Abstract:
A battery pack according to an exemplary aspect of the present disclosure includes, among other things, an electronics module and an electronics umbrella positioned to channel moisture away from the electronics module.

Description:
TECHNICAL FIELD 
       [0001]    This disclosure relates to a battery pack for an electrified vehicle. The battery pack includes an electronics umbrella configured to channel moisture away from one or more electronics modules housed inside the battery pack. 
       BACKGROUND 
       [0002]    The desire to reduce automotive fuel consumption and emissions is well documented. Therefore, vehicles are being developed that reduce or completely eliminate reliance on internal combustion engines. Electrified vehicles are one type of vehicle currently being developed for this purpose. In general, electrified vehicles differ from conventional motor vehicles because they are selectively driven by one or more battery powered electric machines. Conventional motor vehicles, by contrast, rely exclusively on the internal combustion engine to propel the vehicle. 
         [0003]    A high voltage battery pack typically powers the electric machines and other electrical loads of the electrified vehicle. The battery pack includes a plurality of interconnected battery cells that store energy for powering these electrical loads. Numerous electronics modules are also housed inside the battery pack. 
         [0004]    Moisture can accumulate inside the battery pack. Some internal components of the battery pack may therefore benefit from protection against moisture intrusion. 
       SUMMARY 
       [0005]    A battery pack according to an exemplary aspect of the present disclosure includes, among other things, an electronics module and an electronics umbrella positioned to channel moisture away from the electronics module. 
         [0006]    In a further non-limiting embodiment of the foregoing battery pack, the electronics module is a battery electronic control module. 
         [0007]    In a further non-limiting embodiment of either of the foregoing battery packs, the electronics umbrella includes a base and a ramp extending from the base. 
         [0008]    In a further non-limiting embodiment of any of the foregoing battery packs, the ramp is angled at a decline relative to the base. 
         [0009]    In a further non-limiting embodiment of any of the foregoing battery packs, an enclosure houses the electronics module, the enclosure including a tray and a cover. 
         [0010]    In a further non-limiting embodiment of any of the foregoing battery packs, the electronics module includes a connector cavity facing toward the cover. 
         [0011]    In a further non-limiting embodiment of any of the foregoing battery packs, the electronics umbrella at least partially covers the connector cavity of the electronics module. 
         [0012]    In a further non-limiting embodiment of any of the foregoing battery packs, a drain hole extends through the electronics umbrella. 
         [0013]    In a further non-limiting embodiment of any of the foregoing battery packs, insulation is attached to the electronics umbrella. 
         [0014]    In a further non-limiting embodiment of any of the foregoing battery packs, the insulation is attached to an inner surface of the electronics umbrella. 
         [0015]    In a further non-limiting embodiment of any of the foregoing battery packs, the insulation is sandwiched between an enclosure wall and the electronics umbrella. 
         [0016]    In a further non-limiting embodiment of any of the foregoing battery packs, the electronics umbrella is mounted to a wall of an enclosure that houses the electronics module. 
         [0017]    A battery pack according to another exemplary aspect of the present disclosure includes, among other things, an enclosure, a battery assembly housed inside the enclosure, an electronics module mounted adjacent to the battery assembly and an electronics umbrella mounted to a wall of the enclosure. The enclosure is comprised of a first material having a first thermal conductivity and the electronics umbrella comprised of a second material having a second thermal conductivity that is less than the first thermal conductivity. 
         [0018]    In a further non-limiting embodiment of the foregoing battery pack, the first material is a metal and the second material is a plastic. 
         [0019]    In a further non-limiting embodiment of either of the foregoing battery packs, a stud protrudes from the wall, and the electronics umbrella is secured to the stud with a fastening device. 
         [0020]    In a further non-limiting embodiment of any of the foregoing battery packs, the electronics umbrella includes a ramp configured to channel moisture away from the electronics module. 
         [0021]    In a further non-limiting embodiment of any of the foregoing battery packs, the ramp extends at an angle relative to a base of the electronics umbrella. 
         [0022]    In a further non-limiting embodiment of any of the foregoing battery packs, the electronics umbrella at least partially hovers over the electronics module and a second electronics module. 
         [0023]    In a further non-limiting embodiment of any of the foregoing battery packs, the electronics module is mounted to the enclosure by a mounting flange. 
         [0024]    A method according to another exemplary aspect of the present disclosure includes, among other things, positioning an electronics umbrella to at least partially extend above an electronics module housed inside a battery pack and communicating moisture that accumulates inside the battery pack along a surface of the electronics umbrella to a location remote from the electronics module. 
         [0025]    The embodiments, examples and alternatives of the preceding paragraphs, the claims, or the following description and drawings, including any of their various aspects or respective individual features, may be taken independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments, unless such features are incompatible. 
         [0026]    The various features and advantages of this disclosure will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0027]      FIG. 1  schematically illustrates a powertrain of an electrified vehicle. 
           [0028]      FIG. 2  illustrates a battery pack of an electrified vehicle. 
           [0029]      FIG. 3  illustrates portions of a battery pack. 
           [0030]      FIG. 4  is a cross-sectional view through section A-A of  FIG. 3  and illustrates a right hand orientation of an electronics umbrella. 
           [0031]      FIG. 5  illustrates a left hand orientation of an electronics umbrella. 
           [0032]      FIG. 6  illustrates yet another electronics umbrella. 
           [0033]      FIG. 7  illustrates an exemplary mounting configuration of an electronics umbrella. 
           [0034]      FIGS. 8A and 8B  illustrate additional exemplary electronics umbrellas. 
       
    
    
     DETAILED DESCRIPTION 
       [0035]    This disclosure details a battery pack of an electrified vehicle. The battery pack includes an electronics umbrella for preventing moisture, such as condensation, from infiltrating an electronics module housed inside the battery pack. In some embodiments, the electronics umbrella is arranged to channel moisture around and away from the electronics module. In other embodiments, the electronics module is comprised of a material having a thermal conductivity that is less than the thermal conductivity of the structure the electronics umbrella is mounted to. In this way, moisture accumulates on the structure before it accumulates on the electronics umbrella. These and other features are discussed in greater detail in the following paragraphs of this detailed description. 
         [0036]      FIG. 1  schematically illustrates a powertrain  10  for an electrified vehicle  12 . Although depicted as a hybrid electric vehicle (HEV), it should be understood that the concepts described herein are not limited to HEV&#39;s and could extend to other electrified vehicles, including, but not limited to, plug-in hybrid electric vehicles (PHEV&#39;s), battery electric vehicles (BEV&#39;s) and fuel cell vehicles. 
         [0037]    In one non-limiting embodiment, the powertrain  10  is 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 engine  14  and a generator  18  (i.e., a first electric machine). The second drive system includes at least a motor  22  (i.e., a second electric machine), the generator  18 , and a battery pack  24 . In this example, the second drive system is considered an electric drive system of the powertrain  10 . The first and second drive systems generate torque to drive one or more sets of vehicle drive wheels  28  of the electrified vehicle  12 . Although a power-split configuration is depicted in  FIG. 1 , this disclosure extends to any hybrid or electric vehicle including full hybrids, parallel hybrids, series hybrids, mild hybrids or micro hybrids. 
         [0038]    The engine  14 , which in one embodiment is an internal combustion engine, and the generator  18  may be connected through a power transfer unit  30 , 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 engine  14  to the generator  18 . In one non-limiting embodiment, the power transfer unit  30  is a planetary gear set that includes a ring gear  32 , a sun gear  34 , and a carrier assembly  36 . 
         [0039]    The generator  18  can be driven by the engine  14  through the power transfer unit  30  to convert kinetic energy to electrical energy. The generator  18  can alternatively function as a motor to convert electrical energy into kinetic energy, thereby outputting torque to a shaft  38  connected to the power transfer unit  30 . Because the generator  18  is operatively connected to the engine  14 , the speed of the engine  14  can be controlled by the generator  18 . 
         [0040]    The ring gear  32  of the power transfer unit  30  may be connected to a shaft  40 , which is connected to vehicle drive wheels  28  through a second power transfer unit  44 . The second power transfer unit  44  may include a gear set having a plurality of gears  46 . Other power transfer units may also be suitable. The gears  46  transfer torque from the engine  14  to a differential  48  to ultimately provide traction to the vehicle drive wheels  28 . The differential  48  may include a plurality of gears that enable the transfer of torque to the vehicle drive wheels  28 . In one embodiment, the second power transfer unit  44  is mechanically coupled to an axle  50  through the differential  48  to distribute torque to the vehicle drive wheels  28 . 
         [0041]    The motor  22  can also be employed to drive the vehicle drive wheels  28  by outputting torque to a shaft  52  that is also connected to the second power transfer unit  44 . In one embodiment, the motor  22  and the generator  18  cooperate as part of a regenerative braking system in which both the motor  22  and the generator  18  can be employed as motors to output torque. For example, the motor  22  and the generator  18  can each output electrical power to the battery pack  24 . 
         [0042]    The battery pack  24  is an exemplary electrified vehicle battery. The battery pack  24  may be a high voltage traction battery pack that includes a plurality of battery assemblies  25  (i.e., battery arrays or groupings of battery cells) capable of outputting electrical power to operate the motor  22 , the generator  18  and/or other electrical loads of the electrified vehicle  12 . Other types of energy storage devices and/or output devices could also be used to electrically power the electrified vehicle  12 . 
         [0043]    In one non-limiting embodiment, the electrified vehicle  12  has two basic operating modes. The electrified vehicle  12  may operate in an Electric Vehicle (EV) mode where the motor  22  is used (generally without assistance from the engine  14 ) for vehicle propulsion, thereby depleting the battery pack  24  state 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 vehicle  12 . During EV mode, the state of charge of the battery pack  24  may increase in some circumstances, for example due to a period of regenerative braking. The engine  14  is 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. 
         [0044]    The electrified vehicle  12  may additionally operate in a Hybrid (HEV) mode in which the engine  14  and the motor  22  are both used for vehicle propulsion. The HEV mode is an example of a charge sustaining mode of operation for the electrified vehicle  12 . During the HEV mode, the electrified vehicle  12  may reduce the motor  22  propulsion usage in order to maintain the state of charge of the battery pack  24  at a constant or approximately constant level by increasing the engine  14  propulsion. The electrified vehicle  12  may be operated in other operating modes in addition to the EV and HEV modes within the scope of this disclosure. 
         [0045]      FIG. 2  schematically illustrates a battery pack  24  that can be employed within an electrified vehicle. For example, the battery pack  24  could be part of the electrified vehicle  12  of  FIG. 1 . The battery pack  24  includes a plurality of battery cells  56  that store electrical power for powering various electrical loads of the electrified vehicle  12 . Although a specific number of battery cells  56  are depicted in  FIG. 2 , the battery pack  24  could employ a greater or fewer number of battery cells within the scope of this disclosure. In other words, this disclosure is not limited to the specific configuration shown in  FIG. 2 . 
         [0046]    The battery cells  56  are stacked side-by-side along a longitudinal axis A to construct groupings of battery cells  56 , sometimes referred to as cell stacks. The battery pack  24  can include one or more separate groupings of battery cells  56 . 
         [0047]    In one non-limiting embodiment, the battery cells  56  are prismatic, lithium-ion cells. However, battery cells having other geometries (cylindrical, pouch, etc.), other chemistries (nickel-metal hydride, lead-acid, etc.), or both, could alternatively be utilized within the scope of this disclosure. 
         [0048]    Spacers  54 , which can alternatively be referred to as separators or dividers, are optionally positioned between adjacent battery cells  56  of each grouping of battery cells  56 . The spacers  54  are made of thermally resistant and electrically isolating plastics and/or foams. The battery cells  56 , along with the spacers  54  and any other support structures (e.g., rails, walls, plates, etc.), may be collectively referred to as a battery assembly  25 . Two battery assemblies  25  are shown in  FIG. 2 ; however, the battery pack  24  could include a greater or fewer number of battery assemblies within the scope of this disclosure. 
         [0049]    An enclosure  60  generally surrounds each battery assembly  25  of the battery pack  24 . The enclosure  60  includes a plurality of walls  62 . The plurality of walls  62  together establish the enclosure  60 , which houses the various hardware and electronics of the battery pack  24 , including but not limited to, the battery assemblies  25  and at least one electronics module  58 . In one non-limiting embodiment, the electronics module  58  is a battery electronic control module (BECM). The electronics module  58  includes one or more connector cavities  72  for connecting various electrical components within the battery pack  24 . 
         [0050]    The walls  62  of the enclosure  60  could be part of either a tray  64  or a cover  66 , in another non-limiting embodiment. The cover  66  is shown in phantom in  FIG. 2  to better illustrate the interior components of the battery pack  24 . The cover  66  is attachable to the tray  64  to house the battery assemblies  25  and the electronics module  58 . 
         [0051]    Referring now to  FIGS. 3 and 4 , the electronics module  58  is mounted inside the enclosure  60  via a mounting flange  70 . The mounting flange  70  is secured to one of the walls  62 , which in the illustrated example is a bottom wall of the tray  64 . The electronics module  58  is mounted upright such that the connector cavities  72  are pointed upwardly toward the cover  66  of the enclosure  60 . In this upright pointed position, the connector cavities  72  of the electronics module  58  may be susceptible to moisture intrusion. An electronics umbrella  68  is therefore positioned inside the battery pack  24 . The electronics umbrella  68  is a hood-like structure arranged to cover the electronics module  58 . The electronics umbrella  68  channels moisture, such as condensation, away from the electronics module  58  to substantially prevent the moisture M from entering into the connector cavities  72 . 
         [0052]    The exemplary electronics umbrella  68  includes a base  74  and a ramp  76  that extends from the base  74 . The size, shape and geometry of the electronics umbrella  68 , including the size, shape and geometry of each of the base  74  and ramp  76 , is not intended to limit this disclosure in any way. In one non-limiting embodiment, the ramp  76  extends at an angle α relative to the base  74 . The ramp  76  extends to a position in which it hovers above the electronics module  58 . The ramp  76  may be declined in a direction that extends from the cover  66  toward the tray  64 . In this way, the ramp  76  aids in communicating moisture around and away from the electronics module  58 . For example, moisture M that accumulates inside the enclosure  60  may drop onto the ramp  76 . As the moisture M accumulates, it is channeled down the ramp  76 , toward the base  74 , and away from the electronics module  68 . The moisture M may be channeled toward the bottom of the enclosure  60 , for example. The ramp  76  may include a drain hole  78  adapted to permit moisture M to pass through the ramp  76  after it has been channeled far enough away from electronics module  58 . In one non-limiting embodiment, the drain hole  78  is positioned near the interface between the ramp  76  and the base  74 . The drain hole  78 , however, could be positioned at other locations of the electronics umbrella  68 . 
         [0053]      FIGS. 3 and 4  depict a right hand orientation of the electronics umbrella  68 . A left hand orientation of the electronics umbrella  68  may also be utilized to prevent moisture from entering the connector cavities  72  of the electronics module  58  (see, for example,  FIG. 5 ). Other configurations of the electronics umbrella  68  are also contemplated as within the scope of this disclosure. In yet another non-limiting embodiment, the electronics umbrella  68  is arranged to cover a plurality of electronics modules  58  (see, for example,  FIG. 6 ). In addition, although a single electronics umbrella  68  is depicted in the schematics accompanying this disclosure, the battery pack  24  could be equipped with multiple electronics umbrellas  68 . 
         [0054]    The electronics umbrella  68  is mounted to at least one of the walls  62  of the enclosure  60 . In this embodiment, the wall  62  is a sidewall of the enclosure  60 , and could be a sidewall of the tray  64 . However, it should be understood that the electronics umbrella  68  could be mounted to any portion of the enclosure  60 , including any wall  62  or any portion of the tray  64  or the cover  66 . 
         [0055]    In one non-limiting embodiment, the electronics umbrella  68  is a plastic structure and the walls  62  of the enclosure  60  are metallic structures. In another non-limiting embodiment, the electronics umbrella  68  is made of a material having a first thermal conductivity and the walls  62  of the enclosure  60  are made of another material having a second thermal conductivity. The first thermal conductivity may be a lower thermal conductivity than the second thermal conductivity to ensure that the moisture M (e.g., condensation) accumulates on the enclosure  60  prior to the electronics umbrella  68 . 
         [0056]    A non-limiting mounting configuration of the electronics umbrella  68  is illustrated in  FIG. 7 . One or more studs  80  protrude from the wall  62  of the enclosure  60 . The stud  80  extends through a slot  82  formed in the base  74  of the electronics umbrella  68 . The electronics umbrella  68  is secured to the wall  62  using a fastening device  84 , such as a nut. In another non-limiting embodiment, the electronics umbrella  68  is glued to one of the walls  62  of the enclosure  60 . Additional attachment mechanisms are also contemplated within the scope of this disclosure. Moreover, the electronics umbrella  68  could be mounted to the enclosure  60  or any other neighboring structure within the enclosure  60 . 
         [0057]    Referring to  FIGS. 8A and 8B , insulation  86  can be optionally used in conjunction with the electronics umbrella  68 . The insulation  86  reduces the amount of heat transfer that is effectuated between the wall  62  of the enclosure  60  and the electronics umbrella  68 . In a first non-limiting embodiment, the insulation  86  is attached to an inner surface  88  of the electronics umbrella  68  (see  FIG. 8A ). In a second non-limiting embodiment, the insulation  86  is sandwiched between the base  74  of electronics umbrella  68  and the wall  62  the electronics umbrella  68  is mounted to (see  FIG. 8B ). However, the insulation  86  could be positioned at any location that has an influence on the amount of heat transfer permitted to occur between the electronics umbrella  68  and the enclosure  60 . 
         [0058]    Although the different non-limiting embodiments are illustrated as having specific components or steps, the embodiments of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from any of the non-limiting embodiments in combination with features or components from any of the other non-limiting embodiments. 
         [0059]    It should be understood that like reference numerals identify corresponding or similar elements throughout the several drawings. It should be understood that although a particular component arrangement is disclosed and illustrated in these exemplary embodiments, other arrangements could also benefit from the teachings of this disclosure. 
         [0060]    The foregoing description shall be interpreted as illustrative and not in any limiting sense. A worker of ordinary skill in the art would understand that certain modifications could come within the scope of this disclosure. For these reasons, the following claims should be studied to determine the true scope and content of this disclosure.