Anticorrosion battery pack housing

Abstract

The present invention provides a structure of an electrodeposition-coated battery pack housing, the structure comprising: a body part; a bracket provided on the surface of the body part; welding parts in which the body part and the bracket are spot-welded to each other; and a water-sealing material interposed between the body part and the bracket, wherein the water-sealing material is provided in waterproof regions each formed in a closed-loop shape so as to overlap the perimeter of a predetermined adjacent region in which the body part and the bracket are adjacent to each other.

Description

Corrosion-resistant battery pack housing

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0175526 filed on November 29, 2024, and all contents disclosed in the document of said Korean patent application are incorporated herein as part of this specification.

[0002] The present invention relates to a corrosion-resistant housing structure as a housing constituting the exterior of a battery pack.

[0003] Secondary batteries, which offer high applicability across product lines and possess electrical characteristics such as high energy density, are widely applied not only to portable devices but also to electric vehicles (EVs) or hybrid electric vehicles (HEVs) powered by electric driving sources.

[0004] These secondary batteries are attracting attention as a new energy source for improving eco-friendliness and energy efficiency, as they not only have the primary advantage of being able to drastically reduce the use of fossil fuels but also the advantage of not generating any by-products from the use of energy.

[0005] Currently, widely used types of secondary batteries include lithium-ion batteries, lithium-polymer batteries, nickel-cadmium batteries, nickel-hydrogen batteries, and nickel-zinc batteries. The operating voltage of these individual secondary battery cells is approximately 2.5V to 4.5V. Therefore, if a higher output voltage is required, multiple battery cells are connected in series to form a battery pack. Additionally, depending on the charge / discharge capacity required for the battery pack, multiple battery cells are connected in parallel to form a battery pack. Accordingly, the number of battery cells included in the battery pack and the electrical connection type can be set in various ways depending on the required output voltage and / or charge / discharge capacity.

[0006] A battery pack generally consists of multiple battery cells or modules and a pack housing that accommodates them. While the structure and specific materials may vary, the pack housing is often manufactured by sheet metal processing of lightweight metals, such as aluminum, and assembling these processed sheets by joining or fastening them together.

[0007] For example, FIG. 1 shows a battery pack housing comprising a main body (1) made of metal and a bracket (2) made of metal mounted on the main body (1). Here, the bracket (2) is welded so that one side of it faces one side of the main body (1). Since the main body (1) and the bracket (2) must come into contact with each other over a large area, they are spot welded at a plurality of predetermined welds (3) to ensure economic efficiency. Accordingly, one side of the main body (1) and one side of the bracket (2) are adjacent or in close contact with each other in a face-to-face state.

[0008] The above housing is electrodeposited after welding the main body (1) and the bracket (2) to prevent water damage and corrosion. Electrodepositing is a technique of immersing a workpiece in an electrodepositing paint. While this electrodepositing method has the advantage of allowing the paint to penetrate evenly into corners that are difficult to access from the outside, it has the problem that it is difficult to penetrate into narrow spaces between adjacent or closely spaced members, such as the bracket (2) and the main body (1).

[0009] Referring to FIG. 2, the electrodeposition paint cannot penetrate the narrow space where the main body (1) and the bracket (2) are adjacent to each other, resulting in an uncoated area. If moisture or humidity penetrates the uncoated area, corrosion (C) may occur in the uncoated area. Since such corrosion is difficult to detect from the outside and difficult to prevent through electrodeposition coating in the first place, it has a significant negative impact on the structural and chemical stability of the battery pack housing.

[0010] The present invention was conceived against the background of the prior art described above, and aims to provide a structure of a battery pack housing in which corrosion is prevented between the main body and the bracket in a battery pack housing in which the bracket is spot-welded adjacent to the main body.

[0011] Specifically, the present invention aims to provide a structure for a pack housing in which corrosion does not occur in the adjacent area between the main body and the bracket, where electrodeposition coating is impossible.

[0012] The technical problems of the present invention are not limited to the purposes mentioned above, and other unmentioned purposes and advantages of the present invention may be understood from the following description and will be more clearly understood by the embodiments of the present invention. Furthermore, it will be readily apparent that the purposes and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims.

[0013] To solve the above problem, the present invention provides a structure of a battery pack housing comprising: a main body; a bracket installed on the surface of the main body; a welded portion in which the main body and the bracket are spot-welded to each other; and a watertight material interposed between the main body and the bracket.

[0014] The battery pack housing described above may be electrodeposited with the main body and the bracket welded to each other. As the electrodepositing is performed, all non-facing surfaces of the main body and the bracket are coated. At this time, some areas where the main body and the bracket face each other may remain uncoated as the electrodeposited paint cannot penetrate them. Such uncoated areas do not necessarily correspond to adjacent areas described later.

[0015] According to the present invention, a predetermined adjacent area is defined where the main body and the bracket are adjacent to each other, and the watertight material is provided in a waterproof area formed in the shape of a closed curve so as to overlap with the perimeter of the adjacent area.

[0016] The above watertight material may include a sealant in the form of a high-viscosity liquid or semi-solid formulation. In this case, the watertight material may be interposed between the main body and the bracket as the main body and the bracket are welded together while being applied to the surface of the main body and / or the bracket.

[0017] Alternatively, the watertight material may include a compressible material. In this case, the watertight material may be compressed between the main body and the bracket as the main body and the bracket are welded together.

[0018] Of course, the above-mentioned watertight material can be anything different from the examples above, regardless of its material or shape, as long as it is interposed between any two members to increase the watertightness between the two members.

[0019] It is preferable that the above adjacent area be defined such that, after the electrodeposition coating, the entire corrosive surface of the housing is protected from corrosion by the electrodeposition coating or the watertight material, taking into account various factors such as the range in which the electrodeposition paint can penetrate during the electrodeposition coating, the viscosity or strength after curing of the electrodeposition paint, the distance between the main body and the bracket after welding, and the method of performing the spot welding method.

[0020] For example, the above adjacent area may be defined as an unpainted area between the main body and the bracket when the main body and the bracket are welded together without the interposition of the watertight material and then electroplated.

[0021] For example, the aforementioned adjacent area may be established by experimental methods, such as measuring the uncoated area by electrodepositing a housing that is not actually provided with the watertight material, or by intentionally exposing the electrodeposited housing to an environment where corrosion may occur to measure the corroded area. Alternatively, the aforementioned adjacent area may be established by theoretical methods, such as calculating or modeling the range in which the electrodeposited paint can penetrate during electrodeposition.

[0022] Within the aforementioned adjacent area, the mutually facing surfaces of the main body and the bracket may be substantially parallel to each other. That is, the adjacent area may be an area where the distance between the main body and the bracket corresponds to a predetermined distance.

[0023] The above predetermined distance may be greater than the distance between the main body and the bracket at the weld or in the vicinity thereof (e.g., a point within 1 mm from the weld), which can be described as the closest distance between the main body and the bracket.

[0024] The above adjacent area may be defined as an area where the distance between the main body and the bracket is less than or equal to a predetermined distance.

[0025] In this case, the criterion for determining the above predetermined distance may be related to the maximum distance that prevents the electroplated paint from penetrating between the main body and the bracket, or the maximum distance at which watertightness can be ensured using the watertight material.

[0026] For example, the thickness of the watertight material may correspond to the predetermined distance. If the watertight material is a compressible material, the thickness of the watertight material before compression may be greater than or equal to the predetermined distance.

[0027] It is preferable that the above adjacent area includes the part where the weld is formed. This is because the distance between the main body and the bracket is likely to be shortest at the weld.

[0028] At this time, it is preferable that the minimum gap between the perimeter of the adjacent area and the weld be set to a predetermined size or larger. Accordingly, heat generated during the welding process can be prevented from affecting the watertight material. For example, if the watertight material is a compressible thermoplastic synthetic resin, heat generated from the weld may melt the watertight material. Alternatively, if the watertight material is a liquid sealant, heat generated from the weld may vaporize or burn the watertight material.

[0029] According to one embodiment, it is preferable that the predetermined gap be set to 5 mm or more. When the predetermined gap is less than 5 mm, there is a high risk that the watertight material will be deformed or damaged by welding heat.

[0030] The above-mentioned adjacent area may have an outer perimeter. In other words, the perimeter of the above-mentioned adjacent area may include an outer perimeter. In this case, the waterproof area may be formed along the outer perimeter of the above-mentioned adjacent area. More specifically, the waterproof area may overlap with the outer perimeter of the above-mentioned adjacent area in the thickness direction, or its outer perimeter or inner perimeter may be formed to correspond to the outer perimeter of the above-mentioned adjacent area.

[0031] The main body may have a hole within an area overlapping with the bracket. One or more holes may be provided. Accordingly, the adjacent area may have one or more inner circumferences. In this case, the waterproof area may be formed along the outer and inner circumferences of the adjacent area. More specifically, the waterproof area may overlap with the inner circumference of the adjacent area in the thickness direction, or its outer or inner circumference may be formed to correspond to the inner circumference of the adjacent area.

[0032] It is preferable that the above waterproof area be formed to correspond to the entire perimeter of the adjacent area. This completely blocks the path of water penetration into the adjacent area, thereby preventing corrosion of the adjacent area.

[0033] According to one embodiment, the adjacent area has one outer circumference and two inner circumferences, and the waterproof area can be formed with a total of three closed curve shapes corresponding thereto, and the closed curve corresponding to the outer circumference of the adjacent area among the waterproof areas can be formed such that its outer circumference corresponds to the outer circumference of the adjacent area, and the closed curves corresponding to the inner circumference of the adjacent area can be formed such that their inner circumference corresponds to the inner circumference of the adjacent area.

[0034] The present invention can provide a structure for a battery pack housing that prevents corrosion in areas where electroplating is impossible by ensuring watertightness in the adjacent area between the main body and the bracket.

[0035] Another advantage of the present invention is that it can provide a structure for a pack housing that is unaffected by welding heat, prevents corrosion in all parts including areas where the electrodeposited paint cannot penetrate, and effectively prevents corrosion even when a hole is provided in the main body.

[0036] The present invention can also provide an economical and effective arrangement of watertight materials by specifying a method of defining adjacent areas.

[0037] In addition to the above, the present invention may have various other effects, which are described in each embodiment, or effects that can be easily inferred by a person skilled in the art, etc., will be omitted.

[0038] Figure 1 shows a housing with a bracket mounted thereon.

[0039] Figure 2 shows corrosion occurring in the housing of Figure 1.

[0040] FIG. 3 shows the main body and bracket of a housing according to one embodiment.

[0041] FIG. 4 shows an adjacent area of ​​the main body and the bracket according to one embodiment.

[0042] FIG. 5 is a schematic diagram illustrating a method for defining an adjacent area according to one embodiment and another embodiment.

[0043] FIG. 6 shows the arrangement of adjacent areas for a welded portion according to one embodiment.

[0044] FIG. 7 shows the perimeter of an adjacent area according to one embodiment.

[0045] FIG. 8 shows a housing in which a watertight material is applied to a waterproof area according to one embodiment.

[0046] [Explanation of the symbol]

[0047] 1: Main body 10: Hole 2: Bracket 3: Weld 4: Watertight material A: Adjacent area A1: Adjacent area A2: Adjacent area B: Waterproof area C: Corrosion D: Perimeter Do: Outer circumference Di: Inner circumference P1: Planar P2: Planar G: Minimum clearance

[0048] The aforementioned objectives, features, and advantages are described in detail below with reference to the attached drawings, thereby enabling those skilled in the art to easily implement the technical concept of the present invention. In describing the present invention, detailed descriptions of known technologies related to the present invention are omitted if it is determined that such descriptions would unnecessarily obscure the essence of the invention. Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the attached drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

[0049] Although terms such as "first," "second," etc., are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless specifically stated otherwise, the first component may also be the second component.

[0050] Throughout the specification, unless specifically stated otherwise, each component may be singular or plural.

[0051] In the following, the statement that any configuration is placed on the "upper (or lower)" of a component or on the "upper (or lower)" of a component may mean not only that any configuration is placed in contact with the upper (or lower) surface of said component, but also that another configuration may be interposed between said component and any configuration placed on (or below) said component.

[0052] In addition, where it is stated that one component is "connected," "combined," or "connected" to another component, it should be understood that while the components may be directly connected or connected to each other, another component may be "interposed" between each component, or each component may be "connected," "combined," or "connected" through another component.

[0053] Singular expressions used in this specification include plural expressions unless the context clearly indicates otherwise. In this application, terms such as "composed of" or "comprising" should not be interpreted as necessarily including all of the various components or steps described in the specification, and should be interpreted as meaning that some of the components or steps may be omitted or additional components or steps may be included.

[0054] Throughout the specification, "A and / or B" means A, B, or A and B unless specifically stated otherwise, and "C to D" means C or more and D or less unless specifically stated otherwise.

[0055] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

[0056] FIG. 3 shows a main body and a bracket of a housing according to one embodiment. Referring thereto, a battery pack housing according to one embodiment of the present invention includes a main body (1) and a bracket (2) installed on the surface of the main body (1).

[0057] The above main body (1) may be configured in a shell shape comprising a metal, mainly aluminum, that constitutes at least a portion of the receiving space in which a battery module and / or battery cell is received. However, the essence of the present invention is unrelated to the specific shape of the above main body (1).

[0058] The above bracket (2) is also made of metal material, preferably including the same type of metal material as the main body (1), and may be mounted to fix the main body (1) to an external device, but there is no problem even if its specific shape and function are different from this.

[0059] The main body (1) may have a hole (10) in particular within an area that overlaps with the bracket (2) in the thickness direction. Multiple holes (10) may be provided. The function and specific shape of the hole (10) may vary, but the present invention does not specify the specific function and shape of the hole (10).

[0060] FIG. 4 shows an adjacent area of ​​a main body and a bracket according to one embodiment. Referring thereto, the main body (1) and the bracket (2) are spot welded to each other at a predetermined weldment (3). A plurality of weldments (3) are provided so that the bracket (2) can be mounted at a predetermined position on the surface of the main body (1). The spot welding may be performed by resistance welding, but is not necessarily limited to this method. However, regardless of the method, it is common for high welding heat to be generated at the weldment (3) during the spot welding process.

[0061] The above battery pack housing can be electrodeposited with the main body (1) and the bracket (2) welded together. As the electrodeposited coating is performed, all parts of the surfaces of the main body (1) and the bracket (2) that do not face each other are coated. At this time, due to the characteristics of spot welding, the main body (1) and the bracket (2) become adjacent to each other not only at the welded part (3) but also in a predetermined area surrounding the welded part (3), and the predetermined area may remain uncoated as the electrodeposited paint cannot penetrate it. The uncoated area described above does not necessarily correspond to the adjacent area described later.

[0062] According to the present invention, a predetermined adjacent area (A) is defined where the main body (1) and the bracket (2) are adjacent to each other. Briefly speaking, the adjacent area (A) is an area where the main body (1) and the bracket (2) are adjacent to each other, making it difficult for the electrodeposited paint to penetrate, yet there is a risk of water or air penetrating, which can be described as an area with a high risk of corrosion. In addition to this risk, the adjacent area (A) can be determined by considering various design factors.

[0063] FIG. 5 is a schematic diagram illustrating a method for defining adjacent areas according to one embodiment and another embodiment. Referring thereto, the battery pack housing according to one embodiment of the present invention includes a watertight material (4) interposed between the main body part (1) and the bracket (2).

[0064] The above watertight material (4) is provided in a waterproof area (B) formed in a closed curve shape so as to overlap with the perimeter (D) of the adjacent area (A). By doing so, the watertight material (4) prevents the penetration of water or air into the adjacent area (A), thereby preventing corrosion even though the adjacent area (A) is not painted.

[0065] The above watertight material (4) may include a sealant in the form of a high-viscosity liquid or semi-solid formulation. In this case, the watertight material (4) may be applied to the surface of the main body (1) and / or the bracket (2) and interposed between the main body (1) and the bracket (2) as the main body (1) and the bracket (2) are welded together.

[0066] Alternatively, the watertight material (4) may include a compressible material. In this case, the watertight material (4) may be compressed between the main body (1) and the bracket (2) as the main body (1) and the bracket (2) are welded together.

[0067] Of course, the above watertight material (4) can be anything different from the examples above, regardless of its material or shape, as long as it is interposed between any two members to increase the watertightness between the two members.

[0068] As described above, the adjacent area (A) can be defined in various ways. Specifically, the adjacent area (A) is preferably defined such that, after the electrodeposition coating, the entire corrosive surface of the housing is protected from corrosion by the electrodeposition coating or the watertight material (4), by taking into account various factors such as the range in which the electrodeposition paint can penetrate during the electrodeposition coating, the viscosity of the electrodeposition paint or the strength after curing, the distance between the main body (1) and the bracket (2) after welding, and the method of performing the spot welding method.

[0069] For example, the adjacent area (A) may be defined as an unpainted area between the main body (1) and the bracket (2) when the main body (1) and the bracket (2) are welded together without the watertight material (4) and then electroplated.

[0070] For example, the above adjacent area (A) may be established by experimental methods, such as measuring the uncoated area by electrodepositing a housing in which the watertight material (4) is not actually provided, or by intentionally exposing the electrodeposited housing to an environment where corrosion may occur to measure the corroded area. Alternatively, the above adjacent area (A) may be established by theoretical methods, such as calculating or modeling the range in which the electrodeposited paint can penetrate during electrodeposition.

[0071] According to one embodiment, the adjacent area (A1) may be an area where the distance between the main body (1) and the bracket (2) corresponds to a predetermined distance. In other words, within the adjacent area (A1), the mutually facing surfaces of the main body (1) and the bracket (2) may be substantially parallel to each other. In this case, for example, assuming that the main body (1) is completely flat in the area overlapping with the bracket (2), the perimeter of the adjacent area (A1) may be defined as one or more closed curves where a virtual plane (P1) located at the predetermined distance from the bracket (2) and the main body (1) meets.

[0072] In other embodiments, the adjacent area (A2) may be set larger than the adjacent area (A1) according to the first embodiment, taking into account the thickness of the watertight material (4), etc. For example, the adjacent area (A2) may be defined as an area where the distance between the main body (1) and the bracket (2) is less than or equal to a predetermined distance. In this case, for example, assuming that the main body (1) is completely flat in the area overlapping with the bracket (2), the perimeter of the adjacent area (A1) may be defined as one or more closed curves where a virtual plane (P2) located at the predetermined distance from the bracket (2) and the main body (1) meets.

[0073] In this case, the criteria for determining the above predetermined distance may be related to the maximum distance that prevents the electroplated paint from penetrating between the main body (1) and the bracket (2), or the maximum distance at which watertightness can be ensured using the watertight material (4).

[0074] For example, the thickness of the watertight material (4) may correspond to the predetermined distance. If the watertight material (4) is a compressible material, the thickness of the watertight material (4) before compression may be greater than the predetermined distance.

[0075] FIG. 6 shows the arrangement of adjacent regions for a welded portion according to one embodiment. Referring thereto, it is preferable that the adjacent region (A) includes the area where the welded portion (3) is formed. This is because the distance between the main body (1) and the bracket (2) is likely to be shortest at the welded portion (3).

[0076] At this time, it is preferable that the minimum gap (G) between the perimeter (D) of the adjacent area (A) and the weld (3) be set to a predetermined size or larger. Accordingly, heat generated during the welding process can be prevented from affecting the watertight material (4). For example, if the watertight material (4) is a compressible thermoplastic synthetic resin material, the heat generated from the weld (3) can melt the watertight material (4). Alternatively, if the watertight material (4) is a liquid sealant, the heat generated from the weld (3) can vaporize or burn the watertight material (4).

[0077] According to one embodiment, it is preferable that the predetermined gap be set to 5 mm or more. When the predetermined gap is less than 5 mm, there is a high risk that the watertight material (4) will be deformed or damaged by welding heat.

[0078] FIG. 7 shows the perimeter of an adjacent area according to one embodiment, and FIG. 8 shows a housing in which a watertight material is applied to a waterproof area according to one embodiment. Referring to these drawings, the adjacent area (A) may have an outer circumference (Do). In other words, the perimeter (D) of the adjacent area (A) may include the outer circumference (Do). At this time, the waterproof area (B) may be formed along the outer circumference (Do) of the adjacent area (A). More specifically, the waterproof area (B) may overlap with the outer circumference (Do) of the adjacent area (A) in the thickness direction, or may be formed such that its outer circumference or inner circumference corresponds to the outer circumference (Do) of the adjacent area (A).

[0079] The main body (1) may have a hole (10) within an area overlapping with the bracket (2). One or more holes (10) may be provided. Accordingly, the adjacent area (A) may have one or more inner circumferences (Di). At this time, the waterproof area (B) may be formed along the outer circumference (Do) and inner circumference (Di) of the adjacent area (A). More specifically, the waterproof area (B) may overlap with the inner circumference (Di) of the adjacent area (A) in the thickness direction, or its outer circumference or inner circumference may be formed to correspond to the inner circumference (Di) of the adjacent area (A).

[0080] It is preferable that the waterproof area (B) be formed to correspond to all the perimeter (D) of the adjacent area (A). This completely blocks the path of water penetration into the adjacent area (A), thereby preventing corrosion of the adjacent area (A).

[0081] According to one embodiment, the adjacent region (A) has one outer circumference (Do) and two inner circumferences (Di), and the waterproof region (B) may be formed with a total of three closed curve shapes corresponding thereto, and the closed curve corresponding to the outer circumference (Do) of the adjacent region (A) among the waterproof region (B) may be formed such that its outer circumference corresponds to the outer circumference (Do) of the adjacent region (A), and the closed curves corresponding to the inner circumference (Di) of the adjacent region (A) may be formed such that their inner circumference corresponds to the inner circumference (Di) of the adjacent region (A).

[0082] The embodiments described above should be understood as exemplary in all respects and not limiting, and the scope of the invention will be defined by the claims set forth below rather than by the detailed description above. Furthermore, the meaning and scope of the claims set forth below, as well as all modifications and variations derived from equivalents thereof, should be interpreted as being included within the scope of the invention.

[0083] Although the present invention has been described above with reference to the illustrated drawings, the present invention is not limited by the embodiments and drawings disclosed in this specification, and it is obvious that various modifications can be made by a person skilled in the art within the scope of the technical concept of the present invention. Furthermore, even if the effects of the configuration according to the present invention were not explicitly described while describing the embodiments of the present invention above, it is natural to acknowledge that the effects predictable by said configuration should also be recognized.

Claims

1. Main body; A bracket installed on the surface of the main body part; A welded portion in which the main body and the bracket are spot-welded to each other; and A battery pack housing comprising: a watertight material interposed between the main body and the bracket; The above battery pack housing is electroplated with the main body and the bracket welded to each other, and A predetermined adjacent area is defined where the main body and the bracket are adjacent to each other, and The above watertight material is provided in a waterproof area formed in a closed curve shape so as to overlap with the perimeter of the adjacent area, in a battery pack housing.

2. A battery pack housing according to claim 1, wherein the watertight material comprises a sealant in the form of a high-viscosity liquid or semi-solid formulation.

3. A battery pack housing according to claim 1, wherein the watertight material comprises a compressible material.

4. A battery pack housing according to claim 1, wherein the adjacent area is defined as an unpainted area between the main body and the bracket when the main body and the bracket are welded together without the interposition of the watertight material and then electroplated.

5. A battery pack housing according to claim 1, wherein the mutually facing surfaces of the main body and the bracket within the adjacent area are substantially parallel to each other.

6. A battery pack housing according to claim 1, wherein the adjacent area is defined as an area where the distance between the main body and the bracket is less than or equal to a predetermined distance.

7. A battery pack housing according to claim 6, wherein the predetermined distance is greater than or equal to the distance between the main body and the bracket at the welded part or at a point within 1 mm from thereto.

8. A battery pack housing according to claim 1, wherein the thickness of the watertight material corresponds to the predetermined distance.

9. A battery pack housing according to claim 1, wherein the adjacent region includes the portion where the weld is formed.

10. A battery pack housing according to claim 9, wherein the minimum gap between the perimeter of the adjacent area and the weld is set to be greater than or equal to a predetermined value.

11. A battery pack housing according to claim 10, wherein the predetermined gap is set to 5 mm or more.

12. In claim 1, the adjacent area has an outer perimeter, The above waterproof area is a battery pack housing formed along the outer periphery of the above adjacent area.

13. In claim 1, the main body portion has a hole within an area overlapping with the bracket, and Accordingly, the above adjacent area has an inner circumference, The above waterproof area is formed along the outer and inner periphery of the above adjacent area, a battery pack housing.

14. In claim 13, the main body portion has a plurality of holes, and Accordingly, the above adjacent area is a battery pack housing having a plurality of inner circumferences.

15. A battery pack housing according to claim 1, wherein the waterproof area is formed to correspond to all perimeters of the adjacent area.

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