Power supply unit capable of replacing battery cell

Abstract

A power supply unit capable of replacing a battery cell, including: a plurality of battery cells, each having an outer peripheral groove on one end side; a battery holder of an insulating material formed by disposing the battery cells at fixed positions; and a spring contact elastically pressed and electrically connected to positive and negative electrodes of the battery cell, in which the spring contact includes a first spring-contact formed by electrically connecting to an end-surface electrode, which is a first electrode of the battery cell, and a second spring-contact formed by electrically connecting to a second electrode of the battery cell, the battery holder includes an attachment / detachment recess part and a fitting claw, the first spring-contact is formed by electrically connecting to the end-surface electrode of the battery cell inserted into the attachment / detachment recess part, and the battery holder is formed by locking the fitting claw to the outer peripheral groove and disposing the battery cell at a fixed position in the attachment / detachment recess part in a state capable of pulling out the battery cell.

Description

Power supply unit with replaceable battery cells

[0001] The present disclosure relates to a power supply unit having a plurality of battery cells, the power supply unit having a "reusable structure" in which the battery cells can be replaced.

[0002] Power supply units can connect multiple battery cells in series or in parallel to optimize output voltage, output current, charge / discharge capacity, and other parameters for specific applications. For example, a power supply unit can achieve a high output voltage by connecting multiple battery cells in series and a high output current by connecting them in parallel, and can optimize charge / discharge capacity by adjusting the number of battery cells connected in series or parallel. Power supply units equipped with multiple battery cells include a battery holder that holds the battery cells in fixed positions. The battery holder is made of insulating material such as plastic. This battery holder is shaped to fit the battery cells in fixed positions. The battery holder positions adjacent battery cells in a parallel orientation, with the end electrodes on both ends aligned flush with each other. The battery holder has electrode windows that expose the end electrodes of the battery cells. Lead plates are positioned to cover the exposure windows and are welded to the end electrodes, connecting adjacent battery cells in series or parallel. A power supply unit that holds multiple battery cells in fixed positions using a battery holder has been developed (see Patent Document 1).

[0003] International Publication No. 2012 / 147134

[0004] The power supply unit described in Patent Document 1 positions multiple cylindrical batteries in fixed positions via a fixing plate. The fixing plate has openings through which the ends of the cylindrical batteries can be inserted to position them in fixed positions. Battery cells are positioned in fixed positions by inserting their ends into the openings in the fixing plate, and connection leads are welded to the end surface electrodes exposed from the openings for series or parallel electrode connection. The fixing plate also has claws that engage with the cylindrical batteries inserted into the openings. The claws engage with grooves in the cylindrical batteries to prevent the battery cells from shifting in the longitudinal direction, and the frictional force acting between the claws and the grooves in the battery cells prevents the battery cells from rotating around their axes.

[0005] In the power supply unit described above, openings are provided in the fixing plate, which corresponds to the battery holder of the present invention, and the battery cells are guided through these openings to arrange multiple battery cells in a parallel position. The rows of batteries held in position by the fixing plate are connected in series or parallel via connection leads welded to the exposed parts of the fixing plate.

[0006] Although the power supply unit described above can be positioned by inserting the ends of battery cells into the openings in the fixing plate, replacing a specific battery cell is extremely difficult. This problem substantially shortens the lifespan of a power supply unit equipped with a large number of battery cells. In a power supply unit consisting of multiple battery cells, the battery cells deteriorate over time as they are charged and discharged. However, the deterioration of each battery cell is not uniform, but rather unbalanced, resulting in a specific battery cell being determined to be a substandard battery cell. Furthermore, during the power supply unit assembly process, a specific battery cell may become a substandard battery cell that does not meet the specified values ​​for some reason. Since not all battery cells deteriorate uniformly, a power supply unit with a specific battery cell that has deteriorated can be restored to a usable state by replacing the deteriorated substandard battery cell, thereby extending the actual lifespan. Therefore, a power supply unit equipped with a large number of battery cells can be reused by replacing the deteriorated substandard battery cell, thereby extending the actual lifespan and making effective use of all battery cells.

[0007] The power supply unit of Patent Document 1 cannot solve the problem of the time-consuming process of replacing, particularly removing and separating, non-standard battery cells, because the end electrodes of the battery cells are welded to the connection leads, which cannot be easily separated.

[0008] The present invention was developed with the aim of resolving the above-mentioned problems, and one of the objects of the present invention is to provide a power supply unit with a reusable structure that allows non-standard battery cells to be simply and easily removed and replaced.

[0009] A power supply unit according to one aspect of the present disclosure comprises a plurality of battery cells each having an outer circumferential groove on one end side, a battery holder made of insulating material in which the battery cells are arranged in fixed positions, and spring contacts that are elastically pressed against and electrically connected to the positive and negative electrodes of the battery cells, one of the positive and negative electrodes being a first electrode and the other being a second electrode, the first electrode being an end surface electrode provided on an end surface of the battery cell, and the spring contacts being a first spring contact electrically connected to the end surface electrode that is the first electrode of the battery cell, and a second spring contact electrically connected to the second electrode of the battery cell. a spring contact, and a battery holder having a removable recess into which the end of each battery cell is inserted in a removable state, and a mating claw that is guided by an outer circumferential groove of the battery cell that is guided in the removable recess and engages the battery cell in a removable state, the first spring contact is located in the center of the bottom surface of the removable recess and is electrically connected to the end surface electrode that is the first electrode of the battery cell inserted in the removable recess, and the battery holder engages the mating claw with the outer circumferential groove to position the battery cell in the removable recess in a fixed position in the removable recess, thereby allowing the battery cell to be replaced.

[0010] The power supply units described above have the advantage that non-standard battery cells can be easily removed and replaced.

[0011] FIG. 1 is a schematic exploded perspective view of a power supply unit according to an embodiment of the present disclosure. FIG. 2 is a cross-sectional schematic view showing a state in which an end of a battery cell is inserted into a battery holder. FIG. 3 is a schematic oblique view of a battery holder. FIG. 4 is a schematic exploded perspective view of the battery holder of FIG. 3. FIG. 5 is a schematic cross-sectional view taken along line V-V of FIG. 3 with a battery cell inserted. FIG. 6 is a schematic cross-sectional view taken along line VI-VI of FIG. 3 with a battery cell inserted. FIG. 7 is a schematic exploded perspective view showing an example of a spring contact connection. FIG. 8 is a schematic exploded perspective view showing another example of a spring contact connection. FIG. 9 is a schematic cross-sectional view showing another embodiment equipped with a sub-battery holder.

[0012] The present invention will be described in detail below with reference to the drawings. In the following description, terms indicating specific directions or positions (e.g., "upper," "lower," and other terms including these terms) will be used as necessary. However, the use of these terms is intended to facilitate understanding of the invention with reference to the drawings, and the meaning of these terms does not limit the technical scope of the present invention. Furthermore, parts that appear with the same reference numerals in multiple drawings indicate the same or equivalent parts or members.

[0013] Furthermore, the embodiments described below are illustrative examples of the technical concepts of the present invention and are not intended to limit the scope of the present invention. Furthermore, unless otherwise specified, the dimensions, materials, shapes, relative positions, and other details of the components described below are intended for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, the content described in one embodiment or example may also be applied to other embodiments or examples. Furthermore, the size and positional relationships of components shown in the drawings may be exaggerated for clarity. For example, Figures 2 and 10 are schematic diagrams for ease of explanation, and the size, scale, and positional relationships of each component are not accurate.

[0014] A power supply unit according to one embodiment of the present disclosure comprises a plurality of battery cells each having an outer peripheral groove on one end side, a battery holder made of insulating material in which the battery cells are arranged in fixed positions, and spring contacts that are elastically pressed against and electrically connected to the positive and negative electrodes of the battery cells, one of the positive and negative electrodes being a first electrode and the other being a second electrode, the first electrode being an end surface electrode provided on an end surface of the battery cell, and the spring contacts being a first spring contact electrically connected to the end surface electrode that is the first electrode of the battery cell, and a second spring contact electrically connected to the second electrode of the battery cell. a spring contact, and a battery holder having a removable recess into which the end of each battery cell is inserted in a removable state, and a mating claw that is guided by an outer circumferential groove of the battery cell that is guided in the removable recess and engages the battery cell in a removable state, the first spring contact is located in the center of the bottom surface of the removable recess and is electrically connected to the end surface electrode that is the first electrode of the battery cell inserted in the removable recess, and the battery holder engages the mating claw with the outer circumferential groove to position the battery cell in the removable recess in a fixed position in the removable recess, thereby allowing the battery cell to be replaced.

[0015] The power supply unit described above allows for the easy removal and replacement of deteriorated or non-standard battery cells because it has a reusable structure in which the end of the electrical connection is guided into the battery holder's attachment / detachment recess to position it in place, mating tabs engage with the outer circumferential groove of the battery cell into which the end is inserted to reliably prevent the battery cell from shifting position during use, and spring contacts are used to electrically connect to the battery cell electrodes.

[0016] When removing a deteriorated or non-compliant battery cell from the power supply unit described above and replacing it with a different power supply unit for reuse, the battery cell can be easily removed from the power supply unit. This is because, unlike conventional power supply units, there is no need to destroy the parts welded to the battery cell electrodes or forcibly pull apart the lead plates. Furthermore, because the battery cell's rear end is exposed by inserting its end into the battery holder's attachment / detachment recess, it can be easily removed by grasping the exposed rear end of the battery holder.

[0017] In another embodiment of the power supply unit of the present disclosure, the second spring contact is arranged to resiliently protrude from the inner surface of the detachable recess and is resiliently pressed against the second electrode to be electrically connected.

[0018] The power supply unit described above has the advantage that the ends of the battery cells can be inserted into the battery holder's attachment / detachment recesses to ensure reliable electrical connection to both the first and second electrodes (positive and negative) of the battery cells. Furthermore, the power supply unit described above allows a cooling plate to be placed directly on the rear end faces of multiple battery cells opposite the first electrode, without any intervening material, and the rear end faces of multiple battery cells can be arranged on the same plane. This simple structure, in which a cooling plate is thermally coupled to the rear end face of each battery cell, allows each battery cell to be cooled efficiently and evenly.

[0019] In another embodiment of the power supply unit of the present disclosure, the battery holder's mating tabs themselves elastically deform to lock the battery cells in the attachment / detachment recesses in a state that allows them to be removed. This power supply unit has the advantage that the mating tabs can be elastically deformed to smoothly insert the battery cells into the attachment / detachment recesses and place them in their designated positions.

[0020] Another embodiment of the power supply unit of the present disclosure includes an outer case housing a plurality of battery cells, the outer case having a battery block therein, the battery block having a plurality of battery cells, the battery block having a plurality of battery packs, and the battery packs can connect the plurality of battery cells in an integrated structure. The above power supply unit has the advantage that the number of battery cells housed in the outer case can be adjusted by mass-producing battery packs in which a specific number of battery cells are connected in an integrated structure and changing the number of battery packs housed in the outer case. This is because the number of battery cells housed in the outer case can be freely changed by connecting the number of battery packs each consisting of a specific number of battery cells.

[0021] In other embodiments of the power supply unit of the present disclosure, the battery cells can be cylindrical. This power supply unit has the advantage that the battery cells can be smoothly guided into the attachment / detachment recess while being rotated, and that the battery cells engaged by the mating claws can be pulled out of the attachment / detachment recess while being rotated.

[0022] In another embodiment of the power supply unit of the present disclosure, the battery pack includes a holder cover formed by connecting multiple battery holders arranged on its surface, and the holder cover has connection leads on its surface that are connected to spring contacts that are connected to adjacent battery holders, allowing adjacent battery cells to be connected in series and / or parallel.The above power supply unit has the advantage that the connection leads on the holder cover can connect the battery cells in the battery holders in series and / or parallel.

[0023] Another embodiment of the power supply unit of the present disclosure includes a sub-battery holder into which the ends of battery cells are inserted to position adjacent battery cells in fixed positions, the sub-battery holder having sub-removable recesses into which the ends of the battery cells are detachably inserted, and one end of each of multiple battery cells is inserted into the removably recess and the other end of the battery cell is inserted into the sub-removable recess, so that each battery cell can be positioned in a fixed position in a parallel posture. Furthermore, this power supply unit has the advantage that the battery holder and the sub-battery holder are fastened together with screws, spacers, etc., and by fixing and fastening the battery holder and the sub-battery holder at a fixed distance, both ends of the battery cells are clamped and the first spring contacts can be stably pressed, allowing the battery cells to be stably positioned in their fixed positions.

[0024] A power supply unit according to another embodiment of the present disclosure can include a circuit board on which a protection circuit is mounted, the protection circuit being electrically connected to the first and second electrodes of the battery cell via the first and second spring contacts. The power supply unit described above has the advantage of being able to achieve high safety by connecting the protection circuit on the circuit board to the first and second electrodes of the battery cell via the first and second spring contacts, and controlling charging and discharging while detecting the electrical characteristics of the battery cell with the protection circuit.

[0025] In another embodiment of the power supply unit of the present disclosure, the battery cell is equipped with a valve opening mechanism that opens to eject waste when the internal pressure exceeds a set pressure, and the battery holder has a discharge opening that communicates with the inside and outside of the attachment / detachment recess and allows the waste ejected from the valve opening mechanism to pass through.This power supply unit has the advantage that high-temperature, high-pressure waste that is released into the attachment / detachment recess due to thermal runaway of the battery cell can be smoothly discharged from the discharge opening that communicates with the inside and outside of the attachment / detachment recess.

[0026] (First Embodiment) A power supply unit 100 shown in the exploded perspective view of Figure 1 has a plurality of battery cells 1 and a circuit board 7 connected to the battery cells 1 arranged inside an exterior case 6. The power supply unit 100 of Figure 1 connects a plurality of battery cells 1 (three battery cells 1 in Figure 1) to form a battery pack 10, and further connects a plurality of battery packs 10 (six battery packs 10 in Figure 1) to form a battery block 11, which is stored in the exterior case 6 as a battery block 11. A power supply unit 100 with this structure has the advantage that the total number of battery cells 1 can be adjusted without changing the number of battery cells 1 that make up the battery pack 10, i.e., by mass-producing a specific number of battery packs 10 and adjusting the number of battery packs 10 that make up the battery block 11. However, the power supply unit 100 of the present invention is not necessarily limited to a structure in which battery cells 1 are connected to form a battery pack 10, and multiple battery packs 10 are connected to form a battery block 11 and placed inside the exterior case 6; for example, it may be a structure in which multiple battery cells 1 are connected to form a battery block 11 and placed inside the exterior case 6.

[0027] The exterior case 6 accommodates multiple battery cells 1 therein. This disclosure does not specify the shape, size, configuration, or structure of the exterior case 6, but for example, the exterior case 6 in Fig. 1 has a box-shaped lower case 6A with an upper opening closed by an upper lid 6B, and accommodates multiple battery cells 1 therein. The exterior case 6 can have a holding portion that holds the battery cells 1 (including the battery block 11 or the battery pack 10) in a predetermined position and posture.

[0028] The battery cells 1 that make up the battery block 11 are connected to a circuit board 7, and charging and discharging can be controlled by a protection circuit (not shown) mounted on the circuit board 7. This circuit board 7 connects the protection circuit to the battery cells 1, and can detect the voltage, current, etc. of the battery cells 1 to control charging and discharging.

[0029] (Battery assembly 10) Multiple battery assemblies 10 are connected to form a battery block 11 housed in the exterior case 6. The battery assembly 10 has battery holders 2 connected to holder covers 17, with multiple battery cells 1 arranged in a parallel position via the battery holders 2. The battery holders 2 position the battery cells 1 in fixed positions. The battery assembly 10 in Figure 1 has three battery cells 1 connected to holder covers 17 via the battery holders 2. In the battery block 11, the holder covers 17 of the battery assembly 10 are arranged in a parallel position on the same plane. The battery block 11 in Figure 1 has holder covers 17 arranged in six rows, with a total of 18 battery cells 1 arranged in a parallel position.

[0030] (Battery Cell 1) The battery cell 1 has positive and negative electrodes 12 housed in an outer can that houses an electrode assembly and is filled with electrolyte. One of the positive and negative electrodes 12 is a first electrode 12a, and the other electrode 12 is a second electrode 12b. In the battery cell 1 shown in Figure 2, the first electrode 12a is an end electrode 13a located on one end surface of the battery cell 1, and the second electrode 12b is a surface electrode 13b located on a surface other than the end electrode 13a. The cross-sectional schematic diagram in Figure 2 shows one end of the battery cell 1 with the end electrode 13a inserted into the battery holder 2. The battery cell 1 shown in Figure 2 has an outer can that is formed by sealing the opening of a metal tube 15 that is closed at the bottom with a sealing plate 14 that has the end electrode 13a. The outer can has a sealing plate 14 with an end electrode 13a provided thereon, which closes the opening of the metal tube 15. An electrode assembly consisting of positive and negative electrode plates is disposed inside the metal tube 15. The sealing plate 14 closes the opening of the metal tube 15 via an insulating material (not shown). The sealing plate 14 and the metal tube 15 are connected in an insulated state, with the end electrode 13a provided on the sealing plate 14 in FIG. 2 and the surface electrode 13b provided on the metal tube 15. The end electrode 13a and the surface electrode 13b are the positive and negative electrodes 12 of the battery cell 1. For example, the end electrode 13a can be a positive electrode and the surface electrode 13b a negative electrode, or the end electrode 13a can be a negative electrode and the surface electrode 13b a positive electrode. The end electrode 13a can be a protruding convex electrode, a concave electrode, or a flat electrode with no or minimal irregularities. The metal tube 15 may have a surface electrode 13b on a portion other than the end electrode 13a, such as the bottom surface or outer peripheral surface (side surface) of the metal tube 15. The battery cell 1 may have the surface electrode 13b located above and / or below the circumferential groove 16, or in the circumferential groove 16. The surface electrode 13b may be located between the circumferential groove 16 and the end face on the end electrode 13a side (first end face 1a), or between the circumferential groove 16 and the end face opposite the end electrode 13a (second end face 1b). The battery cell 1 shown in Figure 5 has the surface electrode 13b located between the circumferential groove 16 and the second end face 1b.

[0031] The sealing plate 14 closes the opening of the metal tube 15 using a crimping structure. This battery cell 1 has a peripheral groove 16 along or near the connecting portion between the sealing plate 14 and the metal tube 15. The peripheral groove 16 connects the sealing plate 14 and the metal tube 15 using a crimping structure and extends circumferentially along or near the connecting portion. The peripheral groove 16 has a stepped portion facing inward (toward the central axis) of the metal tube 15. For example, the battery cell 1 is sealed by crimping the gasket and metal tube 15 after an integrated structure of a tray-shaped gasket and sealing plate 14 is placed on the stepped portion. The peripheral groove 16 can be a groove or step used to press and crimp the metal tube 15. This crimping not only seals the metal tube 15 with the sealing plate 14 but also forms the peripheral groove 16 in the battery cell 1. This battery cell 1 does not require the outer circumferential groove 16 to be formed in a separate process, which saves processes, labor, and time, and contributes to lower costs.

[0032] In the power supply unit 100 of FIG. 1 , the battery cell 1 is a cylindrical battery 1A. However, the present disclosure does not limit the battery cell 1 to a cylindrical battery 1A and can also be a prismatic battery. Prismatic batteries can have peripheral grooves. Furthermore, while the battery cell 1 is a non-aqueous electrolyte secondary battery such as a lithium-ion secondary battery, the present invention does not limit the type of battery cell 1. All currently used or future secondary batteries, such as all-solid-state batteries, can be used.

[0033] (Battery Holder 2) The battery holder 2 positions the battery cells 1 in fixed positions. The battery holder 2 has a removable recess 20 that holds the battery cells 1 in fixed positions. The battery holder 2 positions the battery cells 1 by inserting the ends of the battery cells 1 into the removable recess 20. The ends of the battery cells 1 can be removed from the removable recess 20. The battery holder 2 can be formed and manufactured from a single material or multiple materials. The battery holder 2 can be made from a hard insulating molded material, such as a molded thermoplastic plastic such as polycarbonate. The battery holder 2 can also be molded in parts using different materials, such as two-color molding or insert molding, or can be composed of multiple components. For example, the entire battery holder 2, including the mating tabs 21, can be made of a flexible material, such as polycarbonate, while the areas requiring fire and heat resistance, such as the area around the battery cells 1 (valve opening mechanism 14a) in the removable recess 20, can be made of a material with excellent fire and heat resistance. Alternatively, it can be composed of a separate material, such as mica. This battery holder 2 allows the elastic pressing force of the mating tabs 21 to be adjusted, and is fire-resistant and heat-resistant in the event of thermal runaway. The battery holder 2 can hold one or multiple battery cells 1 in a fixed position. For example, Figures 3 to 6 show a battery holder 2 that holds one battery cell 1 in a fixed position. A battery holder 2 that holds multiple battery cells 1 in fixed positions has multiple attachment / detachment recesses 20. A battery holder 2 with multiple attachment / detachment recesses 20 can be molded and manufactured as an integral structure, and multiple battery holders 2 can also be connected together.

[0034] The power supply unit 100 in Figure 1 has battery holders 2 arranged adjacently, with multiple battery cells 1 arranged in a parallel position. The multiple battery cells 1 can be arranged in a parallel position via the battery holders 2, which are placed in fixed positions within the exterior case 6. The power supply unit 100 can arrange the multiple battery cells 1 in a single or multiple parallel rows within the exterior case 6 via the battery holders 2. Furthermore, the power supply unit 100 can arrange the end faces of the multiple battery cells 1 in the same or nearly the same plane via the battery holders 2, or they can be arranged on different planes. However, the present invention does not specify the arrangement of the battery cells 1, and the multiple battery cells 1 can be arranged in various arrangements and positions.

[0035] The battery holder 2 has an attachment / detachment recess 20 into which one end of a battery cell 1 is inserted and positioned, and mating tabs 21 that hold the battery cell 1 in the attachment / detachment recess 20. The attachment / detachment recess 20 and mating tabs 21 are positioned in the attachment / detachment recess 20 so that the battery cell 1 can be removed. Figure 3 shows the state in which the end of the battery cell 1 is inserted into the battery holder 2, Figure 4 is an exploded perspective view of the battery holder 2, Figure 5 is a schematic cross-sectional view taken along line V-V (between opposing retaining walls 24) in Figure 3 with the end of the battery cell 1 (first end face 1a) inserted, and Figure 6 is a schematic cross-sectional view taken along line VI-VI (between opposing mating tabs 21) in Figure 3 with the first end face 1a of the battery cell 1 inserted. The battery holder 2 shown in Figures 3 to 10 has multiple retaining walls 24 and multiple mating tabs 21 around the periphery of the bottom plate 23. The battery holder 2 in Figure 3 has mating tabs 21 positioned between adjacent retaining walls 24. The retaining walls 24 shown in the figure are positioned diagonally at the four corners of the bottom plate 23 and hold the battery cells 1 in place. The mating tabs 21 shown in the figure are located opposite the center of each side of the periphery of the bottom plate 23 and engage with the outer circumferential grooves 16 of the battery cells 1 to hold the battery cells 1 in place. This battery holder 2 can be manufactured by molding plastic into a shape that integrates the bottom plate 23, retaining walls 24, and mating tabs 21. The battery holder 2 shown in the figure has vertically extending retaining walls 24 positioned at the four corners of the attachment / detachment recess 20, and the inside of the retaining walls 24 forms the attachment / detachment recess 20 that guides the battery cells 1.

[0036] The retaining wall 24 defines the inner surface as the attachment / detachment recess 20, allowing the battery cell 1 to be inserted into the attachment / detachment recess 20 and positioned properly. The height of the retaining wall 24 is determined within an appropriate range to allow the battery cell 1 to be positioned properly, depending on the size of the battery cell 1. For example, the height of the retaining wall 24 is set to 5 mm or more, preferably 10 mm or more, and more preferably 15 mm or more for a 70 mm long battery cell 1, so that the battery cell 1 positioned inside can be held properly without being displaced from its surroundings. A high retaining wall 24 allows the battery cell 1 to be stably positioned in its fixed position. Furthermore, a low retaining wall 24 increases the exposed area of ​​the battery cell 1, improving cooling performance. The inner surface of the retaining wall 24 is shaped to fit the outer periphery of the battery cell 1, allowing the battery cell 1 to be stably held in the attachment / detachment recess 20. The outer shape of the retaining wall 24 can have chamfered corners or orthogonal surfaces, as shown in the perspective view of Figure 3 .

[0037] The bottom plate 23 can be, for example, a plate with flat inner and outer surfaces, and can have a rectangular outer shape or a shape with curved, chamfered corners ( Figures 3 , 8 , and 9 ). Battery holders 2 with rectangular or other rectangular bottom plates 23 have the advantage of being able to arrange the battery cells 1 in multiple rows and columns, with no gaps between them in a checkerboard pattern.

[0038] The battery holder 2 can have one or more mating claws 21. The mating claws 21 in Figure 3 are positioned between adjacent retaining walls 24 and hold the battery cells 1 placed inside the retaining walls 24 in place. The mating claws 21 have locking protrusions 21b that lock into the outer circumferential grooves 16 of the battery cells 1 guided inside the retaining walls 24. The locking protrusions 21b are located at or near the tips of the mating claws 21 and protrude inward, and lock into the outer circumferential grooves 16 of the battery cells 1 guided in the attachment / detachment recesses 20. The mating claws 21 lock into the outer circumferential grooves 16 of the battery holder 2, allowing the inserted battery cells 1 to be positioned and held in place. The shape, size, and number of the mating claws 21 are not specified, but they must be compatible with the depth, width, and step of the outer circumferential groove 16 so that they can be locked into the outer circumferential groove 16. They must also be compatible with the external shape of the battery cells 1 (outer circumferential groove 16). The locking protrusions 21b have a fixed length in the direction in which the outer circumferential groove 16 extends (the outer circumferential direction), allowing them to engage with the outer circumferential groove 16 and reliably position and hold the battery cell 1 in place. In the case of a cylindrical battery 1A, the locking protrusions 21b are preferably arc-shaped. Multiple locking protrusions 21b engage with the outer circumferential groove 16 at different, spaced-apart positions, reliably positioning and holding the battery cell 1 in place. Furthermore, pairs of locking protrusions 21b arranged in opposing positions each protrude inward, allowing them to engage with the outer circumferential groove 16 from both sides and clamp the battery cell 1. The existence of multiple pairs of opposing locking protrusions 21b (two pairs in FIG. 3 ) allows for locking and clamping along multiple axes (two axes in FIG. 3 ). Furthermore, the locking protrusions 21b are spaced apart at a central angle of 90 degrees, allowing pairs of opposing locking protrusions 21b to be arranged in a cross shape and engage and clamp the battery cell 1, ensuring reliable positioning and holding. The power supply unit 100 can position and hold the battery cells 1 in a fixed position using each of the retaining walls 24, the mating claws 21, and the spring contacts 3 (described later) or a combination thereof. The attachment / detachment recess 20 and the mating claws 21 hold the battery cells 1 in the inserted position in the attachment / detachment recess 20, but when replacing a non-standard battery cell 1, the mating claws 21 are positioned in the attachment / detachment recess 20 so that the non-standard battery cell 1 can be pulled and removed.

[0039] The battery holder 2, which holds the cylindrical battery 1A cells 1 in place, can be designed to allow the cylindrical battery 1A to be placed in a rotatable state in the attachment / detachment recess 20. This battery holder 2 has the advantage that when removing a non-standard battery cell 1 from the attachment / detachment recess 20, the cylindrical battery 1A of the battery cell 1 can be rotated to make it easier to remove. However, the attachment / detachment recess 20 does not necessarily need to guide the battery cell 1 in a rotatable manner. This is because a non-standard battery cell 1 can be removed from the attachment / detachment recess 20 by pulling it without rotating it.

[0040] The mating claws 21 can have elastic arms 21a that can be elastically deformed. These mating claws 21 have the advantage that when an out-of-standard battery cell 1 is pulled out, they can elastically deform to move the locking protrusions 21b out of the outer circumferential groove 16, facilitating removal. However, the mating claws 21 do not necessarily have to be elastically deformable. This is because the out-of-standard battery cell 1 can be pulled out of the attachment / detachment recess 20 by pulling the locking protrusions 21b strongly in the removal direction. Cylindrical battery 1A battery cells 1 can be easily removed from the attachment / detachment recess 20 by rotating them and pulling them in the removal direction. A dedicated battery cell 1 removal tool can also be used to move the locking protrusions 21b out of the outer circumferential groove 16, releasing the lock, and then the battery cell 1 can be removed.

[0041] The battery holder 2 can be provided with one or more exhaust openings 22. The exhaust openings 22 communicate with the inside and outside of the attachment / detachment recess 20, allowing exhaust material ejected from the battery cell 1 valve opening mechanism 14a to pass through and be discharged to the outside of the attachment / detachment recess 20. The attachment / detachment recess 20 can be provided with exhaust openings 22 that smoothly discharge high-temperature, high-pressure exhaust gases emitted from the battery cell 1 valve opening mechanism 14a to the outside. The exhaust openings 22 are located in positions that allow exhaust gases and other exhaust material to be smoothly discharged to the outside. For example, as shown by solid lines in Figures 7 and 8, the exhaust openings 22 can be located at the bases of the retaining walls 24. This battery holder 2 has the advantage that exhaust material can be discharged to the outside through the exhaust openings 22 in the multiple retaining walls 24, and that the strong fitting claws 21 can stably hold and position the battery cells 1 in their designated positions. Furthermore, as shown by dotted lines in Figures 7 and 8, the exhaust openings 22 can be located at the bases of the fitting claws 21 of the battery holder 2. This battery holder 2 can discharge waste to the outside from positions and angles different from those of the retaining wall 24, and by increasing the number of openings or enlarging the opening area, waste can be discharged smoothly to the outside. Battery holders 2 with exhaust openings 22 can be arranged in a straight line, as shown in Figure 7, for example, to allow exhaust gas to be discharged to both sides. Exhaust gas discharged from the exhaust openings 22 can be discharged to the outside of the exterior case 6 through exhaust ducts (not shown) provided on both sides of the battery holder 2. The battery holder 2 can also be shaped to guide waste to the exhaust openings 22 within the attachment / detachment recess 20, and ribs or other features can be provided.

[0042] (Spring contact 3, first spring contact 31, second spring contact 32) The spring contact 3 connects to the electrodes 12 of the battery cells 1 that are positioned in fixed positions within the battery holder 2. The spring contact 3 in Figure 3 has a first spring contact 31 and a second spring contact 32. The first spring contact 31 and second spring contact 32 are positioned in fixed positions within the battery holder 2 and are electrically connected to the positive and negative electrodes 12 of the battery cells 1 that are guided into the attachment / detachment recess 20. The first spring contact 31 and second spring contact 32 are positioned in fixed positions within the battery holder 2 and elastically press against the electrodes 12 (first electrode 12a, second electrode 12b) of the battery cells 1 to establish an electrical connection. The first spring contact 31 has a first mounting portion 31a that is attached to the battery holder 2 (bottom plate 23) and a leaf spring-shaped first contact portion 31b that is bent from the first mounting portion 31a into a shape that provides elasticity and springiness. The first spring contact 31 makes electrical connection by bringing the first contact portion 31b into contact with the end surface electrode 13a (first electrode 12a) of the battery cell 1 while the first contact portion 31b elastically presses against the end surface electrode 13a. The second spring contact 32 has a second mounting portion 32a that is attached to the battery holder 2 (bottom plate 23) and multiple leaf spring-shaped second contact portions 32b that are bent from the second mounting portion 32a into a shape that provides elasticity and springiness. The second spring contact 32 makes electrical connection by contacting the multiple second contact portions 32b with the surface electrode 13b (second electrode 12b) of the metal tube 15 of the battery cell 1 while the multiple second contact portions 32b elastically press against the surface electrode 13b from the periphery toward the center (inward). The spring contact 3 can be made of an elastically deformable conductive metal plate. The spring contact 3 can include a first contact portion 31b and a second contact portion 32b that elastically press against the electrode 12 of the battery cell 1 by the elastic restoring force of a leaf spring or the like that is bent into a shape that imparts elasticity and springiness. The elastic restoring force of the spring contact 3 can elastically press the first contact portion 31b of the first spring contact 31 against the first electrode 12a, and the second contact portion 32b of the second spring contact 32 against the second electrode 12b.

[0043] Figures 3 to 9 show examples of battery holders 2 in which both the first spring contact 31 and the second spring contact 32 are positioned in fixed positions. The first spring contact 31 in Figures 3 to 6 has a first mounting portion 31a attached to and fixed on the inner surface of the bottom plate 23 of the battery holder 2, and a first contact portion 31b that passes through a hole 25a in the bottom plate 23 and faces the end surface electrode 13a of the battery cell 1. The second spring contact 32 in Figures 3 to 6 has a second mounting portion 32a attached to and fixed on the outer surface of the bottom plate 23 of the battery holder 2, and multiple second contact portions 32b that pass through a hole 25b in the bottom plate 23 and face the surface electrodes 13b of the battery cells 1 on the inner surface of the retaining wall 24. The first spring contact 31 and second spring contact 32 are pressed against the electrodes 12 of the battery cell 1 inserted into the attachment / detachment recess 20, forming an electrical connection. The first spring contact 31 is connected to the first mounting section 31a and passes through the bottom plate 23, with a first connection terminal 31c exposed on the outer surface of the battery holder 2, which is the outer surface of the bottom plate 23 (Figs. 4 and 6). The second spring contact 32 is connected to the second mounting section 32a and has a second connection terminal 32c exposed on the outer surface of the battery holder 2 (Fig. 4).

[0044] The first spring contact 31 and second spring contact 32 increase the contact pressure with which the leaf spring-shaped first contact portion 31b and second contact portion 32b press against the surface of the battery cell 1 electrode 12, thereby achieving stable electrical connection with the battery cell 1 with low contact resistance. The first spring contact 31 increases the contact pressure with which the first contact portion 31b presses against the end surface electrode 13a, reducing the contact resistance between the first contact portion 31b and the end surface electrode 13a. However, this contact pressure also generates a pushing force that pushes the battery cell 1 out of the attachment / detachment recess 20. This pushing force acts in a direction that pushes the battery cell 1 out of the attachment / detachment recess 20, causing the battery cell 1 to become misaligned. Misalignment of the battery cell 1 inhibits the electrical connection between the battery cell 1 electrode 12 and the spring contact 3, but the battery holder 2 is equipped with mating tabs 21 that prevent the battery cell 1 from becoming misaligned. The mating tabs 21 are guided by the outer circumferential grooves 16 of the battery cell 1, preventing misalignment in the direction of extrusion of the battery cell 1. Therefore, a battery holder 2 with an integral mating tab 21 structure has the advantage of being able to position the battery cell 1 in a fixed position while increasing the contact pressure of the end surface electrode 13a of the first contact portion 31b and maintaining low contact resistance.

[0045] The second spring contact 32 has multiple second contact portions 32b arranged inside the opposing retaining walls 24, which increases the contact pressure between the second contact portions 32b and the surface electrodes 13b, allowing the battery cells 1 to be positioned in a fixed position while preventing misalignment. This is because the opposing second contact portions 32b press the surface electrodes 13b of the battery cells 1 in the opposite direction (inward), thereby clamping the battery cells 1 while canceling out the contact pressure. The second contact portions 32b of the second spring contact 32 increase the contact pressure pressing against the surface electrodes 13b, thereby reducing contact resistance, and further increase the frictional resistance with the surface of the battery cells 1, preventing misalignment of the battery cells 1.

[0046] The first spring contact 31 and the second spring contact 32 position the first contact portion 31b and the second contact portion 32b at the position of the electrode 12 of the battery cell 1 inserted into the attachment / detachment recess 20. In Figure 5, when the first end face 1a of the battery cell 1 is inserted into the attachment / detachment recess 20, the second contact portion 32b of the second spring contact 32 extends below the outer circumferential groove 16 and is in contact with the surface electrode 13b. This second spring contact 32 can contact the surface electrode 13b with the second contact portion 32b over a wide contact area without being restricted by the position of the outer circumferential groove 16. The second spring contact 32 has a leaf spring shape and extends below the outer circumferential groove 16, so that the second contact portion 32b can press against the side of the battery cell 1 at a position away from the first end face 1a, thereby stably positioning and holding the battery cell 1 in a fixed position.

[0047] The multiple second spring contacts 32 are arranged so that pairs of second spring contacts 32 are positioned opposite each other, and by evenly arranging these multiple sets, the battery cell 1 can be stably clamped. Even when the battery cell 1 (power supply unit 100) is vibrated, the contact pressure between the spring contacts 3 and the electrodes 12 is stable, resulting in stable low contact resistance. In Figure 3 , the multiple second spring contacts 32 include two pairs of opposing second spring contacts 32, for a total of four, and the contacts are spaced at 90-degree central angle intervals. While the number of contacts can be increased by increasing the number of second spring contacts 32, using too many second spring contacts 32 can make it difficult to ensure sufficient contact width and may restrict the positional relationship with the mating claws 21. Therefore, for example, it is preferable to arrange the second spring contacts 32 in two pairs of opposing second spring contacts 32, for a total of four, spaced at 90-degree central angle intervals. In Figure 3 , two pairs of second spring contacts 32, for a total of four, are arranged at the four corners of the bottom plate 23. A pair of second spring contacts 32 arranged in opposing positions can be pressed against each other in the push-back direction (inward) to clamp the battery cell 1. The existence of multiple pairs (two sets) of opposing second spring contacts 32 allows for pressing and clamping along multiple axes (two axes). Furthermore, the second spring contacts 32 are arranged at intervals of a central angle of 90 degrees, so that the opposing pair of second spring contacts 32 can be positioned diagonally to press and clamp the battery cell 1, thereby stably clamping the battery cell 1. Furthermore, the second spring contacts 32 can ensure a sufficient contact width, and the mating claws 21 can be positioned between the second spring contacts 32.

[0048] The first spring contact 31 and the second spring contact 32 are connected to the connection leads 18, and can connect adjacent battery cells 1 in series and / or parallel. The first spring contact 31 and the second spring contact 32 shown in Figure 7 connect adjacent battery cells 1 in parallel via the connection leads 18. In this figure, the spring contacts 3 arranged on the inner surfaces of three adjacent battery holders 2 are linked by the connection leads 18 to connect the battery cells 1 in parallel. The first mounting portion 31a of the first spring contact 31 and the second mounting portion 32a of the second spring contact 32 are located on different surfaces across the bottom plate 23 of the battery holder 2, ensuring insulation between the first spring contact 31 and the second spring contact 32. Each first spring contact 31 located on the surface of the bottom plate 23 of each battery holder 2 is connected by a connection lead 18 made of a single metal plate, and each second spring contact 32 located on the inner surface of the retaining wall 24 of each battery holder 2 is connected by a connection lead 18 made of a single metal plate. Each first spring contact 31 and connection lead 18 are made from a single metal plate, and each second spring contact 32 and connection lead 18 are also made from a single metal plate. The metal plate connecting the first spring contact 31 and the connection lead 18, and the metal plate connecting the second spring contact 32 and the connection lead 18 are placed in fixed positions on the battery holder 2, and can also be used to connect adjacent battery holders 2.

[0049] Figures 8 and 9 are exploded perspective views of a battery holder 2, a first spring contact 31, a second spring contact 32, and a holder cover 17 that make up a battery pack 10 containing three battery cells 1. The holder cover 17 shown in these figures has metal plate connection leads 18 fixed to both sides of its surface. The connection leads 18 located on both sides of the holder cover 17 are connected to the first connection terminal 31c and the second connection terminal 32c of the first spring contact 31 and the second spring contact 32 on each battery holder 2. The surface of the holder cover 17 to which the connection leads 18 are fixed is oriented facing the bottom plate 23 of the battery holder 2, and is in contact with the first connection terminal 31c and the second connection terminal 32c protruding from the battery holder 2. The connection leads 18 of the holder cover 17 in Figure 8 connect the first spring contact 31 and the second spring contact 32 in parallel, connecting the battery cells 1 in parallel. The holder cover 17 in FIG. 9 connects the first spring contact 31 and second spring contact 32 of adjacent battery holders 2 in series with connection leads 18, connecting the battery cells 1 in series.

[0050] The first spring contact 31 and the second spring contact 32 are connected to connect the battery cells 1 in parallel and / or series. The battery holder 2 has the first spring contact 31 and the second spring contact 32 arranged on either side of the bottom surface of the bottom plate 23.

[0051] 9 shows that adjacent battery holders 2 alternately arrange the first connection terminals 31c of the first spring contacts 31 and the second connection terminals 32c of the second spring contacts 32. The holder cover 17 has connection leads 18 arranged along both side edges that connect adjacent second connection terminals 32c in series. The connection leads 18 arranged on the side edges of the holder cover 17 connect the second connection terminals 32c of adjacent battery holders 2, connecting each battery cell 1 in series.

[0052] As shown in Figures 8 and 9, in a battery pack 10 in which a holder cover 17 is placed opposite the bottom plate 23 of the battery holder 2, the battery cells 1 can be connected in parallel or in series by changing the connection leads 18 on the holder cover 17. As shown in Figure 1, in a battery block 11, output terminals are provided on each battery pack 10, and battery packs 10 can be connected in series and / or in parallel using connection leads 18 connected to these output terminals. Connection leads 18 that connect adjacent battery packs 10 in series or in parallel can be provided on the circuit board 7. Alternatively, connection leads 18 can be provided external to the circuit board 7 to connect adjacent battery packs 10 in series or in parallel.

[0053] 1, the bottom surfaces of the metal tubes 15 of the battery cells 1 arranged in parallel are arranged on the same plane, so a cooling plate can be placed in thermal contact with the bottom surface of the metal tubes 15. The power supply unit 100 with this structure has the advantage that the cooling plate can dissipate heat evenly and efficiently from each battery cell 1.

[0054] Furthermore, as shown in the cross-sectional schematic diagram of FIG. 10 , the power supply unit 100 can be provided with a sub-battery holder 26 into which the second end face 1b of the battery cell 1 opposite the end face electrode 13a (the bottom of the metal tube 15 of the battery cell 1 in the figure) is inserted to position the second end face 1b of the battery cell 1 in a fixed position. The sub-battery holder 26 has a sub-detachable recess 27 into which the bottom of the metal tube 15 can be detachably inserted. For each battery cell 1, one end (first end face 1a) on the end face electrode 13a side is inserted into the detachable recess 20 of the battery holder 2, and the other end (second end face 1b) opposite the end face electrode 13a is inserted into the sub-detachable recess 27, so that the battery cell 1 can be clamped and held in a fixed position by both the battery holder 2 and the sub-battery holder 26. The sub-battery holder 26 is placed on the inner surface of the exterior case 6, allowing the bottom of the metal tube 15 to be positioned in a fixed position.

[0055] The multiple battery cells 1 are electrically connected via the spring contacts 3 and connection leads 18. The spring contacts 3 are connected to the connection leads 18 shown in the exploded perspective views of Figures 8 and 9. The connection leads 18 are connected to the connection terminals of the spring contacts 3 (first connection terminal 31c, second connection terminal 32c) and connect the multiple battery cells 1 in series or parallel. The connection leads 18 in Figures 8 and 9 are fixed to the surface of a holder cover 17 that is located on the outer surface of the bottom plate 23 of the battery holder 2. The holder cover 17 is located on the outer surface of the bottom plate 23 of the battery holder 2 and connects the battery cells 1 in series or parallel.

[0056] The power supply unit 100 in Figure 1 has a circuit board 7 mounted on the surface of the holder cover 17. The circuit board 7 is equipped with a protection circuit (not shown) that controls the charging and discharging of the battery cells 1. The protection circuit is connected to a temperature sensor that detects the voltage and current of the battery cells 1 as well as the temperature of the battery cells 1, and controls the charging and discharging of the battery cells 1 to maintain the power supply unit 100 in a safe operating state. The circuit board 7 is connected to the battery cells 1 via the connection leads 18 and spring contacts 3, and is able to detect the voltage and current of the battery cells 1.

[0057] The power supply unit of the present disclosure can be effectively used as a power supply unit with a reusable structure in which non-standard battery cells can be simply and easily removed and replaced.

[0058] REFERENCE SIGNS LIST 100...power supply unit 1...battery cell 1a...first end face 1b...second end face 1A...cylindrical battery 2...battery holder 3...spring contact 6...external case 6A...lower case 6B...top cover 7...circuit board 10...assembled battery 11...battery block 12...electrode 12a...first electrode 12b...second electrode 13a...end face electrode 13b...surface electrode 14...sealing plate 14a...valve opening mechanism 15...metal tube 16...peripheral groove 17...holder cover 18...connection lead 20...detachment recess 21...engagement claw 21a...elastic arm 21b...locking protrusion 22...discharge opening 23...bottom plate 24...retaining wall 25a...hole 25b...hole 26...sub-battery holder 27...sub-detachment recess 31...first spring contact 31a...first mounting portion 31b...first contact portion 31c...first connection terminal 32...second spring contact 32a...second mounting portion 32b...second contact portion 32c...second connection terminal

Claims

1. A battery holder comprising: a plurality of battery cells each having an outer circumferential groove on one end side; a battery holder made of insulating material in which the battery cells are arranged in fixed positions; and spring contacts which are elastically pressed against and electrically connected to the positive and negative electrodes of the battery cells, the positive and negative electrodes being provided on the battery cells, one of the positive and negative electrodes being a first electrode and the other of the positive and negative electrodes being a second electrode, the first electrode being an end surface electrode provided on an end surface of the battery cell, the spring contacts comprising: a first spring contact electrically connected to the end surface electrode which is the first electrode of the battery cell; and a second spring contact electrically connected to the second electrode of the battery cell, the battery holder comprising: attachment / detachment recesses into which ends of each of the battery cells are inserted in a removable state; and fitting claws which are guided by the outer circumferential groove of the battery cell which is guided into the attachment / detachment recesses and which engage the battery cells in a removable state, the first spring contacts being a battery holder that is disposed in a center portion of a bottom surface of the attachment / detachment recess and is electrically connected to the end surface electrode that is the first electrode of the battery cell inserted into the attachment / detachment recess, and the battery holder engages the fitting claws with the outer peripheral groove to position the battery cell in a fixed position in the attachment / detachment recess in a state that allows the battery cell to be removed.

2. A power supply unit as claimed in claim 1, wherein the second spring contact is arranged to protrude elastically from the inner surface of the attachment / detachment recess and is elastically pressed against the second electrode to electrically connect the battery cell, allowing replacement of the battery cell.

3. A power supply unit as claimed in claim 1, wherein the engaging tabs of the battery holder themselves are elastically deformed to engage the battery cells in the attachment / detachment recesses in a state in which they can be removed, thereby enabling replacement of the battery cells.

4. A power supply unit as claimed in claim 1, comprising an outer case housing a plurality of said battery cells, said outer case having a battery block having a plurality of said battery cells disposed therein, said battery block having a plurality of assembled batteries, said assembled batteries being formed by connecting a plurality of said battery cells in an integral structure, said power supply unit enabling the replacement of battery cells.

5. A power supply unit according to claim 1, wherein the battery cells are cylindrical batteries and the battery cells can be replaced.

6. A power supply unit as described in claim 4, wherein the battery pack comprises a holder cover having a plurality of the battery holders arranged and connected on its surface, the holder cover having connection leads on its surface, the connection leads being connected to the spring contacts which are connected to the adjacent battery holders, and the adjacent battery cells are connected at least in series or parallel, making the power supply unit battery cell replaceable.

7. A power supply unit as described in claim 1, comprising a sub-battery holder into which ends of the battery cells are inserted to position adjacent battery cells in fixed positions, the sub-battery holder having a sub-detachable recess into which the ends of the battery cells are inserted so as to be freely detachable, one end of a plurality of battery cells is inserted into the detachable recess and the other end of the battery cell is inserted into the sub-detachable recess, and the battery cells are arranged in parallel at fixed positions in this power supply unit, allowing the replacement of battery cells.

8. A power supply unit as claimed in claim 1, which allows the battery cell to be replaced and which includes a circuit board on which a protection circuit is mounted that is electrically connected to the first electrode and the second electrode of the battery cell via the first spring contact and the second spring contact.

9. A power supply unit as claimed in any one of claims 1 to 8, wherein the battery cell is provided with a valve opening mechanism which opens and ejects waste materials when the internal pressure exceeds a set pressure, and the battery holder is connected to the inside and outside of the attachment / detachment recess, and has an exhaust opening which allows the passage of waste materials ejected from the valve opening mechanism, allowing the battery cell to be replaced.

10. A power supply unit comprising: a plurality of battery cells; and a battery holder made of an insulating material in which each of the battery cells is arranged in a fixed position, wherein the battery cell has: a first electrode and a second electrode provided on an end face of the battery cell; and an outer circumferential groove recessed toward the center along the outer periphery near one end of the battery cell, and the battery holder has: a first spring contact arranged in the center of the bottom surface of the attachment / detachment recess; a second spring contact; a attachment / detachment recess into which the one end of the battery cell is inserted; and a fitting claw facing the outer circumferential groove, wherein the first spring contact is elastically pressed against the first electrode to be electrically connected, and the second spring contact is elastically pressed against the second electrode to be electrically connected, and the fitting claw deforms outward from the battery holder and is guided into the outer circumferential groove to engage.

11. The power supply unit according to claim 10, wherein the second spring contact is disposed protruding from the inner surface of the attachment / detachment recess and is elastically pressed against the second electrode to be electrically connected thereto.

12. The power supply unit according to claim 10, wherein the engaging claws themselves are elastically deformed to engage with the outer circumferential groove.

13. A power supply unit as described in claim 10, comprising an exterior case, the exterior case having a battery block disposed therein, the battery block having a plurality of assembled batteries via a plurality of battery holders, each of the plurality of assembled batteries connecting a plurality of the battery cells in an integral structure.

14. The power supply unit according to claim 10, wherein the battery cells are cylindrical batteries.

15. A power supply unit as described in claim 13, further comprising a holder cover which connects to the plurality of battery cells via the battery holder, the holder cover having connection leads on its surface, the connection leads being connected to adjacently arranged first spring contacts or adjacently arranged second spring contacts, thereby connecting the adjacently arranged plurality of battery cells at least in series or parallel.

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