Abstract:
A battery module for receiving battery cells provides cooling through a cooling fluid. Chilled fluid travels first to the hottest part of the battery module and then continues to gradually less hot areas. As the chilled cooling fluid absorbs heat and travels to cooler parts of the battery module, the heat transfer between the fluid and the battery cells decreases because the temperature differential between the cells and cooling fluid decreases, providing a more even temperature distribution across the battery module. The cooling fluid may be contained in a conduit associated with one or more cooling plates. A plurality of slots provide a precise mechanical support for each battery cell, increasing the heat conduction from the cell to the battery module, protecting the battery module from vibration and decreasing contamination in case of thermal runaway or other damage to the cells.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims the benefit of 35 USC 119(e) to U.S. Provisional Application Ser. No. 61/631,455 filed 5 Jan. 2012 (5 Jan. 2012). 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to battery modules for battery cells. More particularly, the present invention relates to the thermal management of battery modules. 
       BACKGROUND OF THE INVENTION 
       [0003]    Batteries have been proposed as a clean, efficient and environmentally responsible power source for electric vehicles, and various other applications. They are also becoming more popular for large-scale energy storage, providing frequency regulation or auxiliary power to the power grid and allowing better use of intermittent power generation from sources like wind turbines and solar panels. 
         [0004]    Battery cells, and in particular, lithium ion cells, are known to generate heat when charging or discharging. Overheating or an exposure to high temperatures may undesirably affect the functioning and lifespan of a battery system. Thus battery systems typically employ some form of cooling system. 
         [0005]    Many systems use some form of air cooling, mainly due to convenience. These are shown, for instance, in U.S. published application 2003/0211384 published Nov. 13, 2003, U.S. published application 2006/0080986A1 published Apr. 20, 2006 and U.S. published application 2007/0102213 published May 10, 2007 incorporated herein by reference. An additional benefit of these cooling systems is that air is not electrically conducting and as such will not cause short circuits. However, air has a low thermal conductivity and a low heat capacity; thus air cooling systems exhibit inadequate efficiency for use with larger batteries. 
         [0006]    Another common setup is to include tubes or channels to conduct a cooling fluid between the individual cells in a battery module. Because aqueous fluids are most commonly used, and aqueous fluids are generally conductive, leaks in these systems can be very damaging to the battery system. To ensure fluid-tight joining of the parts and components and to minimize susceptibility to leakage, processes and equipment used to assemble this type of cooling system are highly automated, complex, and have costs for manufacture and maintenance. 
         [0007]    An additional concern is the temperature distribution throughout a cell or battery module. Cell temperature affects charging efficiency and capacity; lower capacity can lead to over-discharging, which will lower the operational lifespan of the cell and the battery as a whole. Batteries with greater temperature uniformity tend to operate more efficiently and have longer operating lives. 
         [0008]    A further difficulty with larger electric chemical battery cells is that different parts of the batteries themselves may have different localized temperatures. This is the case for a number of reasons including the physical size of the cells themselves, the poor thermal conductivity within the cells themselves, and the fact that some sections of the cells may generate more heat than other sections. In other words, specific parts of the cells may have different localized temperatures requiring different cooling to avoid undesirable effects. 
         [0009]    Therefore, there is a need in the art for a battery module which efficiently removes heat from the battery cells and produces a more uniform temperature distribution amongst the battery cells, while providing the necessary functionality with respect to containment and protection. 
       SUMMARY OF THE INVENTION 
       [0010]    It is an object of this invention to at least partially overcome some of the disadvantages of the prior art. Also, it is an object of at least one aspect of this invention to provide an improved type of a battery module and case therefor which contains at least one battery cell, and at least one conduit carrying a cooling fluid to cool the at least one cell. The conduit is in thermal contact with the battery cells to cool them. The conduit may be associated with a cooling plate and either contained therein, or integrally formed therewith, or may be in thermal contact with the cooling plate, but contained external thereof. 
         [0011]    Accordingly, in one aspect, the present invention provides a system for cooling a battery module having a plurality of individual battery cells, each cell having electrical terminals at an electrical connecting end, said system comprising: a plurality of substantially parallel thermally conductive slots, each of said slots extending generally in a lateral direction for holding said battery cells in an inserted position with the connecting ends aligned with the connecting end of each other battery cell in a longitudinal direction and at a first portion of the battery module; a cooling conduit extending along the longitudinal direction, said conduit having an inlet for receiving chilled coolant and an inlet portion substantially adjacent the inlet, said cooling conduit in thermal contact with said cells; wherein the inlet portion extends in the longitudinal direction across the plurality of slots and coincident with the first portion of the battery module so as to cool the connecting ends of each of the battery cells before cooling other portions of the battery cells. 
         [0012]    In a further aspect, the present invention provides a battery module comprising: a plurality of battery cells, each battery cell substantially rectangularly shaped with electrical terminals at a first connecting end, which is opposite a second opposed end; a cell support for holding said battery cells in an inserted position with the connecting ends of the cells aligned in a longitudinal direction and extending along a lateral direction; a cooling conduit having an inlet for receiving chilled coolant, said cooling conduit in thermal contact with said cells; wherein the cooling conduit has an inlet portion substantially adjacent the inlet and extending in the longitudinal direction proximate the connecting end of the cells to cool the connecting end of the battery cells before cooling other portions of the cells. 
         [0013]    In a still further aspect, the present invention provides a case for containing individual battery cells, each battery cell having electrical terminals at an electrical connecting end and opposed end opposite the connecting end, said case comprising: at least one cooling plate in thermal contact with a corresponding cooling conduit, said cooling conduit having an inlet portion near an inlet for receiving chilled cooling fluid; a cell support for receiving and supporting the battery cells in an inserted position with the connecting end of each battery cell aligned with the connecting end of each other battery cell and coincident with the first portion of the case; wherein the first portion of the case coincides with the inlet portion of the cooling conduit so as to cool the first portion of the case before cooling other portions of the case. 
         [0014]    In a further aspect, the present invention provides a method of managing heat generated by a battery module, said method comprising: orienting a plurality of battery cells in an inserted position with the connected end having the electrical terminals for the battery cell aligned with each other and coincident with a first portion of the battery module; and providing a chilled coolant initially to the first portion of the battery module before cooling other portions of the battery module. 
         [0015]    In order to provide a more uniform temperature distribution, chilled cooling fluid travels preferably first to the hottest area of the battery module. The hottest area will generally be where the terminals of the cells are located. In one aspect of the invention, the battery cells, when in the inserted position, are arranged such that the terminals are all near the first portion of the battery module and this coincides with the initial portion of the cooling conduit. The initial portion of the cooling conduit is the portion closest to the inlet for the cooling fluid and therefore, the cooling fluid is at its coldest. Heat transfer will occur at the greatest rate at the first portion because the fluid is at its coldest and also because the first portion of the battery module will be the hottest due to the orientation of the battery cells. A larger differential in temperature between the battery module and the cooling fluid would increase the heat transfer thereby providing increased cooling to the portion of the battery module requiring it the most. As the fluid moves along the path of the conduit towards the less hot areas of the battery module, the fluid becomes warmer from the heat absorbed. Also, the less hot portions of the module are at a lower temperature. Thus, the rate of heat transfer slows given that the temperature differential between the cooling fluid and the module is less. Thus, more heat is absorbed by the cooling fluid in the hotter areas and less heat is absorbed by the cooling fluid at the other areas, thereby leading to a more uniform temperature distribution in the battery module even in cases where the battery cells and/or the corresponding battery module is larger and/or has different temperatures. 
         [0016]    In one aspect, the present invention is used in applications where thermal management may be critical, such as large lithium ion battery cells, such as those used in electric vehicles. Similarly, large lithium battery cells are also used in grid energy storage. It is understood, however, that the present invention can be used in other applications where large battery cells may be needed. 
         [0017]    In the particular embodiment where the battery cells are used in electric vehicle applications, the present invention could share components of the vehicle&#39;s existing air conditioning system to cool the cooling fluid. For instance, the chilling fluid could be chilled by the air conditioning components of the vehicle prior to their introduction into the cooling conduit. Similarly, in grid energy storage applications, if other air conditioning units are used to cool the facility, or specific components within the facility, the same air conditioning components can be used to chill the cooling fluid. In other cases, separate cooling systems may be required. 
         [0018]    In addition to cooling of the battery cells, the case of the present invention also fulfills other functions. For instance, the cells are protected from vibration and are contained in the event of damage, such as from thermal runaway. In addition, having slots which correspond to the shape of the cells increase the conduction of heat from the cells to the cooling conduit. Also, having slots which complement the shape of the cells also provides a mechanical support for each cell. In addition, in the aspect of the invention where the cells are contained in slots which are then located in a case, there is added protection from potential leakage of the cooling fluid and in the event of damage to the cells. 
         [0019]    Further aspects of the invention will become apparent upon reading the following detailed description and drawings, which illustrate the invention and preferred embodiments of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]    In the drawings, which illustrate embodiments of the invention: 
           [0021]      FIG. 1  is a top view of one embodiment of the invention, displaying the conduit embedded in a cooling plate according to one embodiment of the present invention; 
           [0022]      FIG. 2  is a perspective view of a further embodiment of the invention; 
           [0023]      FIG. 3  is a perspective view of a cell having tapered edges according to one embodiment of the present invention; and 
           [0024]      FIG. 4  is a flow diagram showing one configuration whereby cooling fluid is cooled by a vehicle&#39;s air conditioner prior to entering the battery module case all of which are mobile. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0025]    Preferred embodiments of the invention and its advantages can be understood by referring to the present drawings. In the present drawings, like numerals are used for like and corresponding parts of the accompanying drawings. 
         [0026]    As illustrated in  FIG. 1 , in one embodiment of the present invention, one, and preferably a plurality of battery cells, shown generally by reference numeral  10 , are contained within a battery module, shown generally by reference numeral  130 . The battery module  130  preferably is formed of a battery module case  13 , as shown in  FIGS. 1 and 2 . In a preferred embodiment, the battery module case  13  is preferably in the shape of a rectangular prism, having two longer sides along a longitudinal direction L D  and two shorter sides along a lateral direction A D . The longer sides, in a preferred embodiment, are formed by cooling plates, as shown generally by reference numeral  16 , and the two shorter sides in a preferred embodiment are formed by the end plates,  14 . 
         [0027]    The cooling plates  16  are preferably composed of a heat-conducting material, preferably aluminum or ceramic. In a preferred embodiment, each cooling plate  16  contains a cooling conduit  15 . The cooling conduit  15  is shown in dashed lines in  FIGS. 1 and 2  illustrating that in this embodiment it is embedded within the cooling plates  16 . It is understood that the conduit  15  need not necessarily be contained within or associated with the cooling plate  16  provided that the cooling conduit  15  is otherwise in thermal contact with the cells  10  contained within the battery module  130 . In a preferred embodiment, the cooling conduit  15  is integrally formed within the cooling plates  16 . 
         [0028]    In a further preferred embodiment, the cooling conduit  15  is composed of a heat-conducting material, also preferably aluminum or ceramic. In one preferred embodiment, the conduit  15  is preferably a tube formed of a single piece of material, such that there are no seams or joints within the cooling plate  16  and the case  13  of the battery module  130 . Also, a seamless cooling conduit  15  encased within the cooling plate  16  would minimize the risk of fluid leak in the functional containment area  101  where the cells  10  are contained. The fluid, as shown generally by reference numeral  8 , flowing through the conduit  15  is preferably water or refrigerant having a relatively high heat capacity to be able to absorb heat generated by the cells  10 . 
         [0029]    Heat is generated as an undesirable byproduct when the cells  10  are charged or discharged. In a preferred embodiment, heat is drawn from the cells  10  to the cooling conduit  15 , which is in thermal contact with the cells  10  contained in the functional containment area  101  of the battery module  130 . In a further preferred embodiment, heat is drawn from the cells  10  to the cooling plate  16  through which the conduit  15  may be contained, and then removed from the battery module  130  by the cooling fluid  8  being expelled from the conduit  15  and replaced with new chilled coolant. It is understood that the coolant  8  may be recycled, or in some applications could be permanently discarded, such as in cases where water is used from a large body of water to cool the battery module  130 . Thus, heat is removed by flowing the cooling fluid  8  through the conduit  15 , and, in a preferred embodiment, through the cooling conduit  15  contained in the cooling plate  16  of the battery module case  13 . 
         [0030]    In a preferred embodiment, as illustrated in  FIG. 2 , the case  13  has two cooling plates  16  and  16 ′, each shown extending along the longitudinal direction L D  of the case  13  and each cooling plate having a conduit  15 ,  15 ′. Having a conduit  15 ,  15 ′ located on each cooling plate  16 ,  16 ′ of the battery module case  13  provides more uniform cooling to the cells  10 . In one embodiment, the conduit  15  extends through the end plate  14  and outside of the battery module case  13 , where it is in fluid communication with the analogous second conduit  15 ′ extending on the second plate  16 ′. The conduits  15 ,  15 ′ in a preferred embodiment, are substantially the same and thus only one side  16  is shown in perspective view in  FIG. 2  with the second conduit  15 ′ shown extending to the other side of the battery case  13 . In a preferred embodiment, each of the first conduit  15  and second conduit  15 ′ join with the other to form common inlet  17   c  from the fluid source, which in a preferred embodiment is a reservoir or air conditioner shown generally by reference numerals  42  and  43  in  FIG. 4 . It is understood that the precise fluid source for the chilled fluid  8  would be in the knowledge of a person skilled in the art and depend on this specific application. 
         [0031]    Each conduit  15  and  15 ′ also preferably joins with a common outlet, as shown generally by reference numeral  20   o.  In this way, each conduit  15 ,  15 ′ will have an inlet  17 , which may stem from a common inlet  17   c,  and an outlet  20 , which may stem to the common outlet  20   c.    
         [0032]    In a preferred embodiment, the cells  10  are oriented with the terminals  11  towards the top of the case  13 . As illustrated in  FIG. 3 , the cells  10  preferably have two terminals  11 , a positive terminal  11   p  and a negative terminal  11   n  for extracting electrical energy from the cell  10  and also for recharging the cell  10 . The terminals  11  are generally located at a connection end, as shown generally by reference numeral  30  of the cell  10 . The end  32  opposed to the connection end  30  may still generate heat, but generally will not generate as much heat as the connecting end  30 . 
         [0033]    As illustrated in  FIGS. 1 and 2 , the cells  10  are oriented in the functional containment area  101  in an inserted position with the connecting end  30  of the cells aligned with each other. Preferably, a cell support, shown generally by reference numeral  102  is used to support the cells  10  in the inserted postion. In this way, the connecting end  30  of each of the battery cells  10  is coincident with a first portion  131  of the battery module  130 . In the preferred embodiment illustrated in  FIGS. 1 and 2 , the first portion  131  corresponds to the upper portion of the battery module  130 . It is understood that the first portion  131  or upper portion of the battery module  130  is the portion coincident with the connecting ends  30  of the cells  10  and electrical terminals  11  and therefore the first or upper portion  131  could be the upper 50% of the battery module  130  or case  13 , and more preferably is the upper 25% or 20% of the battery module  130  or case  13 . 
         [0034]    As also illustrated in  FIG. 2 , the initial portion  150  of the conduit  15 , which is adjacent to the inlet  17  and receives the chilled coolant  8 , extends along the first portion  131  of the battery module  130 . In this way, the chilled coolant  8 , which is initially received in the conduit  15  from the inlet  17  and is at its coolest temperature travels from the inlet  17  along the initial portion  150  of the conduit  15  coincident with the first portion  131  of the battery module  130  where the cells  10  are arranged with the connecting ends  30  aligned with each other and generate the most heat. In a preferred embodiment, where the conduit  15  is contained within the cooling plate  16 , the inlet portion  150  of the conduit  15  is contained at the upper portion of the cooling plate  16 . The fluid  8  then warms as it travels across the inlet portion  150 , which extends along the longitudinal direction L D  of the battery module  130 . In this way, the maximum heat transfer occurs between the most chilled coolant  8  entering from the inlet  17  and flowing in the initial portion  150  of the conduit  15  coincident with the first portion  131  of the battery module  130  where the connecting ends  30  of the cells  10  are aligned and produce the most heat because the temperature differential is greatest between the coolant  8  and the first portion  131  of the battery module  130 . 
         [0035]    The chilled coolant  8 , will then warm as it flows in the conduit  15  in that it absorbs the heat from the cells  10 . The conduit  15 , in a preferred embodiment, loops back and forth along the longitudinal direction L D  of the battery module  130 , as shown in  FIG. 2 . In the preferred embodiment, when the conduit  15  is contained in the cooling plate  16 , the fluid gradually approaches the bottom portion of the cooling plate  16  where the opposed ends  32  of the cells  10  are contained in the battery module  130 . It is understood that the opposed ends  32  of the cells  10  will generate less heat than the connecting end  30 . As such, the second portion of the battery module  130 , as shown generally by reference numeral  132 , and in this preferred embodiment, corresponds to the bottom portion of the battery case  13 , will tend to be cooler than the first portion  131  of the battery module  130  or upper portion of the plate  16  and case  13  in this embodiment. 
         [0036]    As the second portion  132  of the battery module  130 , corresponding to the bottom of the case  13  in this preferred embodiment, will be cooler because the opposed ends  32  of the cells  10  do not generate as much heat, and because the cooling fluid  8  in the outlet portion  160  has now travelled along the length of the conduit  15  to reach the outlet portion, as shown generally by reference numeral  160 , less heat is transferred as compared to the first portion  131  at the top of the case  13  because the temperature differential between the fluid  8  and the second portion  132  of the module  130  is less. In this way, less heat will be transferred at the bottom portion of the case  13  corresponding to the second portion  132  of the module  130  as opposed to the first portion  131  of the battery module  130  corresponding to the upper portion of the case  13  in this embodiment. As less heat is transferred from the second or bottom portion  132  than the upper or first portion  131 , and as more heat is generated at the connecting end  30  than the opposed end  32  of the cells  10 , a more uniform temperature distribution is achieved. This provides a more efficient, longer-lasting battery module  130  and cells  10 . Accordingly, specific temperature differentials within the cells  10  are accommodated for by providing the initial inlet portion  150  of the conduit  15 , which is substantially adjacent to the inlet  17 , at the location in the battery module  130 , coincident with the connecting end  30  of the cells  10  and providing the outlet portion  160  of the conduit  15  at the location of the second portion  132  of the battery module  130  coincident with the opposed ends  32  of the cells. 
         [0037]    As shown in  FIG. 2 , the conduit  15  preferably loops at least twice, and preferably additional times, to create a serpentine path  170  along a plane which is perpendicular to the lateral direction A D . In the preferred embodiment, the serpentine path  170  is contained in the cooling plate  16  which defines the plane perpendicular to the lateral direction A D  and parallel to the longitudinal direction L D . The inlet portion  150  would form the beginning of the path  170  and the outlet portion  160  would form the end of the path  170 . It is understood that the second conduit  15 ′ in the second cooling plate  16 ′ would have a similar path  170 . 
         [0038]    In a preferred embodiment, the cell support  102  in the functional containment area  101  comprises a plurality of slots, as shown generally by reference numeral  110 . Each slot  110  may contain one or more battery cells  10 . In a preferred embodiment, each slots  110  contain one battery cell  10  each and supports or holds the cells  10  in the inserted position. 
         [0039]    More preferably, the slots  110  have an internal surface area, as shown generally by reference numeral  113 , which compliments the external surface area  120  of the cells  10 . In this way, the contact surface area between the internal surface  113  of the slots  110  and the external surface  120  of the cells  10  can be maximized. In a further preferred embodiment, the slots  110  have articulations, as shown generally by reference numeral  18 , which are complementary to the shape of the cells  10  and, in particular, the taper  12  of the cells  10 . In this way, a relatively precise mechanical support is also provided by each of the slots  110  for each of the cells  10 . This is particularly of benefit when the battery module  130  is mobile, such as in an automoble, and subject to vibrations and bumps. In a preferred embodiment, the articulations  18  form a serrated edge on each side of the battery module case  13 . In this way, the plurality of slots  110  can hold the battery cells  10  in an inserted position with the connecting end  30  of each battery cell  10  aligned with the connecting ends  30  of the other cells  10  and coincident with the first portion  131  of the battery module  130  corresponding to the upper portion of the plate  16  and case  13  in this embodiment. 
         [0040]    In a further preferred embodiment, the slots  110  extend in the lateral direction, shown generally by reference numeral A D . The cooling plates  16  are arranged in a plane substantially perpendicular to the lateral direction L D . The first cooling plate  16  is associated with a corresponding first end  111  of the slots  110  and the second cooling plate  16 ′ is associated with a corresponding second end  112  of the slots  110 , shown in  FIG. 1 . The cell support  102 , in a preferred embodiment, comprise the plurality of slots  110  to hold the substantially rectangularly shaped cells  10  with the connecting ends  30  aligned in the longitudinal direction L D  and extending in the lateral direction A D . The cooling plates  16 ,  16 ′ thus are substantially perpendicular to the lateral direction A D  in which the rectangularly shaped cells  10  extend. 
         [0041]    In a preferred embodiment, the slots  110  comprise cross members  19  which link the two sides  111 ,  112  of the slots  110  and also link the two cooling plates  16 ,  16 ′ of the case  13 . The cross members  19  preferably extend between each of the cells  10  to form the slots  110 . The cross members  19  preferably are made of a heat-conducting material, such as aluminum or ceramic, and, the slots  110  have interior surfaces  113  which are in good thermal contact with the cells  10  as indicated above. In this way, good thermal contact can be made between the exterior surface  120  of the cells  10 , the internal surface  113  of the slots  110 , the cross members  19 , the cooling plate  16 , and the fluid  8  in the conduit  15 . In this way, the battery module  130  comprises a system, as shown generally by reference numeral  100 , to cool the cells  10 , such that more heat is removed from the hotter areas of the cells  10  corresponding to the connecting ends  30 , and less heat is removed from the cooler areas of the cells  10 , corresponding to the opposed end  32  in order to provide a more uniform temperature distribution in the battery module  130 . 
         [0042]    The cells  10  used in the present invention, in one embodiment, are preferably thin and mostly rectangular in shape, as shown generally in  FIG. 3 . As indicated above, each side of the cells  10  preferably have a taper  12 . The shape of the taper  12  is complementary to the articulations  18  of the slots  110  in the battery module case  13 . In the preferred embodiment, as illustrated in  FIGS. 1 ,  2  and  3 , the terminals  11 , on the connecting end  30  of the cells  10  are preferably located on the same short narrow face of the cell  10 , and the cell  10 , is oriented in the slots  110  in the battery module case  13  with the terminals  11  at the top. In this way, the battery cells  10  are held in the inserted position with the connecting end  30  aligned with each of the battery cells  10  and coincident with the first portion  131  of the battery module  130  which, in this embodiment, corresponds to the upper portion of the battery case  13 . The cells  10  are preferably oriented in an alternating fashion, such that, rather than all of the positive terminals  11   p  being on the left side of the slots  110  and all of the negative terminals  11   n  being on the right side of the slots  110 , for example, the line of terminals  11  along one edge of the slots  110  would alternate positive  11   p,  negative  11   n,  positive  11   p , negative  11   n,  and so forth. The battery cells  10  are preferably lithium ion based battery cells  10 . 
         [0043]    It is understood that the battery cells  10  may be of any type, but would typically be of a type which generate considerable heat. For instance, the battery cells  10  may be preferably lithium ion polymer cells, but other types of battery cells which generate heat and/or have a low thermal conductivity could be particularly useful with the cooling system  100  of the present invention. The battery module  130  preferably has a total capacity in excess of 1 MWh. Furthermore, the present invention is not limited by any particular application, but could be used in any type of application where heat generation and heat transfer is challenging, for example in large batteries like those used in electrical vehicles or grid energy management. 
         [0044]    In a preferred embodiment, where the system  10  is contained in a hybrid electric or electric vehicle (not shown), the cooling fluid can be water or any other type of aqueous fluid. In a second preferred embodiment, the vehicle may contain an air conditioning unit, as shown generally by reference numeral  43  in  FIG. 4 , and the same refrigerant used by the vehicle&#39;s air conditioner  43  to cool air can also be used as the cooling fluid  8  in the cooling system  100  of the battery module  130 . As also illustrated in  FIG. 4 , the refrigerant or cooling fluid  8  may travel from a reservoir  42  to the air conditioning unit  43 . There, in the air conditioning unit  43 , it may travel through the various components of the air conditioning unit  43 , such as the filter, compressor, etc. and it is chilled or cooled. However, rather than entering the evaporator and absorbing heat from the air in the vehicle, the chilled coolant fluid  8  exits the air conditioning unit  43  and travels to the battery module  130  where the chilled fluid  8  enters through the common inlet  17   c  to the inlets  17 ,  17 ′ of the conduits  15 ,  15 ′ to cool the cooling plates  16  and the cells  10  in the battery module  130 . In this embodiment, where the battery module  130  is in a vehicle, it is understood that the cooling system  100  including the module  130 , the reservoir  42  and the air conditioning unit  43  are all mobile. 
         [0045]    In the preferred embodiment where the conduits  15 ,  15 ′ are contained in the cooling plates  16 ,  16 ′, the cooling plates  16 ,  16 ′ will cool the cells  10  held in the slots  110  in the inserted position. The chilled coolant  8  will initially pass through the inlet portions  150  of the cooling conduits  15 ,  15 ′ to cool the warmer first portion  131  of the battery module  130  corresponding to the upper portion of the case  13  in the present embodiment. The warmed refrigerant  8  will pass through the cooler second portion  132  of the battery module  130 , which is adjacent the outlet  20  and also corresponds to the second portion  132  of the battery module  130  holding the opposed ends  32  which generates less heat. In this way, more uniform temperature distribution in the battery module  130  is achieved. The warmed coolant  8  will then exit the battery module  130  through the common outlet  20   c  to return to the reservoir  42 . 
         [0046]    To the extent that a patentee may act as its own lexicographer under applicable law, it is hereby further directed that all words appearing in the claims section, except for the above defined words, shall take on their ordinary, plain and accustomed meanings (as generally evidenced, inter alia, by dictionaries and/or technical lexicons), and shall not be considered to be specially defined in this specification. Notwithstanding this limitation on the inference of “special definitions,” the specification may be used to evidence the appropriate, ordinary, plain and accustomed meanings (as generally evidenced, inter alia, by dictionaries and/or technical lexicons), in the situation where a word or term used in the claims has more than one pre-established meaning and the specification is helpful in choosing between the alternatives. 
         [0047]    It will be understood that, although various features of the invention have been described with respect to one or another of the embodiments of the invention, the various features and embodiments of the invention may be combined or used in conjunction with other features and embodiments of the invention as described and illustrated herein. 
         [0048]    Although this disclosure has described and illustrated certain preferred embodiments of the invention, it is to be understood that the invention is not restricted to these particular embodiments. Rather, the invention includes all embodiments, which are functional, electrical or mechanical equivalents of the specific embodiments and features that have been described and illustrated herein.