the control module  24  may control operations of components in the battery system  12 , such as relays (e.g., switches) within energy storage component  13 , the alternator  15 , and/or the electric motor  17 . For example, the control module  24  may regulate an amount of electrical energy captured/supplied by each battery module  20  or  22  (e.g., to de-rate and re-rate the battery system  12 ), perform load balancing between the battery modules  20  and  22 , determine a state of charge of each battery module  20  or  22 , determine temperature of each battery module  20  or  22 , control voltage output by the alternator  15  and/or the electric motor  17 , and the like. 
     Accordingly, the control unit  24  may include one or more processor  26  and one or more memory  28 . More specifically, the one or more processor  26  may include one or more application specific integrated circuits (ASICs), one or more field programmable gate arrays (FPGAs), one or more general purpose processors, or any combination thereof. Additionally, the one or more memory  28  may include volatile memory, such as random access memory (RAM), and/or non-volatile memory, such as read-only memory (ROM), optical drives, hard disc drives, or solid-state drives. In some constructions, the control unit  24  may include portions of a vehicle control unit (VCU) and/or a separate battery control module. 
       FIG. 3  is a partial exploded, perspective view of a battery module  20  for use in the vehicle  10  of  FIG. 1 . Before proceeding, it should be noted that the battery module  20  may be used in other electrical environments and is not limited to the vehicle  10  of  FIG. 1 . For simplicity, not all components of the battery module  20  are illustrated. The battery module  20  (e.g., lithium-ion (Li-ion) battery module) includes a housing  30  (e.g., plastic housing), a bus bar carrier  32 , a flex circuit  34 , and a cover  36 . A plurality of electrochemical cells  38  (e.g., Li-ion electrochemical cells), otherwise referred to as battery cells when enclosed by an individual battery cell housing, are disposed within the housing  30 . In certain constructions, the battery module  20  may include any number of electrochemical cells  38  (e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10, or more electrochemical cells), any type of electrochemical cell  38  (e.g., Li-ion, lithium polymer, lead-acid, nickel cadmium, or nickel metal hydride, prismatic, and/or cylindrical), and any arrangement of the electrochemical cells  38  (e.g., stacked, separated, or compartmentalized). 
     The housing  30  includes an opening  40  on one side (upper side or face) to receive the electrochemical cells  38 . The bus bar carrier  32  may be disposed within the opening  40  and above the electrochemical cells  38 , and may include bus bars disposed thereon configured to interface with terminals  42  extending from terminal ends  43  of the electrochemical cells  38 . That is, the bus bars may be disposed in locations of the bus bar carrier  32  suitable for coupling the bus bars to the terminals  42  of the electrochemical cells  38 . The bus bar carrier  32  may also include the flex circuit  34  disposed thereon. For example, the flex circuit  34  may be disposed on an upper side  44  of the bus bar carrier  32  opposing an underside  46  of the bus bar carrier  32 . The flex circuit  34  in the illustrated construction is coupled to the upper side  44  of the bus bar carrier  32 . The flex circuit  34  may include a flexible material, such as a polyimide material, within which (and from which) electrical components extend. The electrical components of the flex circuit  34  may be configured to interface with the bus bars and/or with the terminal ends  43  of the electrochemical cells  38 . For example, as will be appreciated in view of further discussion below, the flex circuit  34  may include voltage sensing tabs configured to contact bus bars of the battery module  20 , and temperature sensor welding tabs  49  ( FIG. 4 ) configured to contact the terminal ends  43  of certain ones of the electrochemical cells  38 . Each temperature sensor welding tab may include a metal material, such as aluminum, and may be configured to be welded (e.g., from overhead) to the terminal end  43  of one of the electrochemical cells  38 . The flex circuit  34  may also include electrical contacts  50  extending toward other features disposed in the housing  40 , such as a processor of the battery module  20  or an electrical path to the processor. 
     As set forth above and described in further detailed below, the voltage sensing tabs and the temperature sensor welding tabs  49  may be strategically positioned on the flex circuit  34 , and the flex circuit  34  may be strategically positioned on the bus bar carrier  32 , to enable coupling of the voltage sensing tabs and the temperature sensor welding tabs  49  of the flex circuit  34  with the appropriate features of the battery module  20 . Aspects of the temperature sensor welding tabs  49  will be described in detail below with reference to later drawings. 
       FIG. 4  is a perspective view of the bus bar carrier  32  having the flex circuit  34 . As previously described, the flex circuit  34  may include a thin layer of flexible and electrically insulative material, such as polyimide. The flex circuit  34  may include various electrical components disposed in and/or extending from the polyimide material of the flex circuit  34 . For example, electrical conductors (e.g., traces) may be embedded within and/or printed on the polyimide material of the flex circuit  34 , and may extend between various electrical components of the flex circuit  34 . In the illustrated construction, the flex circuit  34  includes, for example, two temperature sensor welding tabs  49  extending from edges of the flex circuit  34 , among other electrical components. In particular and as shown in further detail in  FIGS. 8 and 9 , the temperature sensor welding tabs  49  are securely fastened to the flex circuit  34  by way of at least one bond formed by reflow soldering. 
     Referring to  FIGS. 4 and 5 , the temperature sensor welding tabs  49  are disposed on portions of the flex circuit  34  that, when the flex circuit  34  is disposed on the bus bar carrier  32 , cause the temperature sensor welding tabs  49  to extend through openings, or windows  51 , in the bus bar carrier  32 . The windows  51  may extend, for example, from the upper side  44  of the bus bar carrier  32  to the underside  46  of the bus bar carrier  32 . That is, the windows  51  extend entirely through a thickness of the bus bar carrier  32 . The windows  51  enable the temperature sensor welding tabs  49  to extend from the flex circuit  34  disposed on the upper side  44  of the bus bar carrier  32  into contact with features (e.g., terminal ends of electrochemical cells) disposed adjacent (e.g., under) the underside  46  of the bus bar carrier  32 . The windows  51  also enable an unobstructed view of the temperature sensor welding tabs  49  from above the bus bar carrier  32 . For example,  FIG. 5  is a top view of the bus bar carrier  32  and the flex circuit  34  of  FIG. 4 . As shown, each temperature sensor welding tab  49  includes a welding region  53  that is unobstructed from view. The welding region  53  may be welded or otherwise adhered to, for example, a terminal end of an electrochemical cell disposed underneath the bus bar carrier  32 . 
       FIGS. 6 and 7  are perspective views of a portion of the bus bar carrier  32  and flex circuit  34  of  FIG. 4 . For example,  FIG. 6  is an overhead perspective view of the portion of the bus bar carrier  32  and the flex circuit  34 , and  FIG. 7  is a bottom perspective view of the portion of the bus bar carrier  32  and the flex circuit  34 . In  FIG. 6 , the flex circuit  34  is illustrated as disposed on the upper side  44  of the bus bar carrier  32 . The bus bar carrier  32  includes the window  51  through which the temperature sensor welding tab  49  extends. As shown in  FIG. 6 , the flex circuit  54  includes a notch  61  between two adjacent extensions  63 ,  65  of the flex circuit  54 , where the temperature sensor welding tab  49  is disposed on the first extension  63  of the two extensions  63 ,  65 . A notch  67  may also be disposed on an opposing side of the first extension  63 . That is, the first extension  63  may be defined by the two notches  61 ,  67 , and may include a rectangular shape or other suitable shape. 
     By disposing the temperature sensor welding tab  49  on the first extension  63 , the first extension  63  may flex downwardly when the temperature sensor welding tab  49  is welded or otherwise adhered to the terminal end of the electrochemical cell. Thus, as set forth above, the temperature sensor welding tab  49  is reliably secured to the flex circuit  34 . For example, as shown, the temperature sensor welding tab  49  includes a circuit engagement region  55 , the welding region  53 , and a transverse region  57  extending transversely between the circuit engagement region  55  and the welding region  53 . That is, in the illustrated construction the temperature sensor welding tab  49  includes a bent plate, where the transverse region  57  is bent relative to the circuit engagement region  55 , and the welding region  53  is bent relative to the transverse region  57 . In other words, the transverse region  57  extends at a non-right angle relative to the circuit engagement region  55  and the welding region  53  to enable passage of the temperature sensor welding tab  49  from the flex circuit  34  on the upper side  44  of the bus bar carrier  32 , through the window  51 , and adjacent the underside  46  (see  FIG. 7 ) of the bus bar carrier  32 . Further, the bend of the temperature sensor welding tab  49  (e.g., between the transverse region  57  and the circuit engagement region  55 , and between the transverse region  57  and the welding region  53 ) enforces a gap between the terminal end of the electrochemical cell and other components (e.g., thermistors) of, or on, the flex circuit  34 . 
       FIG. 7 , the temperature sensor welding tab  49  is illustrated as extending through the window  51 , and being disposed adjacent the underside  44  of the bus bar carrier  32 . That is, the welding region  53  is disposed adjacent the underside  44  of the bus bar carrier  32 , and may be configured to be welded to the terminal end of an electrochemical cell. Further, in  FIG. 7 , thermistors  60  are disposed on the flex circuit  34  adjacent to the temperature sensor welding tab  49 . For example, the thermistors  60  are disposed on an underside  70  of the first extension  65  of the flex circuit  34 . The temperature sensor welding tab  49  may be used, via the coupling (e.g., weld) to the terminal end of the electrochemical cell, to bring the thermistors  60  in close proximity to the terminal end of the electrochemical cell. For example, when the temperature sensor welding tab  49  is coupled to the terminal end of the electrochemical cell, the connection may cause the first extension  63  of the flex circuit  34  to be pulled downwardly, and the thermistors  60  may be disposed on the underside  70  of the first extension  63  of the flex circuit  34 . Thus, the thermistors  60  may be pulled toward, or held in close proximity to, the terminal end of the electrochemical cell via the coupling of the temperature sensor welding tab  49  to the terminal end of the electrochemical cell. 
     In some constructions, the thermistors  60  may be decoupled from the temperature sensor welding tab  49 , but disposed in close proximity to the temperature sensor welding tab  49  (i.e., on the underside  70  of the first extension  63  of the flex circuit  34 ) to enable the above-described effects. In other construction, the thermistors  60  may be electrically coupled to the temperature sensor welding tab  49 . Further, the thermistors  60  may be electrically coupled to electrical conductors (e.g., traces) encapsulated by the polyimide material of the flex circuit  34 , and/or running along an underside of the flex circuit  34  between the flex circuit  34  and the bus bar carrier  32 . The electrical conductors may then couple to electrical contacts  50  (see  FIGS. 4 and 5 ), which may be coupled to a processor or other feature of a printed circuit board or battery module control and/or monitoring assembly. 
     The manner in which a temperature sensor welding tab  49  may be coupled to the flex circuit  34  may be further appreciated with reference to  FIGS. 8 and 9 , which depict expanded views of one of a temperature sensor welding tabs  49  in relation to the flex circuit  34 . In particular,  FIG. 8  depicts an expanded perspective view of an upper side  90  of the flex circuit  34  (i.e., a side that faces away from the electrochemical cells  38 ). In the illustrated construction, the circuit engagement region  55  is disposed against the upper side  90  of the flex circuit  34 . The temperature sensor welding tab  49  includes a first tab  92  and a second tab  94  that extend from the circuit engagement region  55 , for example from opposite sides of the circuit engagement region  55 . That is, the first tab  92  and the second tab  94  may protrude in opposite directions from the circuit engagement region  55 . The first tab  92  and the second tab  94  are also angled with respect to the plane of the circuit engagement region  55  and the flex circuit  34 . That is, the first tab  92  and the second tab  94  each protrude in a first direction away from the circuit engagement region  55 , and then protrude in a second, crosswise direction with respect to the plane of the circuit engagement region  55  and the plane of the flex circuit  34 . This second, crosswise direction of extension may be produced by a bend, curvature, etc., of the first tab  92  and the second tab  94 . 
     The bends of the first tab  92  and the second tab  94  allow them to protrude through the flex circuit  34  at a first via  96  and a second via  98 , respectively. The first tab  92  and the second tab  94  may have any suitable geometry and any suitable dimension, provided that at least some of the techniques presently described for securement with the flex circuit  34  can be performed. 
     The first via  96  and the second via  98  may have any suitable shape and size to accommodate protrusion of the first tab  92  and the second tab  94  through the flex circuit  34  from the upper side  90  to the underside  70 , as shown in  FIG. 9 . In accordance with certain constructions, the first via  96  and the second via  98  may have a perimeter shape and size that is just slightly larger than the cross-sectional size of the first tab  92  and the second tab  94 . For example, the first via  96  and the second via  98  may be sized to allow a robotic placement system to position the flex circuit  34  atop the temperature sensor welding tab  49  in a manner that allows the first tab  92  and the second tab  94  to extend through the flex circuit  34 , without additional operations. 
     As shown in  FIG. 9 , the first tab  92  and the second tab  94  may be secured to the flex circuit  34  using a first solder pad  100  and a second solder pad  102 , respectively. In particular, a paste containing solder may be positioned on the flex circuit  34 . Once the flex circuit  34  is placed atop the temperature sensor welding tab  49  causing the first and second tabs  92 ,  94  to protrude through the flex circuit  34 , the paste is heated by an amount sufficient to cause the solder to flow. Once the solder cools, the first and second tabs  92 ,  94  are secured to the flex circuit  34  by the solder. Such a process may be referred to as a reflow process of soldering. In this respect, the reflow process is used to secure the temperature sensor welding tab  49  to the flex circuit  34 . 
     In certain construction, the reflow process may be performed in a manner that secures several features to the flex circuit  34  at once. For example, referring to the construction illustrated in  FIG. 9 , the reflow process may be used to secure the first and second tabs  92 ,  94 , the temperature sensor  60  (a thermistor) and a capacitor  104  to the flex circuit  34 . Once such features are secured to the flex circuit  34 , the temperature sensor welding tab  49  may be considered ready for attachment to one of the electrochemical cells  38 . Attachment of features in this order may facilitate assembly and manufacturing. However, the present disclosure is not necessarily limited to this order of operations. 
       FIG. 10  is a schematic cross-sectional side view of a construction of a coupling between the terminal end  43  of an electrochemical cell  38  and the temperature sensor welding tab  49  of the present disclosure. As previously described, the temperature sensor welding tab  49  may include the circuit engagement region  55 , the welding region  53 , and the transverse region  57  extending between the circuit engagement region  55  and the welding region  53 . The transverse region  57  may be bent to form an angle with the welding region  53 , and the circuit engagement region  55  may be bent relative to the transverse region  57  to form another angle with the transverse region. By including the transverse region  57  extending at angles relative to the welding region  53  and the circuit engagement region  55 , the welding region  53  may fall flat on the terminal end  43  of the electrochemical cell  38 . The welding region  53  may be coupled to the terminal end  43  of the electrochemical cell  38  such that at least the transverse region  57  of the temperature sensor welding tab  49  is disposed in the window  51  of the bus bar carrier  32 . As shown, a portion (e.g., the first segment  63 ) of the polyimide material of the flex circuit  34  may also extend into (e.g., overlap with) the window  51  of the bus bar carrier  32 , and the thermistors  60  may be disposed on the first segment  63  of the polyimide material of the flex circuit  34 . Thus, the temperature sensor welding tab  49 , when coupled to the terminal end  43  of the electrochemical cell  38 , may cause the first segment  63  of the polyimide material of the flex circuit  34 , and the thermistors  60  coupled to the first segment  63 , to be drawn toward the terminal end  43  of the electrochemical cell  38 . However, in other construction, the welding region  53  may fall flat against the terminal end  43  of the electrochemical cell  38  without substantial bending of the first segment  63  of the polyimide material of the flex circuit  34 . 
     Further, the bend of the temperature sensor welding tab  49  (e.g., between the transverse region  57  and the circuit engagement region  55 , and between the transverse region  57  and the welding region  53 ) enforces a gap between the terminal end  43  of the electrochemical cell  38  and other components (e.g., thermistors  60 ) of, or on, the flex circuit  34 . The gap blocks an interference of the electrochemical cell  38  upon the thermistors  60  and/or other components. 
     The disclosed features of the bus bar carrier  32 , the flex circuit  34 , the temperature sensor welding tabs  49 , and the thermistors  60  may enable improved assembly of the battery module, may reduce a cost of the battery module, and may improve temperature measurements determined by the battery module. 
     As utilized herein, the terms “approximately,” “about,” “substantially,” and similar terms are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. It should be understood by those of skill in the art who review this disclosure that these terms are intended to allow a description of certain features described and claimed without restricting the scope of these features to the precise numerical ranges provided. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and claimed are considered to be within the scope of the invention as recited in the appended claims. 
     It should be noted that references to relative positions (e.g., “top” and “bottom”) in this description are merely used to identify various elements as are oriented in the Figures. It should be recognized that the orientation of particular components may vary greatly depending on the application in which they are used. 
     For the purpose of this disclosure, the term “coupled” means the joining of two members directly or indirectly to one another. Such joining may be stationary in nature or moveable in nature. Such joining may be achieved with the two members or the two members and any additional intermediate members being integrally formed as a single unitary body with one another or with the two members or the two members and any additional intermediate members being attached to one another. Such joining may be permanent in nature or may be removable or releasable in nature. 
     It is also important to note that the construction and arrangement of the system, methods, and devices as shown in the various examples of embodiments is illustrative only. Although only a few embodiments have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter recited. For example, elements shown as integrally formed may be constructed of multiple parts or elements show as multiple parts may be integrally formed, the operation of the interfaces may be reversed or otherwise varied, the length or width of the structures and/or members or connector or other elements of the system may be varied, the nature or number of adjustment positions provided between the elements may be varied (e.g. by variations in the number of engagement slots or size of the engagement slots or type of engagement). The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. Other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the various examples of embodiments without departing from the spirit or scope of the present inventions. 
     While this invention has been described in conjunction with the examples of embodiments outlined above, various alternatives, modifications, variations, improvements and/or substantial equivalents, whether known or that are or may be presently foreseen, may become apparent to those having at least ordinary skill in the art. Accordingly, the examples of embodiments of the invention, as set forth above, are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit or scope of the invention. Therefore, the invention is intended to embrace all known or earlier developed alternatives, modifications, variations, improvements and/or substantial equivalents. 
     The technical effects and technical problems in the specification are exemplary and are not limiting. It should be noted that the embodiments described in the specification may have other technical effects and can solve other technical problems.