Abstract:
A battery pack includes battery cells in a plurality of neighboring rows arranged in a first direction, each row of the neighboring rows including a plurality of the battery cells arranged in a second direction, a holder between the neighboring rows of the battery cells, the holder having a first surface contacting a side surface of each of the battery cells forming a first row among the neighboring rows and a second surface contacting a side surface of each of the battery cells forming a second row among the neighboring rows, and a temperature device that measures a temperature of the battery cells. The holder includes a receiving groove extending inwardly from at least one of the first surface and the second surface of the holder to receive the temperature device, and a cooling hole that passes through the holder to enable a fluid to enter and exit the holder.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    Korean Patent Application No. 10-2013-0128643, filed on Oct. 28, 2013, in the Korean Intellectual Property Office, and entitled: “Battery Pack,” is incorporated by reference herein in its entirety. 
       BACKGROUND 
       [0002]    1. Field 
         [0003]    One or more embodiments relate to a battery pack. 
         [0004]    2. Description of the Related Art 
         [0005]    Secondary batteries are rechargeable unlike primary batteries that are not rechargeable. The secondary batteries are widely used not only in small high-tech electronic devices, such as mobile phones, personal digital assistants (PDAs), and notebook computers, but also in energy storage systems. 
       SUMMARY 
       [0006]    Embodiments are directed to a battery pack including battery cells in a plurality of neighboring rows arranged in a first direction, each row of the neighboring rows including a plurality of the battery cells arranged in a second direction, a holder between the neighboring rows of the battery cells, the holder having a first surface contacting a side surface of each of the battery cells forming a first row among the neighboring rows and a second surface contacting a side surface of each of the battery cells forming a second row among the neighboring rows, and a temperature device that measures a temperature of the battery cells. The holder includes a receiving groove extending inwardly from at least one of the first surface and the second surface of the holder to receive the temperature device, and a cooling hole that passes through the holder to enable a fluid to enter and exit the holder. 
         [0007]    A depth of the receiving groove from the first surface or the second surface of the holder may be equal to or less than a thickness of the temperature device. 
         [0008]    The receiving groove may be a first receiving groove. The temperature device may be connected to a wire that extends toward an outside. The holder may further include a second receiving groove that is coupled to the first receiving groove and receives the wire. 
         [0009]    The first row and the second row may each include outer battery cells at respective outer sides of the first row and the second row and one or more inner battery cells located inwardly from the outer battery cells in the first row and the second row. The temperature device may contact the side surface of an inner battery cell among the one or more inner battery cells in the first row or the second row. 
         [0010]    The battery cells may be cylindrical battery cells each extending in a third direction orthogonal to the first direction and the second direction. The holder may have a height in the third direction greater than or equal to a height of the battery cells. 
         [0011]    The cooling hole may pass through the holder in the third direction. 
         [0012]    The first surface and the second surface of the holder may include recesses, each conforming to the side surface of one of the battery cells. 
         [0013]    The holder may further include stoppers that contact at least one of top surfaces and bottom surfaces of the battery cells of the first row and the second row. 
         [0014]    The battery pack may further include a bus bar that electrically connects the battery cells, the bus bar covering the battery cells and the holder and including a hole formed at a position corresponding to the cooling hole. 
         [0015]    The fluid that is enabled by the cooling hole to enter and exit the holder may be air. 
         [0016]    The battery pack may further include a pair of end holders at respective ends of the battery pack in the first direction, the pair of end holders and the holder being coupled by a coupling member that passes in the first direction through the pair of end holders and the holder. 
         [0017]    The holder may include a first edge portion and a second edge portion at respective ends of the holder in the second direction and a partition portion that couples the first edge portion and the second edge portion, the partition portion including the receiving groove and the cooling hole. 
         [0018]    Each of the first edge portion and the second edge portion may protrude in the first direction from the partition portion toward the battery cells forming the first row and toward the battery cells forming the second row. 
         [0019]    Each of the first edge portion and second edge portion may protrude in the first direction toward the battery cells forming the first row by a distance corresponding to a radius of the battery cells of the first row and protrudes in the first direction toward the battery cells forming the second row by a distance corresponding to a radius of the battery cells of the second row. 
         [0020]    The coupling member may include a plurality of coupling members. Respective ones of the coupling members may pass through the first edge portion or the second edge portion of the holder 
         [0021]    The battery cells may be cylindrical. The partition portion may include recesses conforming to the side surfaces of the battery cells of the first row and the second row. The partition portion may include a relatively thick portion and a relatively thin portion, the relatively thin portion being formed by the recesses. 
         [0022]    The cooling hole may be formed at the relatively thick portion. 
         [0023]    The neighboring rows of the battery cells may include include three or more rows of the battery cells. The holder may include a plurality of adjacent holders, each of the holders being between the neighboring rows of the battery cells. The first edge portion of the adjacent holders may contact each other and the second edge portion of the adjacent holders may contact each other. 
         [0024]    The relatively thick portion of each of the adjacent holders may contact each other. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]    Features will become apparent to those of skill in the art by describing in detail exemplary embodiments with reference to the attached drawings in which: 
           [0026]      FIG. 1  illustrates a schematic perspective view of a battery pack according to an embodiment; 
           [0027]      FIG. 2  illustrates a detailed perspective view depicting a holder and a temperature unit illustrated in  FIG. 1 ; 
           [0028]      FIG. 3  illustrates a front view of the holder depicted in  FIG. 2 ; 
           [0029]      FIG. 4  illustrates a perspective view taken along line IV-IV in  FIG. 2 ; and 
           [0030]      FIG. 5  illustrates a detailed perspective view depicting end holders according to an embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0031]    Example embodiments will now be described more fully hereinafter with reference to the accompanying drawings; however, they may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey exemplary implementations to those skilled in the art. 
         [0032]    In the drawing figures, the dimensions of layers and regions may be exaggerated for clarity of illustration. Like reference numerals refer to like elements throughout. 
         [0033]      FIG. 1  illustrates a schematic perspective view of a battery pack according to an embodiment. 
         [0034]    Referring to  FIG. 1 , the battery pack may include battery cells  10  forming a plurality of rows, a holder  20  interposed between neighboring rows of battery cells  10 , a temperature unit  30  that obtains temperature information of the battery cell  10 , a pair of end holders  41  and  42  disposed at an outermost portion of the battery cells  10 , coupling members  51  and  52 , and first and second bus bars  61  and  62  that electrically couple the battery cells  10 . 
         [0035]    The battery cells  10  may be cylindrical. For example, as illustrated in  FIG. 1 , the battery cells  10  may have a cylindrical shape that extends in a third direction (z direction in  FIG. 1 ) that is perpendicular to first and second directions. The holder may have a height in the z direction that is greater than or equal to a height of the battery cells  10  in the z direction. 
         [0036]    The battery cells  10  may be rechargeable battery cells. For example, the battery cells  10  may be nickel-cadmium (Ni—Cd) battery cells, nickel-hydrogen (Ni—H) battery cells, or lithium (Li) ion battery cells. A lithium ion battery cell has an operation voltage that is three times higher than the operation voltage of a nickel-cadmium battery cell or a nickel-hydrogen battery cell. Accordingly, the lithium ion battery may be widely used as a power supply for portable electronic equipment. The lithium ion battery has a high energy density per unit weight, and may be used for various purposes. 
         [0037]    The battery cells  10  may form a plurality of rows. For example, four battery cells  10  may be arranged in the first direction (y direction in  FIG. 1 ) to form a row of battery cells  10 . When the battery cells  10  are disposed in this manner, the battery cells  10  may form a plurality of rows R 1 , R 2 , . . . , Rm. The rows R 1 , R 2 , . . . , Rm may be disposed in parallel to each other in the second direction (x direction in  FIG. 1 ) across the first direction. 
         [0038]    Although the present embodiment illustrates a case where four battery cells  10  form one row, in other implementations, two or more battery cells  10  may form one row. 
         [0039]    In this specification, for the convenience of description, a set of battery cells  10  forming one of row of adjacent battery cells is designated as a first row R 1 , and a set of battery cells  10  forming an adjacent one of the rows is designated as a second row R 2 . 
         [0040]    The holder  20  may be disposed between neighboring rows, for example, between the first row R 1  and the second row R 2 . The holder  20  may directly contact the side surfaces of the battery cells  10  forming the first and second rows R 1  and R 2  while being disposed between the first row R 1  and the second row R 2 . A first surface of the holder  20  may contact the side surfaces of the battery cells  10  forming the first row R 1 , and a second surface of the holder  20 , which is opposite to the first surface, may contact the side surfaces of the battery cells  10  forming the second row R 2 . 
         [0041]    At least one of a first surface  203 A (see  FIG. 2 ) and a second surface  203 B (see  FIG. 2 ) of the holder  20  may include a first receiving groove  211  (see  FIG. 2 ) that receives a temperature device  31  (see  FIG. 2 ). For example, the temperature device  31  may be received in the first receiving groove  211  formed on the first surface of the holder  20 . The holder  20  and the row (first row R 1  or second row R 2 ) of battery cells  10  may contact each other while the temperature device  31  is received in the first receiving groove  211  of the holder  20 . Accordingly, the temperature device  31  may obtain temperature information with respect to the side surface of the battery cell  10 . 
         [0042]    A top surface and a bottom surface of the battery cell  10  may be exposed to the outside. Accordingly, heat of the battery cell  10  may be easily dissipated by external air or may be transmitted to a component such as a bus bar. Therefore, if the temperature were to be measured by a temperature device that contacts the top surface of the battery cell  10 , such temperature measurement may fail to fully reflect the actual temperature resulting from the heating of the battery cell  10 . 
         [0043]    According to an embodiment, the first receiving groove  211  configured to receive the temperature device  31  may be provided on at least one of the first and second surfaces  203 A and  203 B contacting the side surface of the battery cell  10 . Accordingly, the temperature device  31  may measure the temperature of the side surface of the battery cell  10 . The temperature measurement taken at the side surface of the battery cell  10  may be less affected by other external components than the temperature measurements taken at the top surface or the bottom surface of the battery cell  10 . Therefore, the temperature device  31  may be disposed to measure the temperature of the battery cell  10  relatively accurately. 
         [0044]    The temperature unit  30  may include the temperature device  31  that measure the temperature of the battery cell  10 , and a wire  32  and a connector  33  that transmit the measured temperature information to the outside. 
         [0045]    The temperature device  31  may be a thermistor, such as, for example, a resistive thermistor that has an electrical resistance that varies according to temperatures. The thermistor may generate an electrical signal corresponding to the temperature of the battery cell  10  to be measured. 
         [0046]    The generated electrical signal may be transmitted to a protection circuit module (not illustrated) through the wire  32  and the connector  33  that are connected to one end of the temperature device  31 . The transmitted signal may be used to monitor a temperature change of the battery cell  10  and control a charge/discharge operation of the battery cell  10 . Based on the temperature information received from the temperature device  31 , the protection circuit module may prevent overheating and explosion that may be caused by an overcharge, overdischarge, or overcurrent of the battery cells  10 . To this end, the protection circuit module may include a protection device. The protection device may selectively include safety elements, for example, passive elements such as resistors and capacitors or active elements such as field-effect transistors, or integrated circuits. 
         [0047]    The holder  20  may include a cooling hole  213  that extends in a direction identical or parallel to the extension direction (longitudinal direction, z direction) of the battery cell  10 . As will be described later, the holder  20  may be assembled to directly contact the battery cells  10  forming neighboring rows while being disposed between the neighboring rows. Heat may be generated when the battery cell  10  is repeatedly charged and discharged. When the generated heat is not dissipated, the battery cell  10  may become overheated and may not perform a normal operation. In order to prevent an abnormal operation of the battery cell  10  due to the overheating, the holder  20  may include the cooling hole  213  that is disposed between the adjacent rows. 
         [0048]    The pair of end holders  41  and  42  may be disposed at the outermost portion of the battery cells  10  that are arranged to form rows and columns. For example, the pair of end holders  41  and  42  may include a first end holder  41  that is disposed adjacent to one end row of the battery cells  10 , and a second end holder  42  that is disposed adjacent to the other end row of the battery cells  10  to face the first end holder  41 . 
         [0049]    One surface of the first end holder  41  may directly contact the first row R 1 . For example, one surface of the first end holder  41  may be disposed to directly contact and face the side surfaces of the battery cells  10  forming the first row R 1 . 
         [0050]    One surface of the second end holder  42  may directly contact the m-th row Rm that is at an opposite end of the battery pack from the first row R 1 . For example, one surface of the second end holder  42  may be disposed to directly contact and face the side surfaces of the battery cells  10  forming the m-th row Rm. 
         [0051]    The first end holder  41  and the second end holder  42  may be mechanically coupled by coupling members  51  and  52  while the first end holder  41  and the second end holder  42  are disposed at the outermost portions of the battery cells  10 . After disposing the first and second end holders  41  and  42  at the outermost portions of the battery cells  10  having the holder  20  between the neighboring cells, by using the coupling members  51  and  52 , the battery cells  10 , the holder  20 , and the first and second end holders  41  and  42  may be coupled to form one united body. 
         [0052]    The coupling members  51  and  52  may include a bar-type bolt  51  that extends through the first and second end holders  41  and  42  and the holder  20 , and a nut  52  that is coupled to one end of the bolt  51 . The battery cells  10 , the holder  20 , and the first and second end holders  41  and  42  may be coupled in one united body by coupling the nut  52  and one end of the bolt  51  after inserting the bolt  51  into a through hole H formed at the holder  20  and the first and second holders  41  and  42  such that the bolt  51  passes through the holder  20  and the first and second holders  41  and  42 . 
         [0053]    The first and second bus bars  61  and  62  may be disposed respectively at the positions corresponding to the top surface and the bottom surface of the battery cells  10 , and may electrically couple the battery cells  10 . For example, the battery cells  10  may be connected in parallel by welding the first bus bar  61  to the top surface of the battery cells  10  and welding the second bus bar  62  to the bottom surface of the battery cells  10 . 
         [0054]    The first bus bar  61  may include a hole  61   h  that is formed at a position corresponding to the cooling hole  213  formed at the holder  20 . As described above, the first bus bar  61  may be welded onto the top surface of the battery cells  10 . If the hole  61   h  were not formed at the first bus bar  61 , the cooling hole  213  could be blocked and thus the cooling of the battery cells  10  could be difficult. 
         [0055]    The second bus bar  62  may include a hole  62   h  that is formed at a position corresponding to the cooling hole  213  formed at the holder  20 . As described above, the second bus bar  62  is welded onto the bottom surface of the battery cells  10 . If the hole  62   h  were not formed at the second bus bar  62 , the cooling hole  213  could be blocked and thus the cooling of the battery cells  10  could be difficult. 
         [0056]    Although the present embodiment illustrates a case where the battery cells  10  are connected in parallel, in other implementations, the battery cells  10  may be connected in series, or in a series-parallel. 
         [0057]      FIG. 2  illustrates a detailed perspective view depicting the holder  20  and the temperature unit  30  illustrated in  FIG. 1 .  FIG. 3  illustrates a front view of the holder  20  depicted in  FIG. 2 .  FIG. 4  illustrates a perspective view taken along line IV-IV in  FIG. 2 . 
         [0058]    Referring to  FIGS. 2 to 4 , the holder  20  may include first and second edge portions  201  and  202  that are formed at both sides of the holder, and a partition portion  203  that couples the first and second edge portions  201  and  202 . 
         [0059]    The first and second edge portions  201  and  202  may be disposed at both sides of the holder  20 . As described above with reference to  FIG. 1 , the first and second edge portions  201  and  202  may include the through hole H that extends in the x direction such that the coupling members  51  and  52 , for example, the bolt  51 , may pass therethrough. 
         [0060]    The first and second edge portions  201  and  202  may protrude (or extend) in the ±x directions. The first and second edge portions  201  and  202  may protrude in the −x direction, which is a direction from the partition portion  203  toward the battery cells forming the first row, and the x direction, which is a direction from the partition portion  203  toward the battery cells forming the second row. For example, each of the ends of the first edge portion  201  may protrude by the radius of the battery cell  10  in the x direction and the −x direction. Likewise, each of the ends of the second edge portion  202  may protrude by the radius of the battery cell  10  in the x direction and the −x direction. 
         [0061]    Rows of the battery cells  10  may be disposed in parallel to each other, Accordingly, the holders  20  disposed between the rows of battery cells  10  may also be disposed in parallel to each other as illustrated in  FIG. 1 . Referring to  FIG. 1 , the battery cells  10  forming one row may be disposed between the adjacent holders  20 . As described above, the ends of the first and second edge portions  201  and  202  may protrude by the radius of the battery cell  10  in the x direction and the −x direction. Accordingly, the edge portions  201  and  202 , for example, the ends of the first and second edge portions  201  and  202 , of the neighboring holders  20  may contact each other. For example, the first edge portions  201  of the neighboring holders  20  may contact each other, and the second edge portions  202  of the neighboring holders  20  may contact each other. 
         [0062]    The partition portion  203  may extend in the y direction to couple the first and second edge portions  201  and  202 . A first surface  203 A of the partition portion  203  may contact the side surfaces of the battery cells  10  of the first row R 1 , and a second surface  203 B of the partition portion  203 , which is opposite to the first surface  203 A, may contact the side surfaces of the battery cells  10  of the second row R 2 . 
         [0063]    According to an embodiment, the battery cells  10  may be cylindrical. Accordingly, the first and second surfaces  203 A and  203 B of the partition portion  203  may include a recess having a shape corresponding to the side surface of the battery cells  10 . Due to the recess corresponding to the side surface of the battery cells  10 , the partition portion  203  may include a thick portion  203 T that is relatively thick, and a thin portion  203   t  that is relatively thin. As illustrated, for example, in  FIG. 1 , the thick portion  203 T of the partition portions  203  of adjacent holders  20  may contact each other. For example, the thick portions  203 T of adjacent holders  20  may contact each other between adjacent battery cells  10  in a row. 
         [0064]    The first receiving groove  211  configured to receive the temperature device  31  may be formed on the first and second surfaces  203 A and  203 B of the holder  20 , for example, on the first and second surfaces  203 A and  203 B of the partition portion  203 . The first receiving groove  211  may be formed at a center region of at least one of the first and second surfaces  203 A and  203 B such that the temperature of a battery cell  10  disposed at inner side of a row may be measured. For example, when four (even-numbered) battery cells  10  form one row as in the present embodiment, the first receiving groove  211  may be formed at a position corresponding to the side surface of the inner second battery cell  10  or the third battery cell  10 . In another implementation, when five (odd-numbered) battery cells  10  form one row, the first receiving groove  211  may be formed at a position corresponding to the side surface of the center third battery cell  10 . 
         [0065]    The depth of the first receiving groove  211  may be less than or equal to the thickness of the temperature device  31  such that the temperature device  31  seated in the first receiving groove  211  may directly contact the side surface of the battery cell  10 . 
         [0066]    The wire  32  and the connector  33  may be coupled to one end of the temperature device  31 . The connector  33  may be exposed to the outside such that the connector  33  may be connected to an external protection circuit module (not illustrated). At least one of the first and second surfaces  203 A and  203 B of the holder  20  may further include a second receiving groove  212  that is coupled to the first receiving groove  211  and configured to receive the wire  32 . 
         [0067]      FIGS. 2 and 3  illustrate a case where the first receiving groove  211  and the second receiving groove  212  coupled to the first receiving groove  211 , are formed as two pairs. As illustrated in  FIGS. 2 and 3 , when two pairs of first and second receiving grooves  211  and  212  are formed, the temperature unit  30  may be received in any one of the two pairs of first and second receiving grooves  211  and  212 . In other implementations, only one pair of first and second receiving grooves  211  and  212  may be provided. 
         [0068]    The partition portion  203  may include a cooling hole  213  that extends parallel to the longitudinal direction (z direction) of the battery cell  10 . The cooling hole  213  may have a structure that prevents the overheating of the battery cells  10 . The cooling hole  213  may be formed in the longitudinal direction (z direction) of the battery cell  10 . As described above, the first and second end holders  41  and  42 , the holder  20 , and the battery cells  10  may be closely assembled by the coupling members  51  and  52 . IF the heat generated in the battery cells  10  is not dissipated for a long period of time, the battery cells  10  may be deteriorated. 
         [0069]    According to the present embodiment, in order to prevent the deterioration of the battery cells  10 , the cooling hole  213  may be formed at a position adjacent to the battery cells  10 , for example, at the thick portion  203 T of the partition portion  203 . According to the present embodiment, the cooling hole  213  may be provided at the thick portion  203 T formed between side surfaces (i.e., first and second surfaces  203 A and  203 B) of the partition portions  203  that include a recess corresponding to the side surface of the battery cells  10 . Accordingly, space utilization may be maximized. That is, it may not be necessary to increase the thickness of the holder  20  in order to form the cooling hole  213 . 
         [0070]    The top and bottom surfaces of the holder  20 , for example, the top and bottom surfaces of the partition portion  203  may include a stopper  215  that contacts the top and bottom surfaces of the battery cell  10 . As described above, the battery cells  10  may be disposed such that the side surface of the battery cells  10  contacts the holder  20 , and the battery pack may be assembled by the coupling members  51  and  52 . Accordingly, the battery cells  10  are unlikely to become detached in the lateral direction. However, the contact of the side surfaces of the battery cells  10  with the holder  20  does not prevent the battery cells  10  from being separated from the holder  20  in z direction. Accordingly, the holder  20  may include the stopper  215  such that the battery cells  10  are not separated from the holder  20  in the direction of the top surface or bottom surface of the battery cells  10 . Although it is illustrated that the stopper  215  is formed at the thin portion  203   t  of the partition portion  203 , in other implementations, the stopper  215  may be in other suitable positions as long as the stopper  215  contacts the top surface and bottom surface of the battery cells  10  to prevent the battery cells  10  from being detached from the holder  20 . 
         [0071]      FIG. 5  illustrates a detailed perspective view depicting the first and second end holders  41  and  42  according to an embodiment. 
         [0072]    Referring to  FIG. 5 , the first and second end holders  41  and  42  may be disposed such that the surfaces contacting the side surface of the battery cells  10  face each other. When the battery cells  10  are cylindrical as in the present embodiment, one surface  413 A of the first end holder  41  and one surface  423 B of the second end holder  42  may include a recess having a shape corresponding to the side surface of the battery cells. 
         [0073]    The first and second end holders  41  and  42  may respectively include first and second edges  411 ,  412 ,  421  and  422  and partition portions  413  and  423 . 
         [0074]    The first and second edge portions  411  and  412  of the first end holder  41  may be disposed at both sides of the first end holder  41  and may include a through hole H that extends in the x direction such that the coupling members  51  and  52 , for example, the bolt  51 , may pass therethrough, as described above. 
         [0075]    The first and second edge portions  421  and  422  of the second end holder  42  may be disposed at both sides of the second end holder  42  and may include a through hole H that extends in the x direction such that the coupling members  51  and  52 , for example, the bolt  51 , may pass therethrough. 
         [0076]    The first and second edge portions  411  and  412  of the first end holder  41  may protrude in the x direction. For example, ends of the first and second edge portions  411  and  412  of the first end holder  41  may protrude by the radius of the battery cell  10  in the x direction. 
         [0077]    The first and second edge portions  421  and  422  of the second end holder  42  may protrude in the −x direction. For example, ends of the first and second edge portions  421  and  422  of the second end holder  42  may protrude by the radius of the battery cell  10  in the −x direction. 
         [0078]    The partition portions  413  and  423  of the first and second end holders  41  and  42  may extend in the y direction. As described above, one surface of the partition portions  413  and  423  may include a recess having a shape corresponding to the side surface of the battery cells  10  such that the surface may directly contact the side surface of the battery cells  10 . 
         [0079]    The top and bottom surfaces of the first and second end holders  41  and  42 , for example, the top and bottom surfaces of the partition portions  413  and  423  may include a stopper  215  that contacts the top and bottom surfaces of the battery cell  10 . As described above, the battery cells  10  may be disposed such that the side surface of the battery cells  10  contacts the first and second end holders  41  and  42 , and the battery pack may be assembled by the coupling members  51  and  52 . Accordingly, the battery cells  10  are unlikely to become detached in the lateral direction. However, the contact of the side surfaces of the battery cells  10  with the holder  20  does not prevent the battery cells  10  from being separated from the first and second end holders  41  and  42  in z direction. Therefore, the first and second end holders  41  and  42  may include stoppers  415  and  425  such that separation of the battery cells  10  from the first and second end holders  41  and  42  in the direction of the top surface or bottom surface of the battery cells may be prevented or avoided  10 . 
         [0080]    As described above, according to the embodiments, the battery pack may be assembled with the holder  20  interposed between the row of battery cells  10  and the holder  20  may include the first receiving groove  211  that receives the temperature device  31  and the cooling hole  213  that prevents overheating of the battery cell  10 . Accordingly, the battery pack may easily control the temperature of the battery cells  10  while receiving the battery cells  10 . 
         [0081]    By way of summation and review, secondary batteries may be used for a long period of time through multiple charge/discharge operations. Accordingly, the stability of secondary batteries is a matter of great interest. When heat generated during the charge/discharge operation of the secondary batteries, that is, the temperature of the secondary batteries is not properly managed, the secondary batteries may deteriorate, and the lifetime of the secondary batteries may be reduced. Therefore, temperature control in the secondary batteries is desirable. According to the one or more of the above embodiments, the battery packs may easily control the temperature of the battery cells while receiving the battery cells. 
         [0082]    Example embodiments have been disclosed herein, and although specific terms are employed, they are used and are to be interpreted in a generic and descriptive sense only and not for purpose of limitation. Accordingly, it will be understood by those of skill in the art that various changes in form and details may be made without departing from the spirit and scope as set forth in the following claims.