Battery post welding

Abstract

An apparatus arranged for establishing an electrical connection to battery cells is described. The apparatus includes a bushing, a post, and a weld. The bushing has a bushing first portion and a bushing second portion. The post is in physical contact with the bushing. The weld is welded using laser welding and includes bushing material and post material. A weld first portion extends away at least from the bushing. A weld second portion is contiguous to the weld first portion, within the bushing, and over the post. A weld third portion is contiguous to the weld second portion, within the bushing, and surrounding the post. The weld has a first depth measured from the bushing first portion and / or a second depth measured from the bushing second portion. The first depth and / or the second depth meet or exceed a depth minimum threshold.

Description

[0001] BATTERY POST WELDING

[0002] TECHNICAL FIELD

[0003] This disclosure relates to a method for making and an apparatus including battery cell connections, such as welds.

[0004] BACKGROUND

[0005] As battery technology evolves, the demand for improved power sources such as energy storage modules for vehicles continues to grow. Existing battery systems, for example lead acid battery systems, typically offer limited access to performance and failure monitoring. More specifically, existing lead acid battery systems may not be capable of providing one or more battery parameters (e.g., usable to determine performance and / or predict / monitor failure) of one or more battery cells of the lead acid battery system. In other words, it is difficult for existing lead acid battery systems to provide information about vital components, such as the state of health of the individual battery cells. Accordingly, the state of health of battery cells cannot be monitored and / or determined, thus hindering the ability to predict upcoming battery failure or the onset of failure.

[0006] Further, some batteries may have battery cells with a battery cell connection. The battery cell connection may be referred to as a weld and provide an electrical connection to the battery cell for measuring a battery parameter such as battery cell voltage. The weld is typically formed and sealed to the battery cover using tungsten inert gas (TIG) welding. TIG welding may also be referred to as gas tungsten arc welding (GT AW) and may use a tungsten electrode that produces a welding arc. The inert gas is used to cool the tungsten and weld. However, in some cases, TIG welding does not provide consistent results. For example, the use of TIG welding to form the weld may result in poor sealing characteristics between the weld and the battery cover, poor weld characteristics, and damage to other battery components such as the cover.

[0007] SUMMARY

[0008] Some embodiments advantageously provide a battery cell connection (and / or method of making a battery cell connection) for sensing a parameter associated with a battery cell and / or a battery. In some embodiments, the connection is a weld formed between two or more battery components using a welding process such as laser welding. According to an aspect, an apparatus arranged for establishing an electrical connection to battery cells of a battery is described. The apparatus includes a bushing, a post, and a weld. The bushing includes a bushing material and has a bushing first portion and a bushing second portion. The post is in physical contact with the bushing and includes a post material. The weld is welded using laser welding and includes the bushing material and the post material. The weld includes a weld first portion, a weld second portion, and a weld third portion. The weld first portion extends away at least from the bushing. The weld second portion is contiguous to the weld first portion, within the bushing, and over the post. The weld third portion is contiguous to the weld second portion, within the bushing, and surrounding the post. The weld has one or both of a first depth measured from the bushing first portion and a second depth measured from the bushing second portion. One or both of the first depth and the second depth meet or exceed a depth minimum threshold.

[0009] According to another aspect, a battery includes a cover, a case, a bushing, a post, and a weld. The case is coupled to the cover, and the bushing is coupled to the cover. The bushing includes a bushing material and has a bushing first portion and a bushing second portion. The post is in physical contact with the bushing and comprising a post material. The weld is welded using laser welding. The weld is coupled to the cover and includes the bushing material and the post material. In addition, the weld includes a weld first portion, a weld second portion, and a weld third portion. The weld first portion extends away from the cover. The weld second portion is contiguous to the weld first portion, within the bushing, and over the post. The weld third portion is contiguous to the weld second portion, within the bushing, and surrounding the post. The weld has one or both of a first depth measured from the bushing first portion and a second depth measured from the bushing second portion, where one or both of the first depth and the second depth meets or exceeds a depth minimum threshold.

[0010] According to one aspect, a method of making a weld for establishing an electrical connection to battery cells of a battery is described. The battery has a post, a bushing, a case and a cover sealed to the case. The post is inserted through the bushing, and at least a portion of the bushing is in physical contact with the cover and the post. The bushing includes a bushing material and has a bushing first portion and a bushing second portion. The post includes a post material. The method includes directing a laser beam to one or more areas of a plurality of areas and one or more depths of a plurality of depths of one or both of the post and the bushing and forming a weld using the laser beam. The formed weld includes a weld first portion, a weld second portion, and a weld third portion. The weld first portion extends away at least from the bushing. The weld second portion is contiguous to the weld first portion, within the bushing, and over the post. The weld third portion is contiguous to the weld second portion, within the bushing, and surrounding the post. The weld has a first depth measured from the bushing first portion and / or a second depth measured from the bushing second portion. The first depth and / or the second depth meeting or exceeding a depth minimum threshold.

[0011] BRIEF DESCRIPTION OF THE DRAWINGS

[0012] A more complete understanding of embodiments described herein, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:

[0013] FIG. 1 shows an example battery and one or more components of the example battery according to the principles of the present disclosure;

[0014] FIG. 2 shows an example battery (e.g., exploded view) and one or more components of the example battery according to the principles of the present disclosure;

[0015] FIG. 3 shows an example case and cover comprising bushings according to the principles of the present disclosure;

[0016] FIG. 4 shows example first cover coupled to case according to the principles of the present disclosure;

[0017] FIG. 5 shows an example post and bushing according to the principles of the present disclosure;

[0018] FIG. 6 shows another example post and bushing according to the principles of the present disclosure;

[0019] FIG. 7 shows an example step of a laser welding process according to the principles of the present disclosure;

[0020] FIG. 8 shows example battery after the laser welding process is completed according to the principles of the present disclosure;

[0021] FIGS. 9 shows a view of an example weld of FIG. 8 according to the principles of the present disclosure;

[0022] FIG. 10 shows a cross-section view of the example weld of FIG. 9 according to the principles of the present disclosure; FIG. 11 shows a view of an example weld shown in FIG. 8 according to the principles of the present disclosure;

[0023] FIG. 12 shows a cross-section view of the example weld of FIG. 11 according to the principles of the present disclosure;

[0024] FIG. 13 shows a cross-section view of an example weld according to the principles of the present disclosure;

[0025] FIG. 14 shows a section of the cross-section view of FIG. 13;

[0026] FIG. 15 shows another section of the cross-section view of FIG. 13;

[0027] FIG. 16 shows a flow chart of an example method of making a battery cell connection (weld) according to the principles of the present disclosure; and

[0028] FIG. 17 shows a flow chart of another example method of making a battery cell connection (weld) according to the principles of the present disclosure.

[0029] DETAILED DESCRIPTION

[0030] Before describing in detail exemplary embodiments, it is noted that the embodiments reside primarily in combinations of apparatus components and processing steps related to provide a connection (and / or method of making a connection) for sensing a parameter associated with a battery cell and / or a battery. Accordingly, the system and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present disclosure so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.

[0031] As used herein, relational terms, such as “first” and “second,” “top” and “bottom,” and the like, may be used solely to distinguish one entity or element from another entity or element without necessarily requiring or implying any physical or logical relationship or order between such entities or elements. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the concepts described herein. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and / or “including” when used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0032] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0033] In embodiments described herein, the joining term, “in communication with” and the like, may be used to indicate electrical or data communication, which may be accomplished by physical contact, induction, electromagnetic radiation, radio signaling, infrared signaling or optical signaling, for example. One having ordinary skill in the art will appreciate that multiple components may interoperate and modifications and variations are possible of achieving the electrical and data communication.

[0034] In some embodiments, the term “coupling” is used and may refer to a two or more components of a battery that are coupled to each other. A coupling may also include two or more components that are welded or coupled using any other coupling mechanism or process. In some other embodiments, a coupling may be referred to as a weld, such as the formed component that results from welding two or more components together. A weld may comprise at least a first portion and a second portion contiguous to the first portion. The first portion may be a top portion, and the second portion may be side portion. The first portion and / or the second portion may be referred to as a weld button and may extend another component such as a battery cover and be accessible and / or exposed such as to receive other components to which the weld button may be also coupled (welded). A weld may be referred to as a connection or battery cell connection.

[0035] FIGS. 1 and 2 show an example battery (e.g., a lead acid battery having a smart Absorbent Glass Mat (A GM) battery assembly) and one or more components of the example battery. Battery 10 may include at least one of the following: a case 12 (which may be made of from a resin or any other suitable material), one or more battery cells 14, a post assembly 15 (e.g., Cast-On-Strap (COS) post assembly), one or more straps 16, one or more posts 18 (e.g., a terminal post, a mini-post), a first cover 20, one or more bushings 22 (e.g., a U1 bushing, a mini-bushing), a lead assembly 24 (e.g., a lead frame), a battery management system (BMS) 26 (e.g., including a board), one or more fasteners 28, a second cover 30, a wiring harness 32, a vehicle connector 34, a third cover 36, and one or more terminal caps 38. Post assembly 15 may include the one or more straps 16 coupled to the one or more posts 18. In some embodiments, case 12 may be referred to as a housing.

[0036] FIG. 3 shows an example case 12 and first cover 20 comprising bushings 22 according to the principles of the present disclosure. More specifically, battery cells 14 (shown in FIG. 2) have been inserted in case 12. The battery cells 14 are connected to posts 18 (via post assembly 15 shown in FIG. 2). The first cover 20 comprises one or more bushings 22 such as bushing 22a (e.g., a mini-bushing) and bushing 22b and one or more terminal structures 23 that may be coupled to the first cover 20 and comprise a corresponding bushing 22 such as bushing 22a.Terminal structures 23 may be electrically coupled their corresponding terminal posts 25 which are arranged to couple to an electrical load and provide electrical energy to the electrical load, e.g., a vehicle system. Bushing 22a is aligned with post 18a, and bushing 22b is aligned with post 18b. Other bushings 22 may be aligned with other posts 18. The first cover 20 is then coupled (and / or sealed) to case 12.

[0037] FIG. 4 shows example first cover 20 coupled to case 12. More specifically, first cover 20 is shown coupled to case 12, where posts 18 may be in contact with their respective bushing 22, and at least a portion of post 18 protrudes from the respective bushing 22 as shown in FIGS. 5 and 6. On FIG. 5, post 18a has been inserted through bushing 22a, where post 18a may be in direct contact with bushing 22a, and a portion of post 18a protrudes from bushing 22a. On FIG. 6, post 18b has been inserted through bushing 22b, where post 18b may be in direct contact with bushing 22b, and a portion of post 18b protrudes from bushing 22b.

[0038] FIG. 7 shows an example step of a laser welding process. The laser welding process may be used to couple two or more components together. More specifically, head 40 is arranged to emit laser beam 42 and direct laser beam 42 in the direction of post 18 and bushing 22. Directing laser beam 42 is used to couple post 18 to bushing 22, i.e., to weld post 18 and bushing 22 together. Laser beam 42 provides a concentrated energy source, which allows controlling which area and / or depth of the post 18 and / or bushing 22 receives energy. The position of head 40 may be changed to change the angle of laser beam 42, thereby allowing laser beam 42 to deliver the concentrated energy source to different areas and depths in a controlled manner. That is, laser beam 42 of the laser welding process may be used for precision welding across one or mor axes and to achieve a predetermined "depth of bum" (DOB) without damaging battery components such as the battery cover and / or without compromising the coupling between the weld and the cover. Further, laser beam 42 of the laser welding process provides welding rates that are higher than conventional TIG welding and other conventional welding techniques. The laser welding process may be referred to as laser-deep-welding.

[0039] Conventional welding methods rely on heat-conductivity which may limit the ability to reach a predetermined DOB. The predetermined DOB may be required for reliable, leak-tight sealing of the weld (e.g., connection). If heat is applied to reach a sufficient DOB, the material (e.g., plastic) in which the bushing 22 is embedded absorbs some of the heat and may change its properties (e.g., may exhibit plastic properties, plastify, become plastic or malleable, etc.), thereby causing bushing 22 to lose its position, create a leak-path, or migrate into the weld- zone.

[0040] In some embodiments, using the laser welding process, it is possible to apply sufficient heat deep inside the lead material, without relying on thermal conductivity (e.g., of other conventional methods). As energy density of the laser welding process is higher than other conventional methods, shorter cycle times can be achieved. Further, energy can be transferred directly into a weld zone / area, without affecting the surrounding, temperature- sensitive components such as first cover 20 which may be made of plastic material. That is, the laser welding process described herein provides consistent welding of post 18 and bushing 22 while keeping the bushing 22 (and post 18) sealed to first cover 20, e.g., without heating the post 18 and / or bushing 22 to the point where the battery case melts. In some embodiments, post 18 and / or bushing 22 may be made of lead material. In some embodiments, at least a portion of the cover 20 is coupled to the weld that results from the laser welding process, and at least the portion of the cover meets or exceeds a quality requirement. A quality requirement may include that the shape and / or form of the cover 20 is not changed during and / or after the welding, that a material parameter of the material of the cover is not changed beyond a predetermined threshold, etc.

[0041] Although the laser welding process of FIG. 7 is shown as welding a post to a bushing, the embodiments of the present disclosure are not limited as such, and the laser welding process may also be used to weld any other components, such as welding any of the welds 46, 48 (shown in FIG. 8) to any of the components of the lead assembly 24, etc.

[0042] FIG. 8 shows example battery after the laser welding process is completed. More specifically, the posts 18 and bushing 22 may be welded using the laser welding process shown in FIG. 7 to form welds 46, 48. More specifically, post 18a and bushing 22a shown in FIG. 5 are welded to form weld 46. Similarly, post 18b and bushing 22b shown in FIG. 6 are welded to form weld 48. In some embodiments, weld 46 is associated with a battery cell 14, and weld 48 is associated with a terminal of the battery 10. Once welds 46, 48 are completed, the posts 18 and bushings 22 are welded to each other. In addition, after welding has been completed, at least a portion of post 18 is integrated with bushing 22. In some embodiments, once welds 46, 48 are completed, the welds 46, 48 are sealed to first cover 20, e.g., such that an internal space (e.g., including battery cells 14) defined by the first cover 20 and case 12 is sealed. In some other embodiments, welding post 18 and bushing 22 forms a weld 46, 48 of single unitary construction that is sealed to first cover 20. Any one of welds 46, 48 may be a first weld or a weld button.

[0043] FIGS. 9 shows a view of an example weld 46 shown in FIG. 8. The weld 46 extends from first cover 20. That is, a portion of weld 46 extends from first cover 20 and is accessible and / or exposed such as to receive other components to which the weld 46 may be also coupled (welded). FIG. 10 shows a cross-section view of the example weld 46 of FIG. 9. Weld 46 is in physical contact with and / or coupled to the first cover 20. Further, weld 46 comprises at least a portion (e.g., previously melted portion) of post 18a and / or bushing 22a. For example, when the laser welding process described herein is used to create weld 46, weld 46 includes at least some material from post 18a and / or some material from bushing 22a. A gap 19 may be arranged between post 18a and bushing 22a.

[0044] In addition, weld 46 is not limited to having the shape or size shown and may be of any other shape or size. For example, weld 46 may also include additional material of post 18a and bushing 22a, which may fill at least a portion of the gap 19 between post 18a and bushing 22a. That is, gap 19 may be arranged to create a flow space such that melted material from weld 46 flows into and / or fill at least a portion of gap 19. Further, post 18a may be electrically coupled to one or more battery cells 14, such that an electrical connection may be established between weld 46 and battery cels 14.

[0045] FIG. 11 shows a view of an example weld 48 shown in FIG. 8. The weld 48 extends from first cover 20 and is coupled to and / or welded to terminal structure 33, which may be coupled to the first cover 20. That is, a portion of weld 48 extends from the first cover 20 and is accessible and / or exposed to other components (e.g., terminal structure 33) to which the weld 48 may be also coupled (welded). FIG. 12 shows a cross-section view of the example weld 48 of FIG. 11. Weld 48 may be in physical contact with and / or coupled to the first cover 20. Further, weld 48 comprises at least a portion (e.g., previously melted portion) of post 18b and / or bushing 22b. For example, when the laser welding process described herein is used to create weld 48, weld 48 includes at least some material from post 18b and / or some material from bushing 22b. A gap 21 may be arranged between post 18b and bushing 22b.

[0046] Of note, weld 48 is not limited to having the shape or size shown and may be of any other shape or size. For example, weld 48 may also include additional material of post 18b and bushing 22b, such as in the areas where post 18b and bushing 22b come in contact with each other, and the weld material may fill at least a portion of gap 21. That is, gap 21 may be arranged to create a flow space such that melted material from weld 48 flows into and / or fill at least a portion of gap 21. Further, post 18b may be electrically coupled to one or more battery cells 14, such that an electrical connection may be established between weld 48 and battery cels 14.

[0047] FIG. 13 shows a cross section view of an example weld 46 or weld 48 (e.g., after the process described with respect to FIG. 7 has been completed). Weld 46, 48 may include weld material such as material that have melted as part of the welding process and / or solidified after a predetermined time has lapsed and / or the weld 46, 48 has cooled below a predetermined temperature threshold. The material that has melted may include material from bushing 22 and / or post 18 (e.g., without melting or damaging the material from cover 20). Since laser welding provides a concentrated energy source, which allows controlling which area and / or depth of the post 18 and / or bushing 22 receives energy, several depths and diameters of the weld may be achieved. In this nonlimiting example, when weld 46, 48 is formed, several portions of the weld 46,48 may have different diameters, e.g., a first diameter dl, a second diameter d2, a third diameter d3, a fourth diameter d4, a fifth diameter d5, a sixth diameter or distance d6, a seventh diameter or distance d7, etc. at different depths of the weld 46, 48. Different depths of the weld 46, 48 are shown and may be measured with respect to different points of the weld 46, 48 and / or bushing 22 and / or cover 20. For example, the weld 46, 48 may have a depth ‘a’ measured from bushing portion 50 to weld portion 52, and depth ‘b’ may be measured bushing portion 54 to weld portion 56. However, the depths are not limited as such and may be measured from / to any other portions, e.g., from bushing portion 58 or bushing portion 60, and be more or less than two depths.

[0048] In this nonlimiting example, completed weld 46, 48 has three portions 62, 64, 66, where portion 62 may be a top portion (or crown portion) having a height hl extending from cover 20 (e.g., above post 18 and bushing 22). Portion 64 is contiguous to portion 62, may be within a portion of bushing 22, may include material from post 18 and / or bushing 22, and may be above a portion of post 18. The height of portion 64 may be h2. Further, post 18 may be cylindrical, have the shape of a truncated cone, of another structure having a radial shape, or have any other shape. Portion 66 may be a bottom portion (or root portions) having a height h3 and may surround at least a portion of post 18. Portion 66 may have a top diameter (e.g., given by d5 + d6), and be separated from bushing 22 a distance or diameter d7 at portions 52, 56, respectively. At least some material of portion 88 may flow into and fill at least a portion of gap 19, 21. Another portion of gap 19, 21 may be unfilled and may have a height h4. Thus, laser welding post 18 and bushing 22 may result in a weld 46, 48 that extends to predetermined depths (depths ‘a’, ‘b’, or other depths) and / or leaves a portion of height h4 which may not include weld material or where the weld material does not reach post 18 and / or bushing 22. In other words, laser welding post 18 and bushing 22 may result in a controlled process where the depth of the weld may meet one or more predetermined thresholds, without burning or damaging the cover 20.

[0049] FIG. 14 shows section A of the weld 46, 48 of FIG. 13 and another example depth ‘c’ measured from bushing portion 50 to bushing portion 70 where the diameter of the bottom portion 66 (e.g., root portion) of weld 46, 48 is d6. That is, the laser welding process may be arranged such that at a predetermined depth ‘c’ from a predetermined portion of bushing 22, i.e., portion 50, the diameter of portion 66 is less than and / or equal to, or greater than and / or equal to a predetermined diameter d6.

[0050] Similarly, FIG. 15 shows section B of the weld 46, 48 of FIG. 13 and another example depth ‘d’ measured from bushing portion 54 to bushing portion 72 where the diameter of the bottom portion 66 (e.g., root portion) of weld 46, 48 is d7. That is, the laser welding process may be arranged such that at a predetermined depth ‘d’ from a predetermined portion of bushing 22, i.e., portion 54, the diameter of portion 64 is less than and / or equal to, or greater than and / or equal to a predetermined diameter d7.

[0051] Further, the configuration of weld 46, 48 provides a coupling mechanism such that the post 18 and bushing 22 are secured to each other and to cover 20 without damaging the cover 20, while providing an electrical path to the battery cells and the battery management system for measuring cell parameters. Further, laser welding that results in weld 46, 48 allows for achieving a predetermined DOB that provides reliable, leak-tight sealing of the weld 46, 48.

[0052] In some embodiments, battery 10 comprises a lead assembly 24 coupled to a plurality of welds including weld 46 and weld 48. The lead assembly is electrically coupled to BMS 26 such that an electrical connection is established between BMS 26 and cells 14 via lead assembly 24 and the corresponding weld 46, 48. In some other embodiments, the weld 46, 48 is formed using a predetermined weld pattern and a predetermined weld time. The predetermined weld pattern and / or the predetermined weld time are based on whether the post 18 is coupled to a battery cell 14 or a battery terminal structure 23 or terminal post 25 (i.e., battery terminal).

[0053] FIG. 16 shows a flowchart of an example method of making a battery cell connection (e.g., welds 46, 48). The method includes inserting (Block S100) post 18 through the bushing 22, where at least a portion of the bushing 22 is in physical contact with the cover 20, directing (Block S102) a laser beam 42 to one or more areas of a plurality of areas and one or more depths of a plurality of depths of one or both of the post 18 and the bushing 22, and forming (Block S104) a weld 46, 48 comprising the bushing 22 and the post 18 coupled to the bushing 22 using the directed laser beam. At least the bushing 22 of the weld 46, 48 is sealed to the cover 20.

[0054] FIG. 17 shows a flowchart of another example method of making a battery cell connection (e.g., welds 46, 48) for establishing an electrical connection to battery cells 14 of a battery 10 is described. The battery 10 has a post 18, a bushing 22, a case 12 and a cover 20 sealed to the case 12. The post 18 is inserted through the bushing 22, and at least a portion of the bushing 22 is in physical contact with the cover 20 and the post 18. The bushing 22 includes a bushing material and has a bushing first portion 50 and a bushing second portion 54. The post 18 includes a post material. The method includes directing (Block S200) a laser beam 42 to one or more areas of a plurality of areas and one or more depths of a plurality of depths of one or both of the post 18 and the bushing 22 and forming (Block S202) a weld 46, 48 using the laser beam 42. The formed weld 46, 48 includes a weld first portion 62, a weld second portion 64, and a weld third portion 66. The weld first portion 62 extends away at least from the bushing 22. The weld second portion 64 is contiguous to the weld first portion 62, within the bushing 22, and over the post 18. The weld third portion 66 is contiguous to the weld second portion 64, within the bushing 22, and surrounding the post 18. The weld 46, 48 has one or both of a first depth ‘a’ measured from the bushing first portion 50 and a second depth ‘b’ measured from the bushing second portion 54. One or both of the first depth ‘a’ and the second depth ‘b’ meeting or exceeding a depth minimum threshold.

[0055] In some embodiments, the bushing 22 further comprises a bushing third portion 52 and a bushing fourth portion 56, and the method further includes directing the laser beam 42 to melt one or both of the bushing material and the post material to achieve the first depth ‘a’ measured from the bushing first portion 50 to the bushing third portion 52, and the second depth ‘b’ measured from the bushing second portion 54 to the bushing fourth portion 56.

[0056] In some other embodiments, the bushing 22 further comprises a bushing fifth portion 70 and a bushing sixth portion 72. The method further includes directing the laser beam 42 to melt one or both of the bushing material and the post material. The directed laser beam causes the weld 46, 48 to have a third depth ‘c’ measured from the bushing first portion 50 to the bushing fifth portion 70, and causes the weld 46, 48 to have a fourth depth ‘d’ measured from the bushing second portion 54 to the bushing sixth portion 72. The first depth ‘a’ is greater than the third depth ‘c’, and the second depth ‘b’ is greater than the fourth depth ‘d’.

[0057] In some embodiments, directing the laser beam 42 causes the weld third portion 66 to have a width that extends from the bushing fifth portion 70 to the post 18 and meets or exceeds a width threshold.

[0058] In some other embodiments, one or more of: (A) the post 18 and the weld 46, 48 define a gap 19, 21; (B) directing the laser beam 42 causes a portion of one or both of the bushing material and the post material to fill at least a portion of the gap 19, 21; (C) the weld 46, 48 is formed using a predetermined weld pattern and a predetermined weld time; and (D) one or both of the predetermined weld pattern and the predetermined weld time is based on whether the post 18 is coupled to a battery cell 14 or a battery terminal 23, 25.

[0059] Although the battery 10 is described as having a post 18, a bushing 22, a case 12 and a cover 20, the embodiments are not limited as such and the battery 10 may include one or more of each of the post 18, bushing 22, case 12, cover 20, and any other components as described herein. In a nonlimiting example, battery 10 has multiple posts 18 and multiple corresponding bushings 22 and / or welds 46, 48. One or more embodiments described herein are beneficial at least because the BMS 26 may be electrically coupled to battery cells 14 via welds 46, 48, posts 18, bushings 22, e.g., for determining battery cell parameters such as voltage, state of charge, state of health, etc., while controlling the DOB of welds 46, 48, and protecting other battery components such as cover 20 (e.g., from melting from excessive heat of conventional welding techniques).

[0060] It will be appreciated by persons skilled in the art that the embodiments described herein are not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. A variety of modifications and variations are possible in light of the above teachings without departing from the scope of the following claims.

Claims

What is claimed is:

1. An apparatus arranged for establishing an electrical connection to battery cells (14) of a battery (10), the apparatus comprising: a bushing (22) comprising a bushing material and having a bushing first portion (50) and a bushing second portion (54); a post (18) in physical contact with the bushing (22) and comprising a post material; a weld (46, 48) welded using laser welding and comprising the bushing material and the post material, the weld (46, 48) comprising: a weld first portion (62) extending away at least from the bushing (22); a weld second portion (64) contiguous to the weld first portion (62), within the bushing (22) and over the post (18); and a weld third portion (66) contiguous to the weld second portion (64), within the bushing (22) and surrounding the post (18), the weld (46, 48) having one or both of a measured from the bushing first portion (50) and a second depth (b) measured from the bushing second portion (54), one or both of the first depth (a) and the second depth (b) meeting or exceeding a depth minimum threshold.

2. The apparatus of Claim 1, wherein the bushing (22) further comprises a bushing third portion (52) and a bushing fourth portion (56), the first depth (a) is measured from the bushing first portion (50) to the bushing third portion (52), and the second depth (b) is measured from the bushing second portion (54) to the bushing fourth portion (56).

3. The apparatus of any one of Claims 1 and 2, wherein the bushing (22) further comprises a bushing fifth portion (70) and a bushing sixth portion, the weld (46, 48) has a third depth (c) measured from the bushing first portion (50) to the bushing fifth portion (70), and the weld (46, 48) has a fourth depth (d) measured from the bushing second portion (54) to the bushing sixth portion (72), the first depth (a) being greater than the third depth (c), the second depth (b) being greater than the fourth depth (d).

4. The apparatus of Claim 3, wherein the weld third portion (66) has a width that extends from the bushing fifth portion (70) to the post (18) and meets or exceeds a width threshold.

5. The apparatus of any one of Claims 1-4, wherein the post (18) and the weld (46, 48) define a gap (19, 21) arranged to receive at least a portion of one or both of the bushing material and the post material.

6. A battery (10) comprising: a cover (20) and a case (12) coupled to the cover (20); a bushing (22) coupled to the cover (20), comprising a bushing material, and having a bushing first portion (50) and a bushing second portion (54); a post (18) in physical contact with the bushing (22) and comprising a post material; and a weld (46, 48) welded using laser welding, the weld (46, 48) being coupled to the cover and comprising the bushing material and the post material, the weld (46, 48) comprising: a weld first portion (62) extending away from the cover; a weld second portion (64) contiguous to the weld first portion (62), within the bushing (22) and over the post (18); and a weld third portion (66) contiguous to the weld second portion (64), within the bushing (22) and surrounding the post (18), the weld (46, 48) having one or both of a first depth (a) measured from the bushing first portion (50) and a second depth (b) measured from the bushing second portion (54), one or both of the first depth (a) and the second depth (b) meeting or exceeding a depth minimum threshold.

7. The battery (10) of Claim 6, wherein the bushing (22) further comprises a bushing third portion (52) and a bushing fourth portion (56), the first depth (a) is measured from the bushing first portion (50) to the bushing third portion (52), and the second depth (b) is measured from the bushing second portion (54) to the bushing fourth portion (56).

8. The battery (10) of any one of Claims 6 and 7, wherein the bushing (22) further comprises a bushing fifth portion (70) and a bushing sixth portion (72), the weld (46, 48) has a third depth (c) measured from the bushing first portion (50) to the bushing fifth portion (70), and the weld (46, 48) has a fourth depth (d) measured from the bushing second portion (54) to the bushing sixth portion (72), the first depth (a) being greater than the third depth (c), the second depth (b) being greater than the fourth depth (d).

9. The battery (10) of Claim 8, wherein the weld third portion (66) has a width that extends from the bushing fifth portion (70) to the post (18) and meets or exceeds a width threshold.

10. The battery (10) of any one of Claims 6-9, wherein the post (18) and the weld (46, 48) define a gap (19, 21) arranged to receive at least a portion of one or both of the bushing material and the post material.

11. The battery (10) of any one of Claims 6-10, wherein at least a portion of the cover coupled to the weld (46, 48) meets or exceeds a quality requirement.

12. The battery (10) of any one of Claims 6-11, wherein the battery (10) further includes a lead assembly (24) coupled to the weld (46, 48).

13. The battery (10) of Claim 12, wherein the battery (10) further includes a battery management system, BMS, (26) electrically coupled to the lead assembly (24).

14. The battery (10) of Claim 13, wherein the battery (10) further includes at least one cell (14) and the BMS (26) is electrically coupled to the at least one cell (14) via the lead assembly (24) and the weld (46, 48).

15. The battery (10) of Claims 14, wherein the weld (46, 48) is at least one weld (46, 48) of a plurality of welds (46, 48), the at least one weld (46, 48) corresponding to a battery terminal structure (23) or at least one cell (14).

16. A method of making a weld (46, 48) for establishing an electrical connection to battery cells (14) of a battery (10), the battery (10) having a post (18), a bushing (22), a case and a cover sealed to the case, the post (18) being inserted through the bushing (22), at least a portion of the bushing (22) being in physical contact with the cover (20) and the post (18), the bushing (22) comprising a bushing material and having a bushing first portion (50) and a bushing second portion (54), the post (18) comprising a post material, the method comprising:directing (S200) a laser beam (42) to one or more areas of a plurality of areas and one or more depths of a plurality of depths of one or both of the post (18) and the bushing (22); and forming (S202) a weld (46, 48) using the laser beam, the formed weld (46, 48) comprising: a weld first portion (62) extending away at least from the bushing (22); a weld second portion (64) contiguous to the weld first portion (62), within the bushing (22) and over the post (18); and a weld third portion (66) contiguous to the weld second portion (64), within the bushing (22) and surrounding the post (18), the weld (46, 48) having one or both of a first depth (a) measured from the bushing first portion (50) and a second depth (b) measured from the bushing second portion (54), one or both of the first depth (a) and the second depth (b) meeting or exceeding a depth minimum threshold.

17. The method of Claim 16, wherein the bushing (22) further comprises a bushing third portion (52) and a bushing fourth portion (56), and the method further includes: directing the laser beam (42) to melt one or both of the bushing material and the post material to achieve the first depth (a) measured from the bushing first portion (50) to the bushing third portion (52), and the second depth (b) measured from the bushing second portion (54) to the bushing fourth portion (56).

18. The method of any one of Claims 16 and 17, wherein the bushing (22) further comprises a bushing fifth portion (70) and a bushing sixth portion (72), and the method further includes: directing the laser beam (42) to melt one or both of the bushing material and the post material, the directed laser beam causing the weld (46, 48) to have a third depth (c) measured from the bushing first portion (50) to the bushing fifth portion (70), and causing the weld (46, 48) to have a fourth depth (d) measured from the bushing second portion (54) to the bushing sixth portion (72), the first depth (a) being greater than the third depth (c), the second depth (b) being greater than the fourth depth (d).

19. The method of Claim 18, wherein directing the laser beam (42) causes the weld third portion (66) to have a width that extends from the bushing fifth portion (70) to the post (18) and meets or exceeds a width threshold.

20. The method of any one of Claims 16-19, wherein one or more of: the post (18) and the weld (46, 48) define a gap (19, 21); directing the laser beam (42) causes a portion of one or both of the bushing material and the post material to fill at least a portion of the gap (19, 21); the weld (46, 48) is formed using a predetermined weld pattern and a predetermined weld time; and one or both of the predetermined weld pattern and the predetermined weld time is based on whether the post (18) is coupled to a battery cell (14) or a battery terminal (23,

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