Patent Publication Number: US-2023143369-A1

Title: Battery module, and electric vehicle and power storage device equipped with battery module

Description:
TECHNICAL FIELD 
     The present invention relates to a battery module in which a plurality of battery cells are connected, and an electric vehicle and a power storage device that include the battery module. In particular, the present invention relates to a battery module that supplies power to a motor that is mounted on an electric vehicle such as a hybrid automobile, an electric automobile, a fuel cell automobile, and an electric motorcycle and causes the vehicle to travel, or a battery module for large current that is used for home and factory power storage applications, and an electric vehicle and a power storage device that include the battery module. 
     In the present description, the term “battery module” is used in a broad sense including all battery modules in which a pair of end plates are disposed on both end surfaces of a plurality of battery cells and the end plates are coupled with a binding bar, and including a voltage detection circuit that detects a voltage of a battery cell. Examples of the battery module include a “battery pack” that does not incorporate a controlling circuit such as a charge and discharge controlling circuit which controls charge and discharge electric current. 
     BACKGROUND ART 
     A battery module including a plurality of battery cells is used for a power source for a vehicle such as a hybrid automobile or an electric automobile, a power source of a power storage system for a factory, a home, and the like (e.g., refer to PTL 1). 
     An example of such a battery module is shown in an exploded perspective view of  FIG.  14   . In battery module  900  shown in this figure, a plurality of battery cells  901  are stacked to make battery stack  902 , end plates  903  are disposed on both end surfaces of this battery stack  902 , and the pair of end plates  903  are fastened by binding bars  904  to fix battery cells  901 . In each battery cell  901 , a pair of positive and negative-electrode terminals  911  are disposed on an upper surface of terminal surface  910 . Positive and negative-electrode terminals  911  are electrically connected via bus bar  914  to connect battery cells  901  in series or in parallel. 
     Circuit board  906  connected to each battery cell  901  is disposed on an upper surface of battery stack  902 . A voltage detection circuit that detects a voltage of battery cells  901  is mounted on circuit board  906  so that battery cells  901  can be charged and discharged while being protected. 
     CITATION LIST 
     Patent Literature 
     
         
         PTL 1: WO 2014/024452 A 
       
    
     SUMMARY OF THE INVENTION 
     Technical Problem 
     The above battery module has a disadvantage that the entire battery module is high because the circuit board is disposed on the battery stack. In order to solve this disadvantage, the inventors of the present invention have solved the problem by moving the circuit board from above the battery stack to the surface of the end plate. However, the battery module in which the circuit board is disposed on the surface of the end plate has a disadvantage that the wiring pattern of the circuit board becomes complicated. This is because voltage detection lines are disposed on both sides of the battery stack, and the cell voltage of each battery cell is input to both sides of the circuit board through separate connectors. In this battery module, voltages of respective battery cells are input from separate connectors disposed on both sides of the circuit board, and voltages of a large number of battery cells are sequentially input to both sides of the circuit board. Although the cell voltages input from the separate connectors arranged on both sides are input to the voltage detection circuit via the wiring pattern of the circuit board, this circuit board has a disadvantage that the wiring pattern becomes complicated. 
     The present invention has been developed to further prevent the above adverse effects, and an object of the present invention is to provide a technique for realizing high reliability and safety by simplifying a wiring pattern of a circuit board while reducing a height of a battery module. 
     Solution to Problem 
     A battery module according to an aspect of the present invention includes: a battery stack formed by stacking a plurality of battery cells; a pair of end plates disposed at both ends in a stacking direction of the battery stack; a binding bar formed by connecting the end plates; an electronic circuit block including a voltage detection circuit that detects a voltage of each of the plurality of battery cells; and a plurality of voltage detection lines formed by connecting positive and negative-electrode terminals of the each of the plurality of battery cells and the electronic circuit block. The each of the plurality battery cells has a terminal surface formed by disposing the positive and negative-electrode terminals at both ends, and the battery stack is a stacked body formed by laminating the plurality of battery cells with the terminal surface on the same plane. The electronic circuit block is disposed on an outer surface of each of the end plates and includes a circuit board on which a voltage detection circuit is mounted. In the circuit board, one connector formed by linearly disposing a plurality of connecting terminals formed by connecting voltage detection lines is fixed. In the voltage detection circuit, a plurality of input terminals having adjacent input terminals as input terminals of cell voltages of the battery cells are arranged in a linear manner. In the circuit board, the plurality of connecting terminals and the plurality of input terminals are disposed at opposing positions. The plurality of connecting terminals and the plurality of input terminals at the opposing positions are connected by a plurality of rows of connection lines. The cell voltage of the each of the plurality of battery cells is input to corresponding one of the plurality of connecting terminals connected to corresponding one of the plurality of input terminals by corresponding one of the plurality of connection lines. 
     An electric vehicle according to an aspect of the present invention includes: the above-described the power supply device; a motor for traveling to which electric power is supplied from the power supply device; a vehicle body on which the power supply device and the motor are mounted; and wheels driven by the motor to cause the vehicle body to travel. 
     A power storage device according to an aspect of the present invention includes the above power supply device, and a power supply controller that controls charging and discharging of the power supply device. The power supply controller enables charging of the plurality of stacked battery cells with electric power from outside and controls the charging of the plurality of stacked battery cells. 
     Advantageous Effect of Invention 
     The battery module described above protects the electronic circuit block including the voltage detection circuit from high-temperature, high-pressure exhaust gas to achieve high safety while reducing height, and can efficiently dissipate heat from the electronic circuit block. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective view of a battery module according to a first exemplary embodiment of the present invention. 
         FIG.  2    is an exploded perspective view of the battery module illustrated in  FIG.  1   . 
         FIG.  3    is a cross-sectional view taken along line of the battery module illustrated in  FIG.  1   . 
         FIG.  4    is a broad perspective view of the battery module according to the first exemplary embodiment of the present invention. 
         FIG.  5    is a schematic plan view of the battery module according to the first exemplary embodiment of the present invention. 
         FIG.  6    is a block diagram illustrating an example of a circuit board of an electronic circuit block. 
         FIG.  7    is a block diagram showing another example of the circuit board of the electronic circuit block. 
         FIG.  8    is a plan view illustrating an end of the battery module illustrated in  FIG.  1   . 
         FIG.  9    is a block diagram showing an example in which a battery module is mounted on a hybrid automobile that travels by an engine and a motor. 
         FIG.  10    is a block diagram showing an example in which a battery module is mounted on an electric automobile traveling only by a motor. 
         FIG.  11    is a block diagram showing an example in which a battery module is used in a power storage device. 
         FIG.  12    is a schematic plan view of a battery module according to a reference example. 
         FIG.  13    is a block diagram showing a circuit board of an electronic circuit block of the battery module illustrated in  FIG.  12   . 
         FIG.  14    is an exploded perspective view of a conventional battery module. 
     
    
    
     DESCRIPTION OF EMBODIMENT 
     First, a subject that the inventors of the present invention focus on will be described. A battery module includes an electronic circuit block including a voltage detection circuit that detects a voltage of each battery cell in order to prevent overcharge and overdischarge of each battery cell. The voltage detection circuit provided in the electronic circuit block is connected to an electrode terminal of a battery cell via a voltage detection line to detect a voltage of each battery cell. The electronic circuit block can be disposed on the upper surface of the battery stack to shorten the voltage detection line, but the battery module having this structure has an adverse effect that high-temperature and high-pressure exhaust gas ejected from the battery cell causes thermal damage to the electronic circuit block. 
     Further, although it is desired to downsize the entire battery module in almost no exception in all applications, the battery module in which the electronic circuit block is disposed on the battery stack has a disadvantage that the overall height becomes high. The battery module is required to have high performance by increasing a charge/discharge capacity with respect to a unit volume, but it is difficult to reduce the entire battery module in which an electronic circuit block is disposed on a battery stack. Specifically, examples of the component disposed on the upper surface of the battery stack include a gas duct for discharging exhaust gas, an electrode terminal protruding from a terminal surface, a bus bar of a metal sheet for connecting adjacent electrode terminals, and an insulating material for insulating the component from the high-voltage battery stack. However, since most of these components are disposed so as not to interfere with each other, it is difficult to lower the overall height of the battery module in which the electronic circuit block is further disposed. 
     Thinning the electronic circuit block disposed on the upper surface of the battery stack is effective in reducing the overall height, but it is difficult to dissipate heat energy of the heat generating component mounted on the electronic circuit block. Since a heat generating component such as a semiconductor element or a discharge resistor is mounted on the electronic circuit block, it is extremely important to efficiently dissipate heat energy to lower a temperature rise of the heat generating component below a set temperature. 
     In the battery module, the overall height can be lowered by disposing the electronic circuit block not on the battery stack but on the outer surface of the end plate. The battery module includes a battery stack in which a plurality of battery cells are stacked, a pair of end plates disposed at both ends in a stacking direction of the battery stack, a binding bar connecting the pair of end plates, and an electronic circuit block on which a voltage detection circuit for detecting a voltage of the battery cell is mounted. The electronic circuit block is disposed on the outer surface of the end plate disposed at both ends of the battery stack, and is connected to each battery cell via a voltage detection line. In battery module  60 , as shown in the plan view of  FIG.  12   , voltage detection line  79  connected to electrode terminal  71  of each battery cell  61  is wired on the upper surface of battery stack  62 , that is, the terminal surface of battery cell  61 , voltage detection line  79  is connected from the upper surface of battery stack  62  to electronic circuit block  66  on the surface of end plate  63 , and the voltage of each battery cell  61  is detected by a voltage detection circuit (not illustrated) of electronic circuit block  66 . Since positive and negative-electrode terminals  71  of battery cells  61  are arranged on both sides of battery stack  62 , voltage detection lines  79  connected to electrode terminals  71  are arranged as two rows of wire harnesses on both sides of battery stack  62 , and two sets of connectors  77  for connecting to electronic circuit block  66  are connected to each wire harness. Since battery stack  62  connects a large number of battery cells  61 , the two sets of connectors  77  connect voltage detection lines  79  connected to battery cells  61  to connecting terminals  78  in the order of lamination. 
     As illustrated in  FIG.  13   , in electronic circuit block  66 , voltage detection circuit  72  is mounted on circuit board  65 , and connector  77  is also mounted. Circuit board  65  is provided with, as wiring pattern  75 , connection line  74  that connects input terminal  73  of voltage detection circuit  72  to connecting terminal  78  of connector  77 . Input terminals  73  of voltage detection circuit  72  are connected to connection lines  74  of circuit board  65 , connecting terminals  78  of connector  77 , and electrode terminal  71  of each battery cell  61  via voltage detection line  79  to detect the voltage of battery cell  61 , that is, the cell voltage. Since the voltage of each battery cell  61  is detected via the two sets of connectors  77 , as illustrated in  FIG.  13   , wiring pattern  75  in which connection lines  74  intersect is formed. This is because connection lines  74  alternately connect connecting terminals  78  of the two sets of connectors  77  to input terminals  73  of voltage detection circuit  72  in order. Circuit board  65  of wiring pattern  75  where connection lines  74  intersect has, for example, a complicated structure in which wiring patterns  75  are provided on both surfaces and are connected by through-holes, which increases manufacturing cost. Further, long and complicated connection lines  74  are susceptible to noise, and there is a disadvantage that the detection accuracy of the cell voltage decreases. The power supply module described in the following embodiment solves the above disadvantages with a unique structure. 
     Hereinafter, the present invention will be described in detail with reference to the drawings. Note that, in the following description, terms (e.g., “top”, “bottom”, and other terms including those terms) indicating specific directions or positions are used as necessary; however, the use of those terms is for facilitating the understanding of the invention with reference to the drawings, and the technical scope of the present invention is not limited by the meanings of the terms. Further, parts denoted by the same reference marks in a plurality of drawings indicate the same or equivalent parts or members. 
     Furthermore, exemplary embodiments to be described below show a specific example of the technical idea of the present invention, and the present invention is not limited to the exemplary embodiments below. Further, unless otherwise specified, dimensions, materials, shapes, relative dispositions, and the like of the configuration components described below are not intended to limit the scope of the present invention only to them, but are intended to be illustrative. Furthermore, the contents described in one exemplary embodiment or example are also applicable to other exemplary embodiments and examples. Additionally, sizes, positional relationships, and the like of members illustrated in the drawings may be exaggerated for clarity of description. 
     A battery module according to a first exemplary embodiment of the present invention includes: a battery stack formed by stacking a plurality of battery cells; a pair of end plates disposed at both ends in a stacking direction of the battery stack; a binding bar formed by connecting the end plates; an electronic circuit block including a voltage detection circuit that detects a voltage of each battery cell; and a plurality of voltage detection lines formed by connecting positive and negative-electrode terminals of each battery cell and the electronic circuit block. The battery cell has a terminal surface formed by arranging positive and negative-electrode terminals at both ends. The battery stack is a stacked body formed by stacking a plurality of battery cells with the terminal surface on the same plane. The electronic circuit block is disposed on an outer surface of an end plate and includes a circuit board on which the voltage detection circuit is mounted. In the circuit board, one connector formed by linearly arranging a plurality of connecting terminals formed by connecting voltage detection lines is fixed. In the voltage detection circuit, a plurality of input terminals having adjacent input terminals as input terminals of the cell voltage of the battery cell are arranged in a linear manner. In the circuit board, the connecting terminal and the input terminal are arranged at positions facing each other. The connecting terminal and the input terminal at the positions facing each other are connected by a plurality of rows of connection lines. The cell voltage of each battery cell is input to the connecting terminal connected to the input terminal by the connection line. 
     In the above battery module, in addition to lowering the overall height by arranging the electronic circuit block outside the end plate, the circuit board can be produced in large quantity at low cost as a simple wiring pattern. The connection lines connected to the electrode terminals of all the battery cells are connected to one connector. The connecting terminal of the connector and the input terminal of the voltage detection circuit are connected by a short and simple connection line. Therefore, the voltage of the battery cell is detected with high accuracy. Since the battery module controls charging and discharging with the cell voltage, being able to detect the cell voltage with high accuracy is effective for preventing overcharge and overdischarge of the battery cell. Overcharge and overdischarge of the battery cause degradation of the battery. Therefore, the battery module capable of detecting the voltage of the battery cell with high accuracy is effective in suppressing degradation and extending the life. The above features achieved by the battery module are achieved by fixing one connector in which a plurality of connecting terminals connecting voltage detection lines are arranged in a linear manner to a circuit board, arranging input terminals of a voltage detection circuit mounted on the circuit board in a linear form, arranging the connecting terminals of the connectors arranged in a linear form and the input terminals of the voltage detection circuit at opposing positions, providing a plurality of rows of connection lines connecting the connecting terminals and the input terminals at the opposing positions as a simple wiring pattern, and inputting a cell voltage of each battery cell to the input terminals provided adjacent to the voltage detection circuit. 
     In the above battery module, since the electronic circuit block is disposed on the outer surface of the end plates and not disposed on the terminal surface of the battery stack, the electronic circuit block can be protected from the high-temperature, high-pressure exhaust gas ejected by the battery cells while designing the entire battery module to be low. Further, since the end plates are disposed between the battery stack and the electronic circuit block, the end plates can shield the electronic circuit block from the exhaust gas of the battery cells to protect the electronic circuit block from the high-temperature, high-pressure exhaust gas. Therefore, the normal operation of the electronic circuit block is guaranteed even in an abnormal state, and high safety is guaranteed. In addition, since heat generated by the electronic circuit block can be efficiently dissipated to the end plates, a temperature rise of the electronic circuit block can be reduced. Furthermore, the electronic circuit block is disposed on the surface of the end plates in a vertical posture, so that cooling efficiency can be increased by the air smoothly convecting on the surface of the electronic circuit block. Even in a circuit configuration in which the electronic circuit block is downsized and heat is concentrated in a narrow region, the structure capable of efficiently dissipating heat from the electronic circuit block can guarantee a more stable operation by reducing a local temperature rise and also reducing a temperature rise of a heat-generating electronic component of the electronic circuit block. 
     In the battery module according to a second exemplary embodiment of the present invention, a wiring pattern in which the connection lines do not intersect each other is provided on the surface of the circuit board, and the connection lines input the cell voltages of the respective battery cells to adjacent input terminals of the voltage detection circuit. 
     In the above battery module, since the wiring pattern in which the plurality of rows of connection lines do not intersect is provided on the surface of the circuit board, a large amount of wiring patterns formed on the circuit board can be produced at low cost as a simple structure. 
     In the battery module according to a third exemplary embodiment of the present invention, the battery stack includes the terminal surface of the battery cell arranged on the upper surface and the voltage detection line wired on the upper surface of the battery stack, and the connector provided on the circuit board of the electronic circuit block includes the plurality of connecting terminals arranged in a linear shape extending along the upper edge of the circuit board. 
     In the battery module described above, the battery stack includes the terminal surface of the battery cell disposed on the upper surface, and the voltage detection line is wired on the upper surface of the battery stack. In this specification, the “upper surface” of the battery stack means the terminal surface of the battery cell. Therefore, for example, in a battery module used in a lying posture in which the battery stack of  FIG.  1    rotates 90 degrees, the upper surface of the battery stack is a side surface. 
     In a battery module according to a fourth exemplary embodiment of the present invention, a plurality of input terminals provided in a voltage detection circuit mounted on a circuit board are arranged extending in the same direction as the connecting terminals. 
     In a battery module according to a fifth exemplary embodiment of the present invention, a plurality of input terminals provided in a voltage detection circuit mounted on a circuit board are arranged in a linear manner extending in the same direction as the connecting terminals. 
     In the battery module according to a sixth exemplary embodiment of the present invention, the circuit board is a wiring pattern in which a plurality of rows of connection lines are arranged in parallel. 
     In a battery module according to a seventh exemplary embodiment of the present invention, adjacent connecting terminals of a connector are connected to voltage detection lines connected to positive and negative-electrode terminals of battery cells arranged at both ends of a terminal surface of a battery cell, and a cell voltage of each battery cell is input to the adjacent connecting terminals. 
     In the battery module according to an eighth exemplary embodiment of the present invention, the voltage detection circuit is a circuit that detects a voltage of adjacent input terminals as a cell voltage. 
     In the battery module according to a ninth exemplary embodiment of the present invention, the connecting terminals of the connectors are arranged linearly. 
     In the battery module according to a tenth exemplary embodiment of the present invention, the input terminals of the voltage detection circuit are arranged linearly. 
     In the battery module according to an eleventh exemplary embodiment of the present invention, the voltage detection line is a wire harness. 
     First Exemplary Embodiment 
     The battery module shown in the following example is mainly optimal for a power source of an electric vehicle such as a hybrid automobile or a plug-in hybrid automobile that runs by both an engine and a motor, an electric automobile that runs only by a motor, and an electric motorcycle that runs by a motor. However, the battery module of the present invention is also suitable for a power source for a power storage device that is an application requiring a large output other than an electric vehicle. 
     Battery module  10  shown in  FIGS.  1  to  4    includes battery stack  2  in which a plurality of battery cells  1  are stacked in a thickness, a pair of end plates  3  disposed at both ends in a stacking direction of battery cells  1  of battery stack  2 , binding bar  4  coupled to end plates  3  at both ends of battery stack  2 , and electronic circuit block  6  on which a voltage detection circuit is mounted which detects the voltage of battery cells  1  of battery stack  2 . Furthermore, battery module  10  shown in the figures includes gas duct  5  coupled to an opening of exhaust valve  1   a  provided in each battery cell  1 , upper surface cover  8  disposed above battery stack  2  and on gas duct  5 , and base plate  9  disposed below the battery stack and fixing end plates  3 . 
     (Battery Cell  1 ) 
     As illustrated in  FIG.  2   , battery cell  1  is a rectangular secondary battery having a width larger than the thickness, in other words, thinner than the width, and battery cells  1  are stacked in the thickness to form battery stack  2 . Battery cell  1  is a lithium-ion secondary battery. However, the battery cell may be any other chargeable secondary battery, such as a nickel metal hydride battery and a nickel cadmium battery. In battery cell  1 , positive and negative electrode plates are housed in an exterior can having a sealed structure together with an electrolyte solution. The exterior can is formed by press-molding a metal sheet made of aluminum, an aluminum alloy, or the like into a rectangular shape, and an opening is hermetically sealed with a sealing plate. The sealing plate is made of the aluminum or aluminum alloy same as the exterior can, and fixes positive and negative-electrode terminals  11 , and an exhaust valve  1   a  is provided between electrode terminals  11 . Positive and negative-electrode terminals  11  are in a state where at least one of electrode terminals  11  is insulated from the sealing plate. Battery cell  1  is provided with positive and negative-electrode terminals  11  with the sealing plate as terminal surface  1 X. In battery cell  1 , a bottom surface and a side surface of the exterior can are covered with an insulating film. 
     The plurality of battery cells  1  are stacked to allow the thickness of each battery cell  1  to be aligned with the stacking direction to constitute battery stack  2 . Terminal surface  1 X provided with positive and negative-electrode terminals  11  is disposed on the same plane, and thus the plurality of battery cells  1  are stacked to form terminal surface  2 X, thus forming battery stack  2 . 
     (Battery Stack  2 ) 
     As illustrated in  FIG.  2   , in battery stack  2 , insulating spacer  12  is held between stacked battery cells  1 . Insulating spacer  12  in the figure is made of an insulating material such as resin formed into a thin plate shape or a sheet shape. Insulating spacer  12  illustrated in the figure has a plate shape having substantially the same size as an opposing surface of battery cell  1 . Insulating spacer  12  is stacked between adjacent battery cells  1  and insulates adjacent battery cells  1  from each other. As the spacer arranged between adjacent battery cells  1 , a spacer having a shape in which a flow path of a cooling gas is formed between the battery cell and the spacer may also be used. 
     In battery stack  2 , bus bars  14  made of metal are connected to positive and negative-electrode terminals  11  of adjacent battery cells  1 . The plurality of battery cells  1  are connected in series or in parallel or in series and in parallel by bus bars  14 . In battery stack  2 , the output voltage and the chargeable and dischargeable capacity are set as setting values by the number of battery cells  1  to be stacked. In battery stack  2 , the output voltage can be increased by the number of battery cells  1  connected in series and increasing the charge and discharge capacity by the number of battery cells  1 . In battery module  10 , the output voltage and the capacity are set as setting values by the number of battery cells  1  constituting battery stack  2  and the connection state of connecting in series and in parallel. Therefore, the number of battery cells  1  and the connection state are in an optimal state in consideration of the application. 
     Bus bar  14  is provided with a connection part (not illustrated) for connection to electrode terminal  11 . Bus bar  14  is welded and connected to electrode terminal  11  by irradiating a boundary connecting the connection part and electrode terminal  11  with a laser beam. The bus bar may be coupled to the electrode terminal by providing a male screw in the electrode terminal, opening a through-hole for inserting the electrode terminal, and screwing a nut into the male screw of the electrode terminal inserted in the through-hole, or may be coupled to the electrode terminal by providing a female screw hole in the electrode terminal, and screwing a set screw penetrating the bus bar into the female screw hole. In battery module  10 , an upper surface of battery stack  2  can be provided with a resin insulating cover (not illustrated). The insulating cover is provided with an opening, electrode terminal  11  is exposed from this opening, bus bar  14  of a metal sheet is connected to electrode terminal  11  exposed from the opening of the insulating cover on the upper surface side of the insulating cover, and the plurality of battery cells  1  can be connected in a predetermined array. 
     (End Surface Spacer  13 ) 
     In battery stack  2 , end plates  3  can be arranged on both end surfaces with end surface spacers  13  sandwiched therebetween in order to insulate the battery stack from end plates  3  made of metal. End surface spacers  13  are arranged between battery stack  2  and end plates  3  to insulate end plates  3  from battery stack  2 . Each end surface spacer  13  is made of an insulating material such as resin and formed into a thin plate shape or a sheet shape. End surface spacer  13  is provided with a plate part having a size capable of covering the entire opposing surface of battery cell  1 , and this plate part is stacked between battery cell  1  and end plates  3  arranged at both ends of battery stack  2 . 
     (End Plate  3 ) 
     End plates  3  are provided on both end surfaces of battery stack  2  in the stacking direction of battery cells  1 , and fix battery stack  2 . End plate  3  is a metal sheet and is a quadrangular plate whose outer shape is substantially equal to the outer shape of battery cell  1  or slightly larger than battery cell  1 . End plate  3  can be made of a high-tensile strength steel to have a tough structure. End plate  3  can be a single metal sheet, can have a structure in which a plurality of metal sheets are stacked, or can be a stacked body of a metal sheet and plastic. End plate  3  made of one metal sheet has a large heat capacity, and can efficiently absorb heat energy of electronic circuit block  6 . In end plate  3  on which the plurality of plates are stacked, the surface to which electronic circuit block  6  is fixed is at least a metal sheet. This is because electronic circuit block  6  is fixed in a thermally coupled state and improves heat dissipation characteristics. End plate  3  can be a stacked structure of an aluminum plate and a high-tensile steel plate. This end plate can also have a structure in which the electronic circuit block is fixed with the surface as an aluminum plate, the aluminum plate and the high-tensile steel plate are stacked in a surface contact state, and heat can be efficiently conducted from the aluminum plate to the high-tensile steel plate. However, the end plate is not necessarily made of metal, and may be made of plastic having excellent strength, such as engineering plastic. 
     (Binding Bar  4 ) 
     Binding bar  4  extends in the stacking direction of battery cells  1 , fixes both ends to end plate  3 , and fixes battery stack  2  with the pair of end plates  3 . Each binding bar  4  shown in the figures is a metal sheet having a predetermined vertical width along a side surface of battery stack  2  and a predetermined thickness. Binding bars  4  are disposed so as to oppose both side surfaces of battery stack  2 . Binding bars  4  pressurize both end surfaces of battery stack  2  with a strong pressure, and dispose battery cells  1  about to swell by charging and discharging at a fixed position. As the metal sheet of binding bar  4 , a high tensile strength steel is preferably used. Binding bar  4  made of a metal sheet is formed into a predetermined shape by press-molding. 
     As shown in the exploded perspective view of  FIG.  2   , to fix both ends of binding bar  4  to the pair of end plates  3 , fixing parts  4 A bent along the outer surface of end plate  3  are provided at both ends of binding bar  4  in the stacking direction of battery stack  2 . Binding bar  4  fastens the pair of end plates  3  by, for example, screwing fixing parts  4 A to end plates  3 . 
     Further, as shown in  FIGS.  2  and  3   , a lower end of binding bar  4  is bent into an L shape to form lower coupling piece  4 B. This lower coupling piece  4 B is stacked on the lower surface of both side parts of base plate  9  and coupled to base plate  9 . Binding bar  4  is bent at an upper end to form pressing pieces  4 C that press an end of the upper surface of battery stack  2 . Pressing pieces  4 C are separated for each battery cell  1  so as to individually press upper surfaces of battery cells  1  of battery stack  2 . This allows each pressing piece  4 C to press battery cell  1  toward base plate  9  independently of adjacent pressing pieces  4 C. In this way, each battery cell  1  is blocked from floating from base plate  9  and held in a height direction, and even though vibration, impact, and the like are applied to battery stack  2 , each battery cell  1  can be maintained so as not to be displaced in an up-down direction. In this manner, binding bars  4  cover and hold corners of upper and lower surfaces of battery stack  2  on both left and right sides of battery stack  2 . 
     As for the shape of binding bar  4  and the structure for fastening with end plates  3 , known structures can be appropriately used. For example, both ends of the binding bar may be formed into a flat plate shape without being bent into an L shape and may be screwed with a side surface of the end plate. Alternatively, a part where the binding bar opposes the side surface of the end plate may have an engagement structure to be engaged in a stepped manner, and the binding bar may be further screwed in a state of being locked to the side surface of the end plate with a locking structure. 
     An insulating sheet may be interposed between binding bar  4  and battery stack  2 . The insulating sheet is made of a material having an insulating property such as resin and provides insulation between binding bar  4  made of metal and battery cells  1 . 
     (Base Plate  9 ) 
     As shown in  FIGS.  1  to  3   , base plate  9  is disposed on the bottom surfaces of battery stack  2  and end plate  3 . End plate  3  is fixed to base plate  9 , and more preferably, the lower end part of binding bar  4  is also fixed to base plate  9 . End plate  3  and binding bar  4  are fixed to base plate  9  via fixing screws  15 ,  16 . Fixing screw  15  for fixing end plate  3  penetrates end plate  3  in the up-down direction and fixes end plate  3  to base plate  9 . Fixing screw  16  for fixing binding bar  4  also penetrates lower coupling piece  4 B, which is a lower end of binding bar  4 , and is fixed to base plate  9 . 
     In battery stack  2 , each battery cell  1  is arranged in a thermally coupled state with base plate  9  in contact with base plate  9 . Battery cell  1  thermally coupled to base plate  9  dissipates heat energy to base plate  9 . Base plate  9  may be forcibly cooled to further efficiently dissipate heat energy of battery cell  1 . Although not illustrated, base plate  9  to be forcibly cooled can be forcibly cooled by circulating a refrigerant or a coolant inside of the base plate. The base plate may also be forcibly cooled by providing a heat dissipation fin on the lower surface. The base plate can also be forcibly cooled by a cooling plate stacked in a surface contact state on the lower surface of the base plate. The cooling plate can be forcibly cooled by circulating a refrigerant or a coolant inside of the cooling plate. 
     (Gas Duct  5 ) 
     As shown in  FIGS.  3  and  4   , gas duct  5  is disposed at a position opposite to the upper surface of battery cell  1 , that is, terminal surface  1 X of battery cell  1 , and ejects the exhaust gas ejected from exhaust valve  1   a  to the outside. Gas duct  5  illustrated in  FIG.  4    is disposed at the central portion of terminal surface  2 X of battery stack  2  extending in the stacking direction of battery cells  1 . Gas duct  5  has a cylindrical shape with an inner capacity for smoothly ejecting the discharged material ejected from the opening of exhaust valve  1   a , opens at a lower surface, and is coupled to the opening of exhaust valve  1   a  of each battery cell  1 . Gas duct in  FIG.  4    has a rectangular cylinder shape with a horizontally wide rectangular cross section. So as to eject the exhaust gas ejected from exhaust valve  1   a  to the outside, gas duct  5  is disposed on the upper surface of battery stack  2  in close contact with the upper surface of battery stack  2  so that a gap cannot be formed between the gas duct and terminal surface  1 X of battery cell  1  and opening  5   a  opening on the lower surface is coupled to exhaust valve  1   a  of each battery cell  1 . Gas duct  5  may be arranged so as not to leak the exhaust gas by arranging a packing or sealing material or the like between the gas duct and terminal surface  1 X. 
     Although not illustrated, the gas duct may be configured by a collective duct arranged on the upper surface of the battery stack extending in the stacking direction of the battery cells, and a branch duct coupled to the collective duct and having a tip end coupled to the exhaust valve. In this gas duct, the collective duct can be arranged away from the terminal surface, and the tip end of the branch duct can be coupled to the opening of the exhaust valve. 
     (Electronic Circuit Block  6 ) 
     In battery module  10  of  FIGS.  2 ,  4 , and  5   , electronic circuit block  6  is fixed to an outer surface of end plate  3  that fixes battery stack  2  by pressurization from both ends. As illustrated in  FIGS.  4  and  6   , in electronic circuit block  6 , voltage detection circuit  22  that detects the voltage of battery cell  1  is mounted on circuit board  20 . Electronic circuit block  6  connects voltage detection circuit  22  to electrode terminal  11  of battery cell  1  via voltage detection line  19 . Voltage detection line  19  is wired on an upper surface of battery stack  2  in which terminal surfaces  1 X of battery cells  1  are disposed on the same plane, and connects electrode terminals  11  of respective battery cells  1  to electronic circuit block  6 . All voltage detection lines  19  are connected to electronic circuit block  6  via one connector  17 . 
     Voltage detection line  19  has one end connected to electrode terminal  11  of battery cell  1  and the other end connected to connecting terminal  18  of connector  17 . Voltage detection line  19  in  FIGS.  4  and  5    includes a wire harness. The wire harness connects all voltage detection lines  19  to one connector  17 . However, in the present invention, the voltage detection line does not necessarily need to be a wire harness, and can be formed of a flexible printed circuit board, a flexible flat cable, or the like. 
     Connector  17  connects adjacent connecting terminals  18  to positive and negative-electrode terminals  11  of respective battery cells  1  via respective voltage detection lines  19 . As illustrated in  FIG.  5   , connector  17  connects voltage detection line  19  to connecting terminal  18  such that the cell voltage of each battery cell  1  is input to adjacent connecting terminal  18 . In  FIG.  5   , voltages V 1 , V 2 , V 3 , V 4 , V 5 , V 6 , V 7 , and V 8  of battery cells E 1 , E 2 , E 3 , E 4 , E 5 , E 6 , E 7 , and E 8  stacked in order from the bottom to the top are output between adjacent connecting terminals  18  of connector  17  as follows. 
     In voltages of each battery cell  1 , 
     voltage V 1  is output as a voltage between terminals T 1  and T 2 , 
     voltage V 2  is output as a voltage between terminals T 2  and T 3 , 
     voltage V 3  is output as a voltage between terminals T 3  and T 4 , 
     voltage V 4  is output as a voltage between terminals T 4  and T 5 , 
     voltage V 5  is output as a voltage between terminals T 5  and T 6 , 
     voltage V 6  is output as a voltage between terminals T 6  and T 7 , 
     voltage V 7  is output as a voltage between terminals T 7  and T 8 , and 
     voltage V 8  is output as a voltage between terminals T 8  and T 9 . 
     Connector  17  includes line-side connector  17 A connecting all voltage detection lines  19  and board-side connector  17 B fixed to circuit board  20 , and connects both connectors  17 , so that voltage detection line  19  is connected to electronic circuit block  6 . In line-side connector  17 A, the plurality of connecting terminals  18  connecting voltage detection lines  19  are arranged in a straight line, in the drawing, linearly. In board-side connector  17 B, connecting terminals  18  connected to circuit board  20  are arranged in a straight line so that connecting terminals  18  of the line-side connector  17 A can be connected. Both connectors  17  have an elongated shape in which the plurality of connecting terminals  18  are arranged in a straight line, connect all voltage detection lines  19  to circuit board  20 , and input the voltage of each battery cell to electronic circuit block  6 . 
     In connector  17  of  FIGS.  5  and  6   , the plurality of connecting terminals  18  connecting voltage detection lines  19  are arranged in a straight line of one row, but the connector can also arrange the plurality of connecting terminals in a straight line of two rows. The connector has an elongated shape in which a plurality of connecting terminals are linearly arranged in a plurality of rows, and all voltage detection lines are connected to the circuit board, so that the voltage of each battery cell can be input to the electronic circuit block. In the connectors in which the connecting terminals are arranged in a plurality of linear rows, similarly to the connectors in which the connecting terminals are arranged in a single linear row, the voltage detection lines are connected to the adjacent connecting terminals such that the respective cell voltages are input. 
     Voltage detection circuit  22  mounted on circuit board  20  includes a plurality of input terminals  23  arranged in a linear manner. Voltage detection circuit  22  detects a voltage of battery cell  1  by a voltage input to input terminal  23 . In voltage detection circuit  22 , a plurality of input terminals  23  are arranged in a linear manner, and adjacent input terminals  23  are used as input terminals of the cell voltage of battery cell  1 . Input terminal  23  is connected to connecting terminal  18  of connector  17  via connection line  24  provided as wiring pattern  25  of circuit board  20 . Voltage detection circuit  22  is connected to electrode terminals  11  of respective battery cells  1  via connection line  24 , connector  17 , and voltage detection line  19 . In battery module  10  of  FIG.  4    and  FIG.  5   , adjacent battery cells  1  are connected in series by bus bars  14 , so that voltages of bus bars  14  connected to electrode terminals  11  and positive and negative output terminals  31  are detected to detect voltages of all battery cells  1 . 
     In circuit board  20 , connecting terminal  18  of connector  17  and input terminal  23  of voltage detection circuit  22  are disposed at positions facing each other. By arranging connecting terminal  18  and input terminal  23  at opposing positions, connection line  24  is shortened, and further the lengths are made substantially equal. Therefore, the respective cell voltages can be accurately detected. Connecting terminal  18  and input terminal  23  arranged at the facing positions are connected by a plurality of rows of connection lines  24 . In circuit board  20  of  FIG.  6   , the arrangement direction of connecting terminals  18  of the elongated connector  17  and the arrangement direction of input terminals  23  are arranged in parallel. In input terminal  23  disposed at a position facing connecting terminal  18 , input terminal  23  and connecting terminal  18  are arranged in a linear manner extending in the same direction, and the lengths of connection lines  24  can be substantially equal. Further, as illustrated in  FIG.  7   , circuit board  20  can be arranged such that input terminals  23  are arranged in a line along a mountain shape at a corner portion of electronic component  26  having a rectangular shape in plan view and realizing voltage detection circuit  22 , and input terminals  23  and connecting terminals  18  are arranged in a line shape extending in the same direction. 
     In circuit board  20  of  FIG.  6   , wiring pattern  25  in which the plurality of rows of connection lines  24  do not intersect each other is provided on the surface of circuit board  20 . Circuit board  20  of wiring pattern  25  in which connection lines  24  do not intersect can be produced in large quantities at low cost with a simple structure. The plurality of rows of connection lines  24  connect each connecting terminal  18  to each input terminal  23 . Therefore, the number of connecting terminals  18 , the number of input terminals  23 , and the number of connection lines  24  are the same, and each of connecting terminals  18  is connected to each of input terminals  23  via connection line  24  of each row. Circuit board  20  of  FIG.  6    is provided with wiring pattern  25  having connection lines  24  in a parallel posture on the surface. When the interval between the input terminals is different from the interval between the connecting terminals, the circuit board can be smoothly connected by bending the middle of the connection line extending in the longitudinal direction in the lateral direction and adjusting the interval. 
     Voltage detection circuit  22  is a circuit that detects the voltage of adjacent input terminals  23  as a cell voltage, and detects the voltage of each battery cell  1  via voltage detection line  19 , connector  17 , and connection line  24 . In circuit board  20 , the voltage of each battery cell  1  is input to terminals adjacent to each other in input terminal  23  and connecting terminal  18  disposed at positions facing each other. Therefore, as illustrated in  FIG.  6   , voltage detection circuit  22  detects the voltage of each battery cell  1  by connecting input terminal  23  to electrode terminal  11  of each battery cell  1  via connection line  24  of each row and voltage detection line  19  connected to electrode terminal  11  of each battery cell  1 . In particular, as illustrated in  FIGS.  6  and  7   , connection line  24  connecting terminal  18  and input terminal  23  is provided on the surface of circuit board  20  as wiring pattern  25  that does not intersect with each other. Therefore, connecting terminal  18  and input terminal  23  can be ideally connected via the short connection line  24  while circuit board  20  is inexpensively mass-produced as a simple structure. 
     In electronic circuit block  6 , electronic components for realizing voltage detection circuit  22  are mounted on circuit board  20 . However, electronic circuit block  6  can also be mounted on circuit board  20  as a block in which all the electronic circuits including voltage detection circuit  22  are integrated circuits and the integrated circuits are embedded in a package of an insulating material. 
     Electronic circuit block  6  including voltage detection circuit  22  detects the voltage of battery cell  1  whose voltage fluctuates by charging and discharging, and prevents overcharge and overdischarge of each battery cell  1  with the battery voltage as a set range. In battery module  10 , electronic circuit block  6  may include controlling circuit  30  that controls a charge and discharge current of battery stack  2 . This controlling circuit  30  controls the charge and discharge current to prevent overcharge and overdischarge of battery cell  1 . Voltage detection circuit  22  transmits voltage data of battery cell  1  to the controlling circuit  30 . The electronic circuit block can transmit battery information to an externally provided controlling circuit without providing a controlling circuit, and can control a charge and discharge current of battery module with the external controlling circuit. 
     Voltage detection circuit  22  preferably detects the voltages of all battery cells  1 . However, it is possible for voltage detection circuit  22  not to necessarily detect the voltage of all battery cells  1  but to, for example, divide battery cells  1  constituting battery stack  2  into a plurality of battery units and detect the voltage of each battery unit. The battery unit in which the plurality of battery cells are connected in parallel can detect the voltage of the battery unit and detect the voltages of all the battery cells. A battery unit in which the plurality of battery cells are connected in series detects the voltage of the battery unit and detects the total voltage of the battery cells connected in series. The battery unit in which the plurality of battery cells are connected in series includes 2 to 5 battery cells. Since this battery unit detects the voltage of the battery unit and detects the total voltage of the 2 to 5 battery cells, the voltages of the battery cells become ½ to ⅕ of the total voltage to be detected. The voltage of battery cell  1  changes depending on the remaining capacity. The voltage of battery cell  1  becomes higher than a preset maximum voltage when overcharged, and becomes lower than a minimum voltage when overdischarged. When battery cell  1  is overcharged or overdischarged, electrical characteristics are degraded and the safety also deteriorates. Voltage detection circuit  22  detects the voltage of battery cell  1  and transmits the voltage to controlling circuit  30 , and controlling circuit  30  controls the charge and discharge current such that the voltage of battery cell  1  falls within a set range. 
     Electronic circuit block  6  is fixed to end plate  3  and dissipates heat to end plate  3 . Electronic circuit block  6  includes a heat generating element such as a semiconductor element such as an FET that controls a current. Electronic circuit block  6  can reduce temperature rise by dissipating the heat energy of the heat generating element to end plate  3 . The temperature rise of electronic circuit block  6  adversely affects a built-in heat generating element and the like. Since a temperature rise due to the heat generation energy of the heat generating component leads to a failure of the component, design is performed such that the entire heat generating component is enlarged or a heat generation amount is reduced so that the temperature of the heat generating component does not abnormally rise. When electronic circuit block  6  is downsized so as to enable disposition in a narrow space, a heat dissipation area is reduced, heat dissipation energy is reduced, and a temperature rise is increased. As described above, in order to dispose electronic circuit block  6  in a narrow space, downsizing is required, and in order to improve heat dissipation characteristics, it is necessary to increase the heat dissipation area and increase the size. For this reason, in electronic circuit block  6 , miniaturization and improvement of heat dissipation characteristics are characteristics that are opposite to each other, and both the characteristics cannot be satisfied. A problem that miniaturization required for arrangement in a limited space and high heat dissipation characteristics are contradictory is required. 
     In battery module  10  in which electronic circuit block  6  is fixed to end plate  3  in a thermally coupled state and end plate  3  is used in combination with heat dissipation of electronic circuit block  6 , heat generation energy of electronic circuit block  6  can be efficiently dissipated by end plate  3 . In particular, end plate  3  has an extremely large heat capacity, and can reduce a temperature rise with respect to heat energy to be absorbed. Furthermore, end plate  3  has a large surface area and large heat dissipation energy from the surface, and this also reduces the temperature rise. Furthermore, in the structure for fixing end plate  3  to base plate  9 , heat energy is conducted from end plate  3  to base plate  9 , and the temperature rise is further reduced. In the structure in which base plate  9  is forcibly cooled or cooling plates are stacked on base plate  9 , end plate  3  is forcibly cooled by base plate  9 , the temperature rise is further reduced, the cooling effect of electronic circuit block  6  is further increased, and the temperature rise of electronic circuit block  6  is reduced to an ideal state. 
     In battery module  10  of  FIGS.  1  and  4   , electronic circuit block  6  is fixed to the outer surface of end plate  3 . This battery module  10  has an advantage that heat generation energy of electronic circuit block  6  can be conducted to fixed end plate  3  and dissipate heat, and heat can also be dissipated from the exposed surface to the outside air to dissipate heat more efficiently. The outer shape of electronic circuit block  6  fixed to the surface of end plate  3  is smaller than the outer shape of end plate  3 , and does not protrude from the outer peripheral edge of end plate  3 . In this battery module  10 , while electronic circuit block  6  is disposed on end plate  3 , electronic circuit block  6  does not enlarge the outer shape of battery module  10 , and electronic circuit block  6  can efficiently dissipate heat while being downsized. 
     In battery module  10  of  FIG.  8   , the thickness of electronic circuit block  6  is set to a dimension that does not protrude from the tip edge of base plate  9  to the outer surface in plan view. In this battery module  10 , while electronic circuit block  6  is fixed to end plate  3 , the outer shape in plan view does not become larger than that of base plate  9 , and electronic circuit block  6  can be disposed at an ideal position while being downsized as a whole. 
     Battery module  10  described above can be used as a power source for a vehicle that supplies electric power to a motor that causes an electric vehicle to travel. As an electric vehicle mounted with battery module  10 , an electric vehicle such as a hybrid automobile or a plug-in hybrid automobile that travels by both an engine and a motor, or an electric automobile that travels only by a motor can be used, and battery module  10  is used as a power source of these vehicles. In order to provide electric power that drives the vehicle, it is preferable to mount large-capacity, high-output power supply device  100  in which a plurality of above-described battery modules  10  are connected in series or parallel and a necessary controlling circuit is added. 
     (Power Supply Device for Hybrid Automobile) 
       FIG.  9    illustrates an example in which power supply device  90  connecting a plurality of battery modules is mounted on a hybrid automobile that travels by both an engine and a motor. Vehicle HV illustrated in the figure on which power supply device  90  is mounted includes: vehicle body  91 ; engine  96  and motor  93  for traveling that cause vehicle body  91  to travel; wheels  97  that are driven by engine  96  and motor  93  for traveling; power supply device  90  that supplies electric power to motor  93 ; and power generator  94  that charges a battery of power supply device  90 . Power supply device  90  is connected to motor  93  and power generator  94  via DC/AC inverter  95 . Vehicle HV travels by both motor  93  and engine  96  while charging and discharging the battery of power supply device  90 . Motor  93  is driven in a region where engine efficiency is low, for example, during acceleration or low-speed traveling, and causes the vehicle to travel. Motor  93  is driven by electric power supplied from power supply device  90 . Power generator  94  is driven by engine  96  or by regenerative braking when the vehicle is braked to charge the battery of power supply device  90 . Note that, as illustrated in the drawing, vehicle HV may be provided with charging plug  98  for charging power supply device  90 . Power supply device  90  can be charged by connecting charging plug  98  to an external power source. 
     (Power Supply Device for Electric Automobile) 
       FIG.  10    illustrates an example in which power supply device  90  including a plurality of battery modules is mounted on an electric automobile traveling only by a motor. Vehicle EV illustrated in the figure on which power supply device  90  is mounted includes vehicle body  91 , motor  93  for traveling that causes vehicle body  91  to travel, wheels  97  driven by motor  93 , power supply device  90  that supplies electric power to motor  93 , and power generator  94  that charges the battery of power supply device  90 . Power supply device  90  is connected to motor  93  and power generator  94  via DC/AC inverter  95 . Motor  93  is driven by electric power supplied from power supply device  90 . Power generator  94  is driven by the energy at the time of applying regenerative braking to vehicle EV and charges the battery of power supply device  90 . Further, vehicle EV includes charging plug  98 , and power supply device  90  can be charged by connecting charging plug  98  to an external power source. 
     (Power Supply Device for Power Storage Device) 
     The application of the battery module of the present invention is not limited to a power source for a motor that causes the vehicle to travel. The battery module according to the exemplary embodiment can be used as a power source for a power storage device that performs power storage by charging the battery with electric power generated by photovoltaic power generation, wind power generation, or other methods.  FIG.  11    illustrates a power storage device that performs power storage by charging the battery of power supply device  90  by solar battery  82 . 
     The power storage device illustrated in  FIG.  11    charges a battery of power supply device  90  including a plurality of battery modules with electric power generated by solar battery  82  disposed on a roof, a rooftop, or the like of building  81  such as a house or a factory. The power storage device charges the battery of power supply device  90  via charging circuit  83  with solar battery  82  serving as a charging power source, and then supplies electric power to load  86  via DC/AC inverter  85 . Therefore, the power storage device includes a charge mode and a discharge mode. In the power storage device illustrated in the figure, DC/AC inverter  85  is connected to power supply device  90  via discharging switch  87 , and charging circuit  83  is connected to power supply device  90  via charging switch  84 . Discharging switch  87  and charging switch  84  are turned on and off by power supply controller  88  of the power storage device. In the charge mode, power supply controller  88  turns on charging switch  84  and turns off discharging switch  87  to allow charging from charging circuit  83  to power supply device  90 . Further, when charging is completed and the battery is fully charged or when the battery is in a state where a capacity of a predetermined value or more is charged, power supply controller  88  turns off charging switch  84  and turns on discharging switch  87  to switch the mode to the discharge mode and allows discharging from power supply device  90  to load  86 . Furthermore, it is also possible to simultaneously supply electric power to load  86  and charge power supply device  90  by turning on charging switch  84  and turning on discharging switch  87  as necessary. 
     Further, although not illustrated, the power supply device can be used as a power source for a power storage device that stores electricity by charging a battery using midnight electric power at nighttime. The power supply device that is charged with midnight electric power is charged with the midnight electric power that is surplus electric power generated by a power station, and outputs the electric power during the daytime when an electric power load increases, which can limit peak electric power during the daytime to a small value. Furthermore, the power supply device can also be used as a power source charged with both an output of a solar battery and midnight electric power. This power supply device can effectively utilize both electric power generated by the solar battery and the midnight electric power, and can efficiently store power in consideration of weather and power consumption. 
     The power storage device as described above can be suitably used for applications such as a backup power supply device that can be mounted on a rack of a computer server, a backup power supply device for a radio base station such as a cellular phone, a power source for household or factory power storage, a power source for street lamps, and the like, a power storage device combined with a solar battery, and a backup power source for traffic lights or traffic displays for roads. 
     INDUSTRIAL APPLICABILITY 
     The battery module according to the present invention can be suitably used as a power source for a plug-in hybrid electric automobile and a hybrid electric automobile that can switch between an EV traveling mode and an HEV traveling mode, an electric automobile, and the like. In addition, this battery module and power source device can also be used as appropriate for backup power sources that can be mounted in computer server racks, backup power sources for radio base stations of cellular phones and the like, power storage power sources for homes and in factories, power sources for street lights, power storage devices combined with solar batteries, backup power sources for traffic lights, and the like. 
     REFERENCE MARKS IN THE DRAWINGS 
     
         
         
           
               1 : battery cell 
               1   a : exhaust valve 
               1 X: terminal surface 
               2 : battery stack 
               2 X: terminal surface 
               3 : end plate 
               4 : binding bar 
               4 A: fixing part 
               4 B: lower coupling piece 
               4 C: pressing piece 
               5 : gas duct 
               5   a : opening 
               6 : electronic circuit block 
               8 : upper surface cover 
               9 : base plate 
               10 : battery module 
               11 : electrode terminal 
               12 : insulating spacer 
               13 : end surface spacer 
               14 : bus bar 
               15 : fixing screw 
               16 : fixing screw 
               17 : connector 
               17 A: line-side connector 
               17 B: board-side connector 
               18 : connecting terminal 
               19 : voltage detection line 
               20 : circuit board 
               22 : voltage detection circuit 
               23 : input terminal 
               24 : connection line 
               25 : wiring pattern 
               26 : electronic component 
               30 : controlling circuit 
               31 : output terminal 
               60 : battery module 
               61 : battery cell 
               62 : battery stack 
               63 : end plate 
               65 : circuit board 
               66 : electronic circuit block 
               71 : electrode terminal 
               72 : voltage detection circuit 
               73 : input terminal 
               74 : connection line 
               75 : wiring pattern 
               77 : connector 
               78 : connecting terminal 
               79 : voltage detection line 
               81 : building 
               82 : solar battery 
               83 : charging circuit 
               84 : charging switch 
               85 : DC/AC inverter 
               86 : load 
               87 : discharging switch 
               88 : power supply controller 
               90 : power supply device 
               91 : vehicle body 
               93 : motor 
               94 : power generator 
               95 : DC/AC inverter 
               96 : engine 
               97 : wheel 
               98 : charging plug 
               900 : battery module 
               901 : battery cell 
               902 : battery stack 
               903 : end plate 
               904 : binding bar 
               905 : gas duct 
               906 : circuit board 
               910 : terminal surface 
               911 : electrode terminal 
               914 : bus bar 
             HV, EV: vehicle