Method for manufacturing a battery pack

Abstract

A battery pack manufacturing method is provided. In the battery pack manufacturing method of the present disclosure, a plurality of battery cells each having a terminal disposed on one face are stacked with the one faces facing in the same direction and compressed from both sides, the plurality of battery cells that are compressed are inserted into a case with the one face on the open end side of the case, a plurality of bus bars are disposed on the one face of the plurality of battery cells so as to overlap the corresponding terminals, a pressing jig is moved from a pressing start position so as to push the plurality of bus bars against the bottom surface side of the case from the pressing start position, the pressing start position corresponding to the height position of the terminal of the battery cell that is farthest apart from the bottom surface of the case, and each of the plurality of bus bars is joined to the corresponding terminal. Thus, the joining of the terminals of the plurality of battery cells disposed in the stacked state in the case and the bus bars can be well inhibited from being poor, and the production efficiency of the battery pack can be improved.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a battery pack, the battery pack comprising a housing and a plurality of battery cells arranged in a stacked manner within the housing. Background Technology

[0002] In the past, a battery pack (power supply device) was known, comprising: a covered housing with one end open; a plurality of battery cells, each having a terminal disposed on one side, and stacked within the covered housing with the one side facing the same direction; and a plurality of busbars for connecting the plurality of battery cells in series (see, for example, Patent Document 1). In manufacturing this battery pack, firstly, the plurality of battery cells are stacked, and the stack of battery cells is clamped from both sides using a plurality of clamping jigs arranged sequentially from bottom to top in the height direction. Then, while the clamping jigs are sequentially separated from the stack from bottom to top, the stack is inserted into the covered housing with the terminals of each battery cell on the upper side (open end side). Finally, the stack of battery cells is pressed into the covered housing from above using pressing jigs.

[0003] References

[0004] Patent documents

[0005] Patent Document 1: International Publication No. 2012 / 133711 Summary of the Invention

[0006] In battery packs manufactured in the above manner, since fasteners such as coupling rods are not required, the overall device can be miniaturized and made lighter. However, in the manufacturing of the aforementioned conventional battery packs, it is necessary to limit the load applied to the laminate of the battery cells by the press-fit jig from the point of view of protecting the components. Therefore, even when the laminate is pressed from above and into the housing using the press-fit jig, the height position of the terminals (height from the bottom surface of the housing) will fluctuate among multiple battery cells. As a result, when busbars are arranged on the laminate in a manner that overlaps with the corresponding terminals, the gap between some terminals and the busbars will become larger, posing a risk of poor bonding even if it is attempted to join these terminals to the busbars by welding or the like.

[0007] Therefore, the main objective of this disclosure is to provide a method for manufacturing a battery pack, which can effectively suppress poor connection between the terminals and busbars of multiple battery cells arranged in a stacked state within a housing, thereby improving the production efficiency of the battery pack.

[0008] In the battery pack manufacturing method disclosed herein, the battery pack includes: a housing with one end open; a plurality of battery cells, each of the plurality of battery cells having a terminal disposed on one side, and stacked and housed within the housing with the one side facing the same direction; and a plurality of busbars, each of the plurality of busbars engaging with a corresponding terminal, wherein the plurality of battery cells are stacked with the one side facing the same direction and compressed from both sides, the compressed plurality of battery cells are inserted into the housing with the one side located on the open end side of the housing, the plurality of busbars are disposed on the one side of the plurality of battery cells in a manner overlapping with the corresponding terminal, a pressure clamp is moved from a pressure start position to push the plurality of busbars toward the bottom surface, and each of the plurality of busbars engages with a corresponding terminal, the pressure start position corresponding to the height position of the terminal of the battery cell furthest from the bottom surface of the housing.

[0009] In the battery pack manufacturing method disclosed herein, multiple stacked and compressed battery cells are inserted into a housing with one side of each cell facing the open end of the housing. Furthermore, multiple busbars are arranged on one side of each battery cell, overlapping with their corresponding terminals. A pressure clamp is then moved to push the multiple busbars towards the bottom surface of the housing. At this time, the pressure clamp begins to move from a pressure initiation position, which corresponds to the height position of the terminal of the battery cell furthest from the bottom surface of the housing. Therefore, even if the height positions of the terminals fluctuate among the multiple battery cells, the pressure clamp can sufficiently press the busbars overlapping with the terminals of the battery cells located on the bottom surface of the housing. Thus, according to the method of this disclosure, the busbars and terminals can be joined with a sufficiently reduced gap between each terminal and the busbar. As a result, poor connection between the terminals of the multiple battery cells inserted into the housing in a stacked state and the busbars can be effectively suppressed, improving the production efficiency of the battery pack. Attached Figure Description

[0010] Figure 1 This is a schematic structural diagram showing a battery pack manufactured using the manufacturing method of this disclosure.

[0011] Figure 2 This is a flowchart illustrating the manufacturing method of the battery pack disclosed herein.

[0012] Figure 3 This is an explanatory diagram illustrating the manufacturing method of the battery pack disclosed herein.

[0013] Figure 4 This is an explanatory diagram illustrating the manufacturing method of the battery pack disclosed herein.

[0014] Figure 5 This is an explanatory diagram illustrating the manufacturing method of the battery pack disclosed herein.

[0015] Figure 6 This is an explanatory diagram illustrating the manufacturing method of the battery pack disclosed herein.

[0016] Figure 7 This is an explanatory diagram illustrating the manufacturing method of the battery pack disclosed herein. Detailed Implementation

[0017] Next, the method for carrying out the invention disclosed herein will be described with reference to the accompanying drawings.

[0018] Figure 1 This is a schematic structural diagram showing a battery pack 1 manufactured using the manufacturing method of this disclosure. The battery pack 1 shown is a battery pack installed in a vehicle such as a battery electric vehicle (BEV, FCEV) or a hybrid electric vehicle (HEV, PHEV) and receiving and transmitting power from the vehicle's electric motor. As shown, the battery pack 1 includes a housing 2 and a battery stack 3 housed within the housing 2. The housing 2 is a casting made of a metal such as aluminum alloy, and one end of the housing 2, i.e., the end opposite to the bottom surface 2b of the housing 2 (… Figure 1 The upper part of the housing is open. In this embodiment, the housing 2 is formed to house a single battery stack 3, but it can also be formed, for example, to house multiple battery stacks 3 side by side.

[0019] like Figure 1 As shown, the battery stack 3 includes: multiple battery cells 4, one or more spacers (resin frames) 5 (one less than the number of battery cells 4), multiple (two) end plates 6, and multiple busbars 7. The battery stack 3 is formed by stacking the multiple battery cells 4, spacers 5, and end plates 6 in one direction. More specifically, the battery cells 4 and spacers 5 are arranged alternately between two end plates 6, with one spacer 5 positioned between two battery cells 4. In addition, the multiple battery cells 4 are connected in series by the multiple busbars 7.

[0020] The battery cells 4 of the battery stack 3 are, for example, sealed lithium-ion secondary batteries or nickel-metal hydride secondary batteries, including a metal frame 4c formed in a generally rectangular parallelepiped shape, or electrodes (not shown) housed inside the frame 4c, and a non-aqueous electrolyte. Furthermore, on the upper surface (one face) 4u of each frame 4c, two terminals 4t are respectively connected to the positive or negative electrode plate forming the aforementioned electrodes. Figure 1 In this diagram, only one terminal 4t is shown for each battery cell 4. The terminal 4t of each battery cell 4 is electrically connected to the corresponding terminal 4t of the battery cell 4 via any busbar 7.

[0021] The spacer 5 is formed of an insulating material such as resin, holding two adjacent battery cells 4 together and insulating them. Furthermore, the spacer 5 also functions as a heat dissipation member for the two battery cells 4. The end plate 6 is formed of an insulating metal such as aluminum alloy or resin. Multiple busbars 7 are integrally supported by a module body (not shown) formed of an insulating material such as resin, with the surface and back of the module body exposed to the outside. That is, in this embodiment, multiple battery cells 4 are electrically connected by a busbar module including multiple busbars 7 and the module body. However, multiple busbars 7 can also be configured independently for each of the multiple battery cells 4.

[0022] Next, refer to Figures 2 to 7 The manufacturing method of this disclosure for manufacturing battery pack 1 will be described.

[0023] Figure 2 This is a flowchart illustrating the manufacturing method of battery pack 1. In manufacturing battery pack 1, firstly, battery cells 4 are assembled onto each spacer 5, and multiple battery cells 4 and spacers 5 are stacked such that the upper surfaces 4u, i.e., terminals 4t, of each battery cell 4 face the same direction (upwards) (step S100). Furthermore, in step S100, the battery cells 4 and spacers 5 are stacked such that one spacer 5 is located between two adjacent battery cells 4, and end plates 6 are disposed on both sides of the stack of battery cells 4 and spacers 5.

[0024] like Figure 3 As shown, the stack of battery cells 4, spacers 5, and end plates 6 is compressed from both sides in the stacking direction using a pair of constraint clamps 10 provided in the stacking insertion device (not shown) (step S110). Furthermore, as... Figure 4 As shown, the stacked body, which is compressed and held by the constraint clamp 10, is inserted (pressed in) into the interior from the open end of the housing 2 by the stack insertion device (step S120). Thus, the stacked body of the battery cell 4, spacer 5 and end plate 6 is held in a compressed state by the housing 2 to form the battery stack 3.

[0025] Here, the frame 4c of battery cell 4, the spacer 5, and the end plate 6 are all elastic, and their respective dimensions fluctuate. Therefore, even when the stacked battery cell 4, spacer 5, and end plate 6 are compressed and inserted into the housing 2 using the constraint clamp 10, as... Figure 5 and Figure 6As shown, the height position of the terminal 4t on the upper surface 4u, that is, the height from the bottom surface 2b of the housing 2 to the top of the terminal 4t (the distance in the depth direction (vertical direction) of the housing 2), will also fluctuate among the multiple battery cells 4. Accordingly, in this embodiment, after the battery stack 3 is inserted (assembled) relative to the housing 2, in order to grasp the fluctuation of the height position of the terminal 4t among the multiple battery cells 4, a shape inspection of the battery stack 3 is performed (step S130).

[0026] In step S130, as Figure 5 As shown, using a ranging device 20 such as a laser distance meter, the distance from a predetermined arbitrary reference plane Pref to the top of the terminal 4t is measured for each of the plurality of battery cells 4. In this embodiment, the reference plane Pref is a plane that includes the starting point of the ranging device 20 and is orthogonal to the depth direction of the housing 2. Furthermore, in step S130, the battery cell 4 that is furthest from the bottom surface 2b of the housing 2 (located at...) is obtained. Figure 5 The distance Zh from terminal 4t of the uppermost battery cell 4) to the reference surface Pref, and the distance Zh from the bottom surface 2b of the battery cell 4 closest to the housing 2 (located in...) Figure 5 The distance Zl from terminal 4t of the lowest battery cell 4) to the reference surface Pref. Distance Zh is the minimum distance from the reference surface Pref to the top of terminal 4t measured for all battery cells 4, and distance Zl is the maximum distance from the reference surface Pref to the top of terminal 4t measured for all battery cells 4. In addition, in step 130, the difference ΔZ (=Zl-Zh) between distance Zh and distance Zl is calculated.

[0027] Next, as Figure 6 As shown, busbar modules are arranged on the upper surface 4u of multiple battery cells 4, such that each of the multiple busbars 7 overlaps with the corresponding terminal 4t in the depth direction (vertical direction) of the housing 2 (step S140). At this time, as the battery stack 3 is assembled relative to the housing 2, the height position of each battery cell 4 (terminal 4t) fluctuates, and therefore, as shown, the gap between each terminal 4t and the corresponding busbar 7 also fluctuates.

[0028] After the assembly of multiple busbars 7 (busbar modules) is completed, as follows Figure 7As shown, the housing 2 containing the battery stack 3 is positioned below the pressure fixture 30 of the pressure welding equipment. The pressure fixture 30 includes a movable member 31 that can move up and down in the vertical direction (vertical direction), i.e., in the depth direction of the housing 2, and a plurality of pressing parts 35 supported by the movable member 31. In this embodiment, the movable member 31 supports the same number of pressing parts 35 as the battery cells 4 of the battery stack 3, corresponding to one battery stack 3, and moves up and down in the depth direction of the housing 2 by means of a moving mechanism (not shown) including a motor, etc.

[0029] like Figure 7 As shown, each pressing part 35 of the pressure clamp 30 includes two pressing members 36, two supporting members 37, and two pressing mechanisms 38. Each pressing part 35 is supported by a moving member 31, such that the two pressing members 36 are facing the two terminals 4t of the corresponding battery cells 4 of the battery stack 3. In addition, each supporting member 37 supports the corresponding pressing member 36 in a freely sliding (movable) manner in the moving direction (vertical direction, i.e., the depth direction of the housing 2) of the pressure clamp 30, i.e., the moving member 31, via a linear guide or the like.

[0030] Each pressurizing mechanism 38 is a spring mechanism or servo mechanism that includes an elastic body such as a helical spring, a disc spring, or rubber, and is disposed between the corresponding pressing member 36 and the supporting member 37. Each pressurizing mechanism 38 and the corresponding pressing member 36 move toward the moving member 31, respectively, generating a load corresponding to the amount of movement (pressing amount) of the pressing member 36. In addition, when none of the pressurizing mechanisms 38 of the pressing section 35 generate a load, the contact surfaces (lower end surfaces) of all the pressing members 36 are contained in approximately the same plane.

[0031] When the housing 2, which contains multiple battery cells 4, is positioned below the pressure clamp 30, as follows: Figure 7 As shown, the moving member 31 of the pressurizing clamp 30 is moved by a moving mechanism (not shown) to push (press in) the plurality of busbars 7 toward the bottom surface 2b of the housing 2 (step S150). In step S150, when the moving member 31 moves relative to the housing 2, at least one pressing member 36 (its abutment surface) contacts the corresponding busbar 7. Thus, each pressing member 36 is in a pressurizing start position, which corresponds to the position where the abutment surface (lower end surface) is separated from the reference surface Pref by a distance close to the value of the distance Zh, that is, the height position of the battery cell 4 farthest from the bottom surface 2b of the housing 2.

[0032] Furthermore, in step S150, the moving member 31 is moved (lowered) by the aforementioned moving mechanism so that each pressing member 36 moves (lowers) from the pressurization start position where at least one pressing member 36 (its contact surface) contacts the corresponding busbar 7 towards the bottom surface 2b of the housing 2 by a target movement amount. In this embodiment, the target movement amount of each pressing member 36 is set as the sum of the difference ΔZ calculated in step S130 and a predetermined safety factor (e.g., a few millimeters). Thus, even if a portion of the pressing member 36 is not in contact with the corresponding busbar 7 at the pressurization start position, the pressing member 36 will still abut against the corresponding busbar 7 and push the busbar 7 towards the bottom surface 2b of the housing 2 as the moving member 31 moves (lowers).

[0033] During the movement of the moving member 31 toward the bottom surface 2b of the housing 2, each pressing mechanism 38 of the pressing clamp 30 generates a load corresponding to the amount of movement (pressing in) of the pressing member 36 relative to the support member 37 after abutting the busbar 7. This load is applied from each pressing member 36 to the corresponding busbar 7. As a result, by being pressed by each pressing member 36, each busbar 7 elastically deforms, or a portion of the battery cell 4 is pressed toward the bottom surface 2b of the housing 2, and the gap between each terminal 4t and the busbar 7 is sufficiently reduced.

[0034] When each pressing member 36 moves by the target movement amount (ΔZ + safety factor), the moving member 31 is stopped. Then, a welding machine (e.g., a laser welding machine, not shown in the figure) is inserted into the opening formed in the moving member 31, etc., and using this welding machine, each busbar 7 is welded to the corresponding terminal 4t (step S160). That is, each busbar 7 is welded to the terminal 4t while being pressed relative to the terminal 4t by the corresponding pressing member 36 (pressure clamp 30). Thus, the busbar 7 and the terminal 4t can be joined together while the gap between each terminal 4t and the busbar 7 is sufficiently reduced. When the welding process in step S170 is completed, the manufacturing of one battery pack 1 is finished.

[0035] As described above, during the manufacturing of the battery pack 1, a stack of multiple battery cells 4, etc., compressed by a pair of constraint clamps 10, is inserted into the housing 2 such that their respective upper surfaces (one face) 4u are located at the open end side of the housing 2 (step S120). Furthermore, multiple busbars 7 are arranged on the upper surfaces 4u of the multiple battery cells 4 in a manner overlapping with their corresponding terminals 4t (step S140). Next, the moving member 31 and multiple pushing parts 35 of the pressure clamp 30 are moved to push (press in) the multiple busbars 7 toward the bottom surface 2b of the housing 2 (step S150). At this time, each pushing member 36 of the pressure clamp 30 begins to move from a pressure start position, which corresponds to the height position (height from the bottom surface 2b of the housing 2) of the terminal 4t of the battery cell 4 furthest from the bottom surface 2b of the housing 2. Therefore, even if fluctuations occur at the height of the terminals 4t among multiple battery cells 4, the busbar 7 that overlaps with the terminals 4t of the battery cells 4 located on the bottom surface 2b side inside the housing 2 can be fully pressed by the corresponding pressing member 36 of the pressure clamp 30.

[0036] That is, according to the processing of step S150, for example, compared with the case where the pressing start position of each pressing member 36 (pressurizing clamp 30) is fixed at a position far from the bottom surface 2b and the target movement amount of the moving member 31 is the sum of various design tolerances such as the tolerance of the battery cell 4 or the spacer 5, it is possible to effectively suppress the situation where the busbar 7, which overlaps with the terminal 4t of the battery cell 4 located on the bottom surface 2b side inside the housing 2, is not sufficiently pressed in by the pressurizing clamp 30. Therefore, in the above embodiment, the busbar 7 and the terminal 4t can be welded (joined) (step S160) with the gap between each terminal 4t and the busbar 7 sufficiently reduced, which can shorten the manufacturing time required for the battery pack 1. As a result, it is possible to effectively suppress poor joining between the terminal 4t of the multiple battery cells 4 inserted into the housing 2 in a stacked state and the busbar 7, thereby improving the production efficiency of the battery pack 1.

[0037] Furthermore, in step S150, each pressing member 36 of the pressurizing clamp 30 moves at least ΔZ, the difference between a distance Zh and a distance Zl, from the pressurization start position. The distance Zh represents the height position of the terminal 4t of the battery cell 4 furthest from the bottom surface 2b of the housing 2, and the distance Zl represents the height position of the terminal 4t of the battery cell 4 closest to the bottom surface 2b of the housing 2. This prevents excessive pressing of the busbar 7 relative to the terminal 4t of the battery cell 4 furthest from the bottom surface 2b of the housing 2, and ensures that the pressurizing clamp 30 sufficiently presses the busbar 7 that overlaps with the terminal 4t of the battery cell 4 closest to the bottom surface 2b of the housing 2.

[0038] Furthermore, after the stack including multiple battery cells 4 is inserted into the housing 2 and before the multiple busbars 7 are arranged on the upper surface 4u of the multiple battery cells 4, the distance Zh, distance Zl, and difference ΔZ are obtained (step S130). Thus, the target movement amount of each pushing member 36 (moving member 31) corresponding to the insertion state of the multiple battery cells 4 relative to the housing 2 can be accurately determined from the distances Zh and Zl obtained in step S130. In addition, the reference plane Pref used to obtain the distances Zh and Zl is not limited to a plane containing the starting point of the ranging device 20 as described above; for example, the bottom surface 2b or the inner bottom surface of the housing 2 can also be used as the reference plane Pref.

[0039] Furthermore, in the above embodiment, the pressure clamp 30 includes a plurality of pressing portions 35 that press the corresponding busbars 7 respectively. Each pressing portion 35 includes: a pressing member 36 capable of abutting against the busbar 7; a support member 37 capable of freely supporting the pressing member 36 in the moving direction of the pressure clamp 30 (moving member 31); and a pressure mechanism 38 disposed between the pressing member 36 and the support member 37, generating a load corresponding to the amount of movement of the pressing member 36. Thus, excessive load is not applied to the busbars 7, and each of the plurality of busbars 7 can be correctly pressurized according to the gap with the corresponding terminal 4t, further reducing the gap.

[0040] Furthermore, in the above embodiment, each of the plurality of busbars 7 is pressed on one side by the pressure clamp 30 and welded to the corresponding terminal 4t on the other side (step S160). As a result, poor connection between the terminal 4t of each battery cell 4 and the busbar 7 can be suppressed very well.

[0041] As described above, the method for manufacturing a battery pack disclosed herein includes: a housing with one open end; a plurality of battery cells, each having a terminal disposed on one side, and stacked and housed within the housing with the one side facing the same direction; and a plurality of busbars, each busbar engaging a corresponding terminal, wherein the plurality of battery cells are stacked with the one side facing the same direction and compressed from both sides, the compressed plurality of battery cells are inserted into the housing with the one side located on the open end side of the housing, the plurality of busbars are disposed on the one side of the plurality of battery cells in a manner overlapping with the corresponding terminals, a pressure clamp is moved from a pressure start position to push the plurality of busbars toward the bottom surface, and each of the plurality of busbars is engaged with a corresponding terminal, the pressure start position corresponding to the height position of the terminal of the battery cell furthest from the bottom surface of the housing.

[0042] In the battery pack manufacturing method disclosed herein, multiple stacked and compressed battery cells are inserted into a housing with one side of each cell facing the open end of the housing. Furthermore, multiple busbars are arranged on one side of each battery cell, overlapping with their corresponding terminals. A pressure clamp is then moved to push the multiple busbars towards the bottom surface of the housing. At this time, the pressure clamp begins to move from a pressure initiation position corresponding to the height position of the terminal of the battery cell furthest from the bottom surface of the housing. Therefore, even if the height position of the terminals fluctuates among the multiple battery cells, the pressure clamp can sufficiently press the busbars overlapping with the terminals of the battery cells located on the bottom surface of the housing. Thus, according to the method of this disclosure, the busbars and terminals can be joined with a sufficiently reduced gap between each terminal and the busbar. As a result, poor connection between the terminals of the multiple battery cells inserted into the housing in a stacked state and the busbars can be effectively suppressed, improving the production efficiency of the battery pack.

[0043] Additionally, the pressurizing clamp can also, from the pressurizing start position, move at least the difference between the height position of the terminal of the battery cell furthest from the bottom surface of the housing and the height position of the terminal of the battery cell closest to the bottom surface of the housing. This prevents excessive pressing of the busbar relative to the terminals of the battery cells furthest from the bottom surface of the housing, and ensures that the pressurizing clamp sufficiently presses the busbar that overlaps with the terminals of the battery cells closest to the bottom surface of the housing.

[0044] Furthermore, the method can also, after inserting the plurality of battery cells into the housing and before configuring the plurality of busbars onto one of the surfaces of the plurality of battery cells, obtain the distance from the terminal of the battery cell furthest from the bottom surface of the housing to a predetermined reference surface, and the distance from the terminal of the battery cell closest to the bottom surface of the housing to the reference surface. Thus, based on the obtained distances, the amount of movement of the pressure clamp corresponding to the insertion state of the plurality of battery cells relative to the housing can be accurately determined.

[0045] Alternatively, the pressurizing clamp may also include multiple pressing portions that press against the corresponding busbars. Each pressing portion may include: a pressing member capable of abutting against the busbar; a support member that movably supports the pressing member in the moving direction of the pressurizing clamp; and a pressurizing mechanism disposed between the pressing member and the support member, generating a load corresponding to the amount of movement of the pressing member. This prevents excessive load from being applied to the busbars and allows for accurate pressurization of each of the multiple busbars according to the gap with the corresponding terminal, further reducing that gap.

[0046] Furthermore, the pressurization start position can also be the position where the busbar abuts against at least any one of the pressing members of the plurality of pressing parts.

[0047] Alternatively, the method can also simultaneously press the plurality of busbars using the pressure clamp while welding each of the plurality of busbars to its corresponding terminal. This effectively suppresses poor bonding between the terminals of each battery cell and the busbars.

[0048] Furthermore, it goes without saying that the invention disclosed herein is not limited to any of the embodiments described above, and various modifications can be made within the scope of this disclosure. Moreover, the above embodiments are ultimately just one specific way of the invention described in the summary section, and are not limited to the elements of the invention described in the summary section.

[0049] Industrial practicality

[0050] The invention disclosed herein can be used in the field of battery pack manufacturing, etc.

Claims

1. A method for manufacturing a battery pack, the battery pack comprising: A shell with one end open; A plurality of battery cells, each having a terminal disposed on one side, are stacked and housed within the housing such that the one side faces the same direction; and a plurality of busbars, each connected to a corresponding terminal, wherein... The plurality of battery cells are stacked with one side facing the same direction and compressed from both sides. The compressed battery cells are inserted into the housing with one side facing the open end of the housing. The plurality of busbars are arranged on one surface of the plurality of battery cells in a manner that overlaps with the corresponding terminals. The pressurizing clamp is moved from the pressurizing start position to push the plurality of busbars toward the bottom surface of the housing, the pressurizing start position corresponding to the height position of the terminal of the farthest battery cell separated from the bottom surface of the housing. Each of the plurality of busbars is connected to the corresponding terminal.

2. The method for manufacturing a battery pack as described in claim 1, wherein, From the pressurization start position, the pressurization clamp is moved by at least the difference between the height position of the terminal of the battery cell furthest from the bottom surface of the housing and the height position of the terminal of the battery cell closest to the bottom surface of the housing.

3. The method for manufacturing a battery pack as described in claim 1 or 2, wherein, After the plurality of battery cells are inserted into the housing and before the plurality of busbars are configured on one of the surfaces of the plurality of battery cells, the distance from the terminal of the battery cell furthest from the bottom surface of the housing to a predetermined reference surface, and the distance from the terminal of the battery cell closest to the bottom surface of the housing to the reference surface are obtained.

4. The method for manufacturing a battery pack as described in claim 1 or 2, wherein, The pressurizing clamp includes multiple pressing parts that press the corresponding busbars. Each of the pressing parts includes: a pressing member capable of abutting against the busbar; a support member movably supporting the pressing member in the direction of movement of the pressurizing clamp; and a pressurizing mechanism disposed between the pressing member and the support member, and generating a load corresponding to the amount of movement of the pressing member.

5. The method for manufacturing a battery pack as described in claim 4, wherein, The pressurization start position is the position where the busbar abuts against at least one of the pressing members of the plurality of pressing parts.

6. The method for manufacturing a battery pack as described in claim 1 or 2, wherein, While pressing the plurality of busbars using the pressure clamp, each of the plurality of busbars is welded to the corresponding terminal.

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