Thermal exchange assembly for vehicle battery

A battery assembly according to a non-limiting aspect of the present disclosure includes, among other things, a housing, an array of battery cells provided within the housing, and a thermal exchange assembly adjacent the array and including an inlet, an outlet, and a tube configured to direct fluid from the inlet to the outlet. Further, the tube is overmolded with the housing. This disclosure also relates to a method of forming a battery assembly.

BACKGROUND

This disclosure relates to a battery assembly for an electrified vehicle. The battery assembly has a thermal exchange assembly, which includes tubes overmolded with a housing of the battery assembly.

The need to reduce automotive fuel consumption and emissions is well known. Therefore, vehicles are being developed that reduce or completely eliminate reliance on internal combustion engines. Electrified vehicles are one type of vehicle being developed for this purpose. In general, electrified vehicles differ from conventional motor vehicles because they are selectively driven by battery powered electric machines. Conventional motor vehicles, by contrast, rely exclusively on an internal combustion engine to propel the vehicle.

A high voltage battery pack for powering electric machines and other electrical loads typically includes multiple battery cells. The battery cells give off heat during charging and discharging operations. It is often desirable to dissipate this heat from the battery pack to improve the capacity and life of the battery cells.

SUMMARY

A battery assembly according to a non-limiting aspect of the present disclosure includes, among other things, a housing, an array of battery cells provided within the housing, and a thermal exchange assembly adjacent the array and including an inlet, an outlet, and a tube configured to direct fluid from the inlet to the outlet. Further, the tube is overmolded with the housing.

In a further non-limiting embodiment of the foregoing battery assembly, the inlet includes an inlet plenum, the outlet includes an outlet plenum, and the tube is one of a plurality of tubes configured to direct fluid from the inlet plenum to the outlet plenum.

In a further non-limiting embodiment of any of the foregoing battery assemblies, the assembly further includes a thermal transfer plate overmolded with the housing and provided between the plurality of tubes and the array.

In a further non-limiting embodiment of any of the foregoing battery assemblies, the assembly further includes an electromagnetic compatibility (EMC) shield including a plurality of walls projecting from the thermal transfer plate.

In a further non-limiting embodiment of any of the foregoing battery assemblies, the assembly further includes a return plenum provided at an opposite end of the housing than the inlet and outlet plenums.

In a further non-limiting embodiment of any of the foregoing battery assemblies, the plurality of tubes includes a plurality of inlet-side tubes configured to direct fluid from the inlet plenum to the return plenum, and the plurality of tubes includes a plurality of outlet-side tubes configured to direct fluid from the return plenum to the outlet plenum.

In a further non-limiting embodiment of any of the foregoing battery assemblies, each of the inlet-side tubes and the outlet-side tubes are substantially straight tubes extending in a direction substantially parallel to a length of the battery assembly.

In a further non-limiting embodiment of any of the foregoing battery assemblies, each of the plurality of tubes is a single tube including an inlet side, a turning section, and an outlet side.

In a further non-limiting embodiment of any of the foregoing battery assemblies, a first one of the plurality of tubes defines a first tube perimeter, and a second one of the plurality of tubes is provided entirely within the first tube perimeter.

In a further non-limiting embodiment of any of the foregoing battery assemblies, the assembly further includes a plurality of die setting brackets connecting the first tube to the second tube. Further, a first one of the die setting brackets projects from a first side of the first tube to a first side of the second tube, a second one of the die setting brackets projects from a second side of the first tube to a second side of the second tube, and the first sides of the first and second tubes are opposite the second sides of the first and second tubes.

In a further non-limiting embodiment of any of the foregoing battery assemblies, the first tube is one of a first set of tubes configured to direct fluid from the inlet plenum to the outlet plenum in a first direction, and the second tube is one of a second set of tubes configured to direct fluid from the inlet plenum to the outlet plenum in a second direction opposite the first direction.

In a further non-limiting embodiment of any of the foregoing battery assemblies, each of the plurality of tubes are laterally spaced-apart from one another.

In a further non-limiting embodiment of any of the foregoing battery assemblies, each of the plurality of tubes are substantially the same size and shape.

A method of forming a battery assembly according to a non-limiting aspect of the present disclosure includes, among other things, overmolding a tube of a thermal exchange assembly with a housing of the battery assembly.

In a further non-limiting embodiment of the foregoing method, the tube is initially formed with a closed end.

In a further non-limiting embodiment of any of the foregoing methods, the method further includes forming a plenum by machining the housing and a closed end of the tube.

In a further non-limiting embodiment of any of the foregoing methods, the tube is a first tube, the thermal exchange assembly includes a second tube overmolded with the housing, and the first and second tubes are connected by a first die setting bracket and a second die setting bracket arranged to allow material to flow around the thermal exchange assembly during the overmolding step.

In a further non-limiting embodiment of any of the foregoing methods, the first die setting bracket projects from a first side of the first tube to a first side of the second tube, and the second die setting bracket projects from a second side of the second tube to a second side of the second tube. Further, the second sides are opposite the first sides.

In a further non-limiting embodiment of any of the foregoing methods, the method further includes arranging the first tube to define a first perimeter, and arranging the second tube within the first perimeter.

In a further non-limiting embodiment of any of the foregoing methods, the method further includes arranging the second tube such that the second tube is laterally-spaced apart from the first tube.

DETAILED DESCRIPTION

This disclosure relates to an assembly for an electrified vehicle. The assembly may be a battery assembly that includes a thermal exchange assembly for thermally managing heat generated by battery cells of the battery assembly. In one example, the thermal exchange assembly includes an inlet, an outlet, and a tube configured to direct fluid from the inlet to the outlet. Further, the tube is overmolded with a housing of the battery assembly. Such an arrangement integrates the tube directly into the battery assembly housing, which reduces the number of required mechanical connections and assembly steps. In turn, the arrangement reduces the likelihood of fluid leaks and reduces the size of the overall assembly. As such, fluid can be directed through the assembly at higher pressures and increased flow rates, which increases heat transfer. These and other features are discussed in greater detail in the following paragraphs of this detailed description.

FIG. 1schematically illustrates a powertrain10for an electrified vehicle12. Although depicted as a hybrid electric vehicle (HEV), it should be understood that the concepts described herein are not limited to HEVs and could extend to other electrified vehicles, including, but not limited to, plug-in hybrid electric vehicles (PHEVs) and battery electric vehicles (BEVs).

In one embodiment, the powertrain10is a power-split powertrain system that employs a first drive system and a second drive system. The first drive system includes a combination of an engine14and a generator18(i.e., a first electric machine). The second drive system includes at least a motor22(i.e., a second electric machine), the generator18, and a battery assembly24. In this example, the second drive system is considered an electric drive system of the powertrain10. The first and second drive systems generate torque to drive one or more sets of vehicle drive wheels28of the electrified vehicle12. Although a power-split configuration is shown, this disclosure extends to any hybrid or electric vehicle including full hybrids, parallel hybrids, series hybrids, mild hybrids or micro hybrids.

The engine14, which in one embodiment is an internal combustion engine, and the generator18may be connected through a power transfer unit30, such as a planetary gear set. Of course, other types of power transfer units, including other gear sets and transmissions, may be used to connect the engine14to the generator18. In one non-limiting embodiment, the power transfer unit30is a planetary gear set that includes a ring gear32, a sun gear34, and a carrier assembly36.

The generator18can be driven by the engine14through the power transfer unit30to convert kinetic energy to electrical energy. The generator18can alternatively function as a motor to convert electrical energy into kinetic energy, thereby outputting torque to a shaft38connected to the power transfer unit30. Because the generator18is operatively connected to the engine14, the speed of the engine14can be controlled by the generator18.

The ring gear32of the power transfer unit30may be connected to a shaft40, which is connected to vehicle drive wheels28through a second power transfer unit44. The second power transfer unit44may include a gear set having a plurality of gears46. Other power transfer units may also be suitable. The gears46transfer torque from the engine14to a differential48to ultimately provide traction to the vehicle drive wheels28. The differential48may include a plurality of gears that enable the transfer of torque to the vehicle drive wheels28. In one embodiment, the second power transfer unit44is mechanically coupled to an axle50through the differential48to distribute torque to the vehicle drive wheels28.

The motor22can also be employed to drive the vehicle drive wheels28by outputting torque to a shaft52that is also connected to the second power transfer unit44. In one embodiment, the motor22and the generator18cooperate as part of a regenerative braking system in which both the motor22and the generator18can be employed as motors to output torque. For example, the motor22and the generator18can each output electrical power to the battery assembly24.

The battery assembly24is an exemplary electrified vehicle battery. The battery assembly24may be a high voltage traction battery pack that includes a plurality of battery assemblies25(i.e., battery arrays or groupings of battery cells) capable of outputting electrical power to operate the motor22, the generator18and/or other electrical loads of the electrified vehicle12. Other types of energy storage devices and/or output devices can also be used to electrically power the electrified vehicle12.

In one non-limiting embodiment, the electrified vehicle12has two basic operating modes. The electrified vehicle12may operate in an Electric Vehicle (EV) mode where the motor22is used (generally without assistance from the engine14) for vehicle propulsion, thereby depleting the battery assembly24state of charge up to its maximum allowable discharging rate under certain driving patterns/cycles. The EV mode is an example of a charge depleting mode of operation for the electrified vehicle12. During EV mode, the state of charge of the battery assembly24may increase in some circumstances, for example due to a period of regenerative braking. The engine14is generally OFF under a default EV mode but could be operated as necessary based on a vehicle system state or as permitted by the operator.

The electrified vehicle12may additionally operate in a Hybrid (HEV) mode in which the engine14and the motor22are both used for vehicle propulsion. The HEV mode is an example of a charge sustaining mode of operation for the electrified vehicle12. During the HEV mode, the electrified vehicle12may reduce the motor22propulsion usage in order to maintain the state of charge of the battery assembly24at a constant or approximately constant level by increasing the engine14propulsion usage. The electrified vehicle12may be operated in other operating modes in addition to the EV and HEV modes within the scope of this disclosure.

FIG. 2illustrates a battery assembly54that can be incorporated into an electrified vehicle. For example, the battery assembly54could be employed within the electrified vehicle12ofFIG. 1. The battery assembly54includes one battery array56, which is a grouping of battery cells, for supplying electrical power to the electric machine and various other vehicle components. Although one battery array56is illustrated inFIG. 2, the battery assembly54could include multiple battery arrays. In other words, this disclosure is not limited to the specific configuration shown inFIG. 2.

The battery array56includes a plurality of battery cells58that may be stacked adjacent one another in a direction of the length L of the battery array56. Although not shown inFIG. 2, the battery cells58are electrically connected to one another using busbar assemblies. In one embodiment, the battery cells58are prismatic, lithium-ion cells. However, battery cells having other geometries (cylindrical, pouch, etc.) and/or other chemistries (nickel-metal hydride, lead-acid, etc.) could alternatively be utilized within the scope of this disclosure.

An enclosure assembly60surrounds the battery array56. The enclosure assembly60includes a housing62for housing the battery array56and, potentially, any other components of the battery assembly54. In one non-limiting embodiment, the housing62is a tray surrounding a lower portion of the battery array56. The enclosure assembly60may further include one or more covers which, together with the tray, fully surround the battery array56. The enclosure assembly60may take any size, shape or configuration, and is not limited to the specific configuration ofFIG. 2.

During some conditions, heat may be generated by the battery cells58of the battery array56during charging and discharging operations. Heat may also be transferred into the battery cells58during vehicle key-off conditions as a result of relatively hot ambient conditions. During other conditions, such as relatively cold ambient conditions, the battery cells58may need to be heated. A thermal management system64may therefore be utilized to thermally condition (i.e., heat or cool) the battery cells58.

The thermal management system64, for example, may include a fluid source66and at least one thermal exchange assembly68. An example thermal exchange assembly68is shown inFIGS. 3-4. In some examples the thermal exchange assembly68may be referred to as a cold plate assembly, although in some embodiments of this disclosure the thermal exchange assembly68does not truly include a plate.

FIG. 3is a view of the battery assembly54with the housing62drawn partially transparent for purposes of illustration only. InFIG. 3, the example thermal exchange assembly68is arranged adjacent the battery array56, and includes an inlet70, an outlet72, and at least one tube configured to direct fluid F from the inlet70to the outlet72. The inlet70and outlet72are fluidly coupled to the fluid source66. In the example ofFIG. 3, there are six tubes74A-74F between the inlet and outlet70,72. It should be understood that this disclosure extends to thermal exchange assemblies having one or more tubes. Further, it should be understood that the fluid F could be any type of coolant, including glycol for example.

The tubes74A-74F are overmolded with the housing62. Overmolding is the process of adding material over an already-existing piece or part using a molding process. The result is an integrated component including the original piece and the additional material added via the overmolding process. Here, the thermal exchange assembly68is the original piece, and the housing62is provided by molding additional material over the tubes74A-74F. The method of making the battery assembly54will be described in more detail below.

In the example ofFIG. 3, each of the tubes74A-74F is a provided by a single, continuous tube. For example, the tube74A includes an inlet side76, a turning section78, and an outlet side80. In this example, the inlet70is provided adjacent a first end82of the battery assembly54. The inlet side76of the tube74A extends from the inlet70along a first side84of the battery assembly54in a direction of the length L to a location adjacent a second end86of the battery assembly54. The turning section78extends in a direction of the width W of the battery assembly54from a location adjacent a first side84of the battery assembly54to a second side88. The outlet side80of the tube74A extends along the second side88in the direction of the length L from the second end86to the first end82, where the outlet72is located. While only the tube74A is described above, it should be understood that each of the tubes74A-74F includes an inlet side, a turning section, and an outlet side configured to direct fluid F within the battery assembly54from the inlet70to the outlet72.

In the example ofFIG. 3, each of the tubes74A-74F is a different size. For example, the tube74A is the outermost one of the tubes74A-74F and defines a first tube perimeter, which includes the inlet side76, turning section78, and outlet side80. The tube74B is spaced-apart inwardly from the tube74A, and is provided entirely within the first tube perimeter defined by the tube74A. Tube74C is likewise spaced-apart inwardly from the tube74B, and so on.

The tubes74A-74F are provided with fluid F from the inlet70via a plenum, and likewise the tubes74A-74F return the fluid F to the outlet72via a plenum. In this example, the inlet70includes an inlet pipe90and an inlet plenum92. The outlet72likewise includes an outlet pipe94and an outlet plenum96. Each of the tubes74A-74F are directly coupled to the inlet plenum92at one end and the outlet plenum96at another end. Thus, each of the tubes74A-74F is configured to direct fluid F from the inlet plenum92to the outlet plenum96.

FIG. 4illustrates the thermal exchange assembly68ofFIG. 3without the housing62. As noted above, the thermal exchange assembly68is formed before it is overmolded with the housing62. In order to maintain the structural integrity of the thermal exchange assembly68before and during the overmolding process, the thermal exchange assembly68includes a plurality of die setting brackets98A-98J. In this example, each die setting bracket98A-98J connects the tubes74A-74F to one another. Here, there are a total of ten die setting brackets98A-98J. It should be understood that this disclosure extends to thermal exchange assemblies with a different number of die setting brackets.

In this example, there is a set of die setting brackets98A-98I that are spaced-apart from one another along the direction of the length L, and that extend in a direction substantially parallel to a direction of the width W. Notably, while the battery assembly54is not shown inFIG. 4, the directions of the length and width L, W are used herein to refer to the arrangement of the thermal exchange assembly68as it would be positioned in the battery assembly54. Each of the die setting brackets98A-98I are connected to each the tubes74A-74F, and are further connected to both the inlet and outlet sides76,80of each of the tubes74A-74F. Thus, these die setting brackets98A-98I are connected to each of the tubes74A-74F in two locations. The example ofFIG. 4also includes one die setting bracket98J extending in a direction substantially parallel to a direction of the length L of the battery assembly54, and is connected to each of the tubes74A-74F at a location adjacent the turning sections78of the tubes. It should be understood that there could be a different number of die setting brackets in other examples.

FIG. 5is a side view of a portion of the tube74A, and shows one example arrangement of the die setting brackets relative to the thermal exchange assembly68. In this example, the die setting brackets are provided in an alternating arrangement, such that adjacent die setting brackets project from opposite sides of the tubes.FIG. 5shows two adjacent die setting brackets98A,98B. In this example, the die setting bracket98A projects from a first side100of the tube74A and projects from a corresponding side of the remaining tubes74B-74F. The die setting bracket98B projects from a second side102of the tube74A, which is opposite the first side100, and also projects from a corresponding side of the remaining tubes74B-74F. In this example, the first side100is a bottom of the tube74A, and the second side102is a top of the tube74A. While only two die setting brackets98A,98B are shown inFIG. 5, it should be understood that the remaining die setting brackets98C-98I continue on in an alternating arrangement (e.g., die setting bracket98C projects from the first side100, and so on). The alternating die setting bracket arrangement is useful when overmolding the tubes74A-74F with the housing62. One example overmolding process will now be described.

FIG. 6is a flow chart representative of one example method104of forming the battery assembly54. The method104will be described with reference toFIGS. 6-8. In the method104, the thermal exchange assembly68, including the thermal exchange tubes74A-74F, is placed into a mold cavity at106.

FIG. 7illustrates a portion of a molding cavity108between first and second mold plates110,112, and further illustrates a portion of the thermal exchange assembly68in the molding cavity108.FIG. 7is a side view, and thus only the tube74A is visible. The die setting brackets98A,98B are in direct contact with one of the mold plates110,112. In particular, the die setting bracket98A is in direct contact with the second mold plate112, and the die setting bracket98B is in direct contact with the first mold plate110. In some embodiments, the first and second mold plates110,112have channels that act as locating features for receiving the die setting brackets98A,98B, and thereby assist in aligning the thermal exchange assembly68within the molding cavity108.

Because of the alternating arrangement of the die setting brackets98A,98B, the material that ultimately forms the housing62can flow relatively easily within the molding cavity108during the overmolding process. For example, at a location adjacent the die setting bracket98A, material can flow around the tube74A on the second side102, because there is no die setting bracket in that location. Likewise, adjacent the die setting bracket98B, material can flow around the tube74A adjacent the first side100.

With reference toFIG. 6, after the thermal exchange assembly68is placed in the molding cavity108, the thermal exchange assembly68is overmolded with the housing62, and in particular the tubes74A-74are overmolded with the housing62, at step114. In this example, the overmolding process (sometimes referred to as insert molding) includes a molding process wherein a material having a different chemical composition than the tubes74A-74F is injected into the molding cavity108, and bonds to the tubes74A-74F as it cools. In one particular example, the tubes74A-74F are formed of steel, aluminum, or iron or copper, and the material injected into the molding cavity is plastic or magnesium. The plastic or magnesium or aluminum material will ultimately take the shape of the molding cavity and form the housing62. This disclosure is not limited to these particular example materials, however.

The result of step114is illustrated inFIG. 8. As shown, the tube74A is completely surrounded by the housing62. Further, in this example, ends of the die setting brackets98A,98B are flush with first and second surfaces116,118of the housing62, which correspond to an underside and an interior of the housing62, respectively. As shown inFIG. 8, the housing62exhibits a height H, which is reduced relative to battery assemblies that do not have overmolded tubes. As such, the battery assembly54occupies less space in the vehicle than battery assemblies without overmolded tubes. Further, since the tubes74A-74F are overmolded with the housing62, there are fewer mechanical connections within the battery assembly54. Thus, the likelihood of leaks is significantly reduced. Further, the fluid F can be directed through the tubes74A-74F at an increased pressure, which in turn increases the efficiency of the thermal exchange assembly68.

FIG. 9illustrates another example thermal exchange assembly68′, which has an alternate tube and plenum arrangement. The thermal exchange assembly68′ can be incorporated into a battery assembly, such as that ofFIG. 2. In the example ofFIG. 9, fluid F is circulated within the battery assembly54in two different directions. For example, the thermal exchange assembly68′ has a plurality of tubes74A-74F arranged such that the tubes are spaced inward of one another, substantially as described above relative toFIGS. 3 and 4. Further, it should be understood that the tubes74A-74F are overmolded with the housing62, as in the prior embodiment.

The thermal exchange assembly68′ includes inlet and outlet plenums92′,96′ that are different than those described above. The arrangement of the tubes74A-74F relative to the plenums92′,96′ allows the fluid F to flow in two different directions.

In this example, there is a first set of tubes configured to direct fluid F from the inlet plenum92′ to the outlet plenum96′ in a first direction D1, which in this example is a counter-clockwise direction. The first set of tubes includes tubes74A,74C, and74E. Further, there is a second set of tubes configured to direct fluid F in a second direction D2opposite the first direction D1. In this example, the second direction D2is a clockwise direction. The second set of tubes includes tubes74B,74D, and74F. In this example, the first and second sets of tubes are alternating, such that the outermost tube74A is one of the first set of tubes, and the immediately inward tube74B is one of the second set of tubes, and so on.

The inlet and outlet plenums92′,96′ are larger in this example than in the embodiment ofFIGS. 3-4. In this example, the inlet plenum92′ includes a first section116and a second section118. The second section118is spaced-apart from the first section116in a direction of the length L. The outlet plenum96′ likewise includes a first section120aligned with the first section116in the direction of the length L, and a second section122aligned with the second section118in the direction of the length L. The first and second sections120,122of the outlet plenum96′ are spaced-apart from one another in the direction of the length L. Further, like in the previous embodiment, the inlet and outlet plenums are fluidly coupled to inlet and outlet pipes, respectively, but those pipes are not shown inFIG. 9for purposes of illustrating the remainder of the thermal exchange assembly68′.

With continued reference toFIG. 9, the first set of tubes are fluidly coupled to the first section116of the inlet plenum92′ and the first section120of the outlet plenum96′, and the second set of tubes are fluidly coupled to the second section118of the inlet plenum92′ and the second section122of the outlet plenum96′. For example, the tube74A is fluidly coupled to the first section116of the inlet plenum92′ and is configured to direct fluid F in the direction D1to the first section120of the outlet plenum96′. Further, the tube74B is fluidly coupled to the second section118of the inlet plenum92′, which is on a generally opposite side (relative to the width W) of the first section116of the inlet plenum92′. The tube74B directs fluid F from the second section118in the direction D2to the second section122of the outlet plenum96′.

The arrangement ofFIG. 9evenly distributes cooling between the sides of the battery array56. In the embodiment ofFIGS. 3 and 4, the side of the battery array56adjacent the inlet70may experience additional cooling, because the fluid F within the tubes adjacent the outlet72may be relatively warm. Accordingly, the arrangement ofFIG. 9may increase the efficiency of heat transfer. While one example plenum arrangement has been shown and described inFIG. 9, other plenum arrangements that direct fluid in opposite directions come within the scope of this disclosure.

FIG. 10illustrates another example thermal exchange assembly68″. In this example, the thermal exchange assembly68″ includes a plurality of tubes that are substantially the same size and shape, unlike the tubes in the examples ofFIGS. 2-4 and 9, which are different sizes. Providing the same size tubes may reduce manufacturing costs and increase ease of assembly.

With continued reference toFIG. 10, the thermal exchange assembly68″ includes tubes124A-124E that are laterally spaced-apart from one another, relative to the direction of the width W. For example, the tube124A includes an inlet side126fluidly coupled to an inlet plenum128, an outlet side130fluidly coupled to an outlet plenum132, and a turning section134configured to turn the fluid F and direct the fluid F from the inlet side126to the outlet side130. The inlet and outlet sides126,130of the tube124A span along substantially the entire length (e.g., in the direction L) of the battery assembly54. Each of the tubes124A-124E are arranged in substantially the same way as the tube124A.

Again, the tubes124A-124E are laterally spaced-apart from one another. In this example, the tube124A defines a first tube perimeter, and the tube124B is laterally spaced-apart from that first tube perimeter in a direction of the width W. Further, the tube124C is laterally spaced-apart from a second tube perimeter defined by the tube124B, as so on.

In this example, the inlet and outlet plenums128,132extend in the direction of the width W. The outlet plenum132, in this example, is spaced-apart from the inlet plenum128in the direction of the length L. As such, the inlet side126of the tubes124A-124E is shorter than the outlet side130of the tubes124A-124E. While one particular plenum arrangement is shown in this disclosure, it should be understood that the thermal exchange assembly68″ could include other plenum arrangements.

Positioning the tubes124A-124E as shown inFIG. 10increases the uniformity of cooling along the direction of the width W of the battery assembly54, which increases cooling efficiency. It should be understood that the tubes124A-124E are also overmolded with a housing of the battery assembly, as described relative to the previous embodiments.

FIG. 11illustrates another example battery assembly54from a bottom perspective. The battery assembly54ofFIG. 11includes another example thermal exchange assembly68′. In this example, the thermal exchange assembly68′ includes an inlet plenum92″, an outlet plenum96″, and a return plenum135provided on an opposite end of the battery assembly54relative to the inlet and outlet plenums92″,96″. The thermal exchange assembly68′″ includes a plurality of tubes, as shown inFIG. 12.

Referring toFIGS. 11 and 12, the thermal exchange assembly68′″ includes a plurality of inlet-side tubes136A-136F configured to direct fluid from the inlet plenum92″ to the return plenum135. The thermal exchange assembly68′″ further includes a plurality of outlet-side tubes138A-138F configured to direct fluid from the return plenum135to the outlet plenum96″. The tubes136A-136F,138A-138F are substantially straight tubes extending in a direction substantially parallel to a length L. The tubes136A-136F,138A-138F are all the same size and shape in this example.

Further, in this example, the tubes136A-136F,138A-138F are initially formed with closed ends140, as shown inFIG. 13. The tubes136A-136F,138A-138F are crimped at each end thereof to provide the closed ends140. Providing the tubes with closed ends140prevents unwanted material from entering the tubes during manufacturing, including during the overmolding process.

The battery assembly54ofFIG. 11is formed similarly to the previous embodiments, however the plenums92″,96″,135are formed after the tubes136A-136F,138A-138F are overmolded with the housing62at step114(FIG. 6). With reference to the method104ofFIG. 6, the plenums92″,96″,134are formed at step142by machining the plenums92″,96″,135into a bottom of the housing62. In one example, the plenums92″,96″,135are formed using a milling process. During the milling process, not only are the plenums92″,96″,135formed, but the closed ends140are removed from the tubes136A-136F,138A-138F, thereby opening the tubes and allowing fluid F to flow therein.

Machining the plenums92″,96″,135after the overmolding process leaves open cavities in the bottom of the housing62. Thus, at step144(FIG. 6), plenum caps146are provided to cover the plenums92″,96″,135by welding, for example. One example arrangement is shown in the cross-sectional view ofFIG. 14. InFIG. 14, there is a plenum cap146connected to a bottom of the housing62, which seals the inlet plenum92″. Thus, fluid F is permitted to flow into the inlet70, to the inlet plenum92″, and along the tube136A toward the return plenum135.

FIGS. 15-16illustrate the thermal exchange assembly68including a thermal transfer plate148. In this example, the thermal transfer plate148sits atop the tubes74A-74F, and is made of a thermally conductive material. Thus, the thermal transfer plate148distributes heat and facilitates heat transfer between the tubes74A-74F and the cells58. In this example, the tubes74A-74F and the thermal transfer plate148are overmolded with the housing62. As shown inFIG. 16, the thermal transfer plate148sits directly atop the die setting brackets (e.g.,98B) projecting from the top side of the tubes74A-74F. The cells58of the battery array56sit directly on the thermal transfer plate148in one example. The thermal transfer plate148may be particularly beneficial when the housing62is made of a material that has low thermal conductivity, such as when the housing62is made of plastic.

FIG. 17illustrates the thermal exchange assembly68with an electromagnetic compatibility (EMC) shield150. The EMC shield150is essentially a box formed by a plurality of walls projecting from the thermal transfer plate148. In this example, the EMC shield150is overmolded with the housing62together with the thermal transfer plate148and tubes74A-74F. The EMC shield150is made of the same material as the thermal transfer plate148in one example, or the EMC shield can be provided by other conductive material. The material of the EMC shield is configured to meet EMC regulations.

It should be understood that the above-discussed embodiments are combinable, except where such combination is not possible. For example, the thermal transfer plate148and EMC shield150could be incorporated into the embodiments ofFIGS. 9, 10, and 11. As an additional example, while not shown inFIGS. 10-12, these embodiments could include die setting brackets. Further, it should be understood that the method104applies to each of the disclosed embodiments, except where otherwise noted. For example, all of the embodiments disclosed herein include a thermal exchange assembly with one or more tubes overmolded with a housing of a battery assembly. Additionally, each of the disclosed assemblies could include tubes with crimped ends that are opened after overmolding, as described relative toFIG. 13.

It should be understood that references to the length and width directions (e.g., L, W) and terms such as “lateral” are used herein for purposes of explanation, and should not be considered otherwise limiting. Terms such as “generally,” “substantially,” and “about” are not intended to be boundaryless terms, and should be interpreted consistent with the way one skilled in the art would interpret those terms.