Battery Pack

Abstract

A battery pack includes a battery pack housing, a plurality of battery pack terminals, and a plurality of battery cells supported within the battery pack housing. At least one battery cell includes a battery cell terminal. The battery pack also includes a composite fuse electrically connected between the battery cell terminal of at least one battery cell and at least one battery pack terminal. The composite fuse includes a first material and a second material having a lower melting point than the first material. The composite fuse includes a first portion, a second portion, and a fuse portion, the first portion being electrically connected to the battery cell terminal, the second portion being electrically connected to at least one battery pack terminal, and the fuse portion connecting the first portion to the second portion. The fuse portion is configured to form an interruption between the first portion and the second portion during a hard short circuit event.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to co-pending U.S. Provisional Patent Application No. 63 / 223,730, filed on July 20, 2021, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to a battery pack and, more particularly, to a battery pack for use with an apparatus or device such as a power tool. Background Art

[0004] In a battery pack, such as a power tool battery pack, protection may be provided by using a fuse in the current path of the battery pack. Utility Model Content

[0005] In one aspect, the present disclosure provides a battery pack comprising a battery pack housing, a plurality of battery pack terminals, and a plurality of battery cells supported within the battery pack housing and electrically connected to each other. At least one battery cell comprises a battery cell terminal. The battery pack also comprises a composite fuse electrically connected between the battery cell terminal of at least one battery cell and at least one battery pack terminal. The composite fuse comprises a first material and a second material having a lower melting point than the first material. The composite fuse comprises a first portion, a second portion, and a fuse portion, the first portion being electrically connected to the battery cell terminal, the second portion being electrically connected to at least one battery pack terminal, and the fuse portion connecting the first portion to the second portion. The fuse portion is configured to form an interruption between the first portion and the second portion during a hard short circuit event.

[0006] In some configurations, the second material is coated in the first material on each of the first side and the second side. In some configurations, the second material is embedded in the first material. In some configurations, the fuse portion is attached to the first portion and to the second portion by ultrasonic welding.

[0007] In another aspect, the present disclosure provides a battery pack comprising a battery pack housing, a battery pack negative terminal and a battery pack positive terminal, and a plurality of battery cells supported within the battery pack housing and electrically connected to each other, to the battery pack negative terminal, and to the battery pack positive terminal. At least one battery cell comprises a battery cell terminal. The battery pack also comprises a composite fuse electrically connected between the battery cell terminal and the battery pack negative terminal. The composite fuse comprises a first material and a second material having a lower melting point than the first material. The composite fuse comprises a first portion, a second portion, and a fuse portion, the first portion being electrically connected to the battery cell terminal, the second portion being electrically connected to at least one of the battery pack negative terminal and the battery pack positive terminal, and the fuse portion connecting the first portion to the second portion. The fuse portion is configured to form an interruption between the first portion and the second portion during a hard short circuit event. The fuse portion is formed of a second material.

[0008] In another aspect, the present disclosure provides a composite fuse for a battery pack. The composite fuse is configured to be connected between a battery cell terminal of the battery pack and a battery pack terminal of the battery pack. The composite fuse includes a first portion, a second portion, and a fuse portion, the first portion being located at a first end of the composite fuse, the second portion being located at a second end of the composite fuse, and the fuse portion connecting the first portion to the second portion. The fuse portion is configured to form an interruption between the first portion and the second portion during a hard short circuit event. Each of the first portion, the second portion, and the fuse portion is at least partially formed of a first material. The first portion and the second portion are also partially formed of a second material having a lower melting point than the first material.

[0009] Other aspects of the disclosure will become apparent by consideration of the detailed description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a three-dimensional diagram of a battery pack.

[0011] Figure 2 yes Figure 1 A three-dimensional view of a battery pack with some parts removed.

[0012] Figure 3 yes Figure 1 Detailed perspective view of a battery pack with some parts removed and the fuses of the battery pack shown.

[0013] Figure 4 and Figure 5A Shows Figure 1 A fuse of a battery pack according to another embodiment.

[0014] Figure 5B Shows Figure 1 A fuse of a battery pack according to another embodiment.

[0015] Figure 6 and Fig. 7A Shows Figure 1 A fuse of a battery pack according to another embodiment.

[0016] Figure 7B Shows Figure 1 A fuse of a battery pack according to another embodiment.

[0017] Fig. 8A and Figure 8B It shows that it can form Figure 1 The fuse material strip of the battery pack.

[0018] Fig.9A and Fig. 9B It is shown that according to another embodiment, Figure 1 The fuse material strip of the battery pack.

[0019] Fig. 10A and Fig. 10B It is shown that according to another embodiment, Figure 1 The fuse material strip of the battery pack.

[0020] Before describing in detail any embodiment of the present disclosure, it should be understood that the present disclosure is not limited in its application to the embodiment details and component arrangements set forth in the following description or shown in the following figures. The present disclosure can have other embodiments and can be practiced or performed in various ways. In addition, it should be understood that the words and terms used herein are for descriptive purposes and should not be considered as limiting. DETAILED DESCRIPTION

[0021] Figures 1 to 3 A battery pack 105 is shown, which can be used to provide power to electrical equipment or devices. Such electrical devices may include, for example, power tools (e.g., drills, saws, pipe cutters, impact wrenches, etc.), outdoor tools (e.g., snow blowers, vegetation cutters, etc.), lighting equipment, power supplies, and the like.

[0022] As in Figure 1 As shown in FIG. 1 , the battery pack 105 includes a battery pack housing 110 and a battery pack terminal 115 protruding through an opening formed in the housing. The battery pack terminal 115 is mechanically and electrically coupled to a corresponding terminal (not shown) provided on an electrical device to transfer power from the battery pack 105 to the device. In some embodiments, the battery pack terminal 115 may include a power line, a ground line, and one or more communication lines.

[0023] Figure 2 The battery pack 105 is shown with the housing 110 removed to expose the internal components of the battery pack 105. Figure 2 As shown in FIG. 1 , the battery pack 105 includes a printed circuit board (PCB) 120 that supports the battery pack terminals 115 and control circuitry 116 for controlling operation of the battery pack 105 .

[0024] The battery pack 105 shown includes a plurality of cylindrical battery cells 125 that are electrically connected together to provide the desired output (e.g., rated voltage, current capacity, etc.) of the battery pack 105. In the shown configuration, the battery pack 105 includes a group of five battery cells 125 connected in series (a "5S1P" battery pack). In other configurations (not shown), the battery pack 105 can include two groups of five battery cells connected in series (a "5S2P" pack), or three groups of five battery cells connected in series (a "5S3P" pack). In other configurations, the battery pack 105 may alternatively include less than five or more than five battery cells 125, and the battery cells 125 may be electrically connected in other configurations. The rated output voltage of the battery pack 105 shown is at least 18V. The battery pack 105 is rechargeable, and the battery cells 125 may have a lithium-based chemistry (e.g., lithium, lithium-ion, etc.) or any other suitable chemistry.

[0025] The battery pack 105 includes a top shell 130 and a bottom shell 135 that secure the battery cells 125 in a single row within the battery pack 105. The wedge elements 140 protrude from the respective shells 130, 135 to contact the battery cells 125 (e.g., to hold the battery cells 125 in place). The shells 130, 135 generally surround the circumferential side surfaces of the battery cells 125, while leaving the first end faces 150a and the second end faces 150b of the battery cells 125 generally exposed to allow the battery cells 125 to be electrically connected in a circuit. Specifically, the first end face 150a defines a first terminal 155a (e.g., a positive terminal) of the battery cell 125, and the second end face 150b defines a second terminal 155b (e.g., a negative terminal) of the battery cell 125.

[0026] Reference Figure 3, a fuse 160 can be set in the current path of the battery pack 105 to provide protection in the event of, for example, a hard short circuit event or an overload event (i.e., when the current flowing through the battery pack circuit exceeds a predetermined limit). In the illustrated construction, the fuse 160 is connected between the second terminal 155b of one of the battery cells 125 and the battery pack negative terminal 165a in the battery pack terminal 115. In other constructions, the fuse 160 can be set between the first terminal 155a of the battery cell 125 and the battery pack positive terminal 165b in the battery pack terminal 115 (not shown). As shown, the fuse 160 includes a first end 170 and a second end 175, the first end being directly attached to the second terminal 155b, and the second end being connected to the battery pack negative terminal 165a. In other embodiments (not shown), the first end 170 can alternatively be connected to a bus 180 that electrically connects two or more terminals of the battery cell.

[0027] The fuse 160 includes a fusible portion 185 disposed between the first end 170 and the second end 175. During a hard short of the fuse 160, the fusible portion 185 is configured to form a discontinuity (e.g., due to melting) between the first end 170 and the second end 175, thereby disconnecting the first end 170 from the second end 175 and interrupting the current path of the battery pack 105.

[0028] Figures 4 to 5B A composite fuse 190 formed of two different conductive materials M1, M2 (e.g., two different metals, metal alloys, and the like) is shown. Composite fuse 190 can be used in battery pack 105 to replace fuse 160 described above. In the illustrated embodiment, composite fuse 190 includes some parts made of a first material M1 (e.g., a copper-based material) and other parts made of a second material M2 (e.g., an aluminum-based material). Specifically, composite fuse 190 includes a first portion 195 defining a first end 200, a second portion 205 defining a second end 210, and a fusible portion 215 extending between and connecting the first portion 195 and the second portion 205. The first portion 195 and the second portion 205 are at least partially formed of the first material M1, and the fusible portion 215 is at least partially formed of the second material M2. In some embodiments, the fusible portion 215 is formed as a whole by the second material M2. The second material M2 has a lower melting point than the first material M1. This allows the fusible portion 215 to release relatively less heat during a hard short circuit event compared to conventional fuses where the fusible portion is formed of the same material M1 as the first portion 195 and the second portion 205. In addition, this can prevent the housing 110 ( Figure 1) of the composite fuse 190 adjacent to the second material M2 melts during a hard short circuit event. In addition, mica can be disposed adjacent to the fuse in the battery pack as a thermal insulator to prevent the housing from melting during a hard short circuit event. However, by implementing the composite fuse 190 having the fusible portion 215 formed of the second material M2, a certain amount of mica disposed in the battery pack 105 can be reduced or omitted.

[0029] Continue to refer to Figure 4 The composite fuse 190 can be formed as a generally flat member and then bent into, for example, an L-shape (such as in Figure 5A and 5B ) to be implemented in the battery pack 105. In the illustrated embodiment, the fusible portion 215 is defined by a first slot 220 that extends across the width of the composite fuse 190 (i.e., as shown in Figure 4 The width W1 of the fusible portion 215 is formed by a portion of the first groove 220 (in a direction transverse to the longitudinal extent of the composite fuse 190). The first groove 220 partially separates the first portion 195 from the second portion 205. The fusible portion 215 can be further defined by a second groove 225 that is transverse to the first groove 220 (i.e., as shown in FIG. Figure 4 , extending in a direction parallel to the longitudinal extent of the composite fuse 190) to form a longitudinal length L1 of the fusible portion 215. The fusible portion 215 defines a minimum cross-sectional area in the composite fuse 190 along a current flow path through the composite fuse 190 to ensure that the composite fuse 190 melts in the fusible portion 215 to form a discontinuity between the first portion 195 and the second portion 205 during a hard short circuit event.

[0030] exist Figure 5A In the embodiment shown in FIG. 1 , the entire composite fuse 190 (including the first and second parts 195, 205 and the fusible part 215) can be formed of the second material M2 as the core material, and then the first material M1 can be coupled to the second material M2 in each of the first and second parts 195, 205. The first material M1 can be coupled to the second material M2, for example, by electroplating or plasma coating.

[0031] exist Figure 5B In the embodiment shown in , the first portion 195 and the second portion 205 can be formed from the first material M1 and then the central section defining the fusible portion 215 can be attached to the first portion 195 and to the second portion 205 by ultrasonic welding.

[0032] Figures 6 to 7B FIG. 2 shows a composite fuse 290 according to another embodiment of the present disclosure. The composite fuse 290 is combined with the above Figures 4 to 5BThe composite fuse 190 described is similar. Features of composite fuse 290 that are similar to the above-described features of composite fuse 190 are designated with the same reference numerals "plus 100."

[0033] Composite fuse 290 is also formed of two different conductive materials M1, M2, and can be used in battery pack 105 instead of fuse 160 described above. In the illustrated embodiment, composite fuse 290 includes a first portion 295 defining a first end 300, a second portion 305 defining a second end 310, and a fusible portion 315 extending between and connecting first portion 295 and second portion 305. Composite fuse 290 is also formed as a generally flat member ( Figure 6 ), and then bends to include a bend or ridge in the region of the fusible portion 315 ( Fig. 7A , Figure 7B In the illustrated embodiment, the fusible portion 315 is defined by a pair of lateral slots 320 that extend inward from each lateral side of the composite fuse 290 (ie, as in FIG. Figure 6 2, extending in a direction transverse to the longitudinal extent of the composite fuse 290) to form a width W2 of the fusible portion 315 and a length L2 of the fusible portion 315. The fusible portion 315 defines a minimum cross-sectional area in the composite fuse 290 along the current flow path through the composite fuse 290 to ensure that the composite fuse 290 melts in the fusible portion 315 to form a discontinuity between the first portion 295 and the second portion 305 during a hard short circuit event. The cross-sectional area of ​​the fusible portion 315 is larger than the cross-sectional area of ​​the fusible portion 215 of the composite fuse 190 described above, so that the composite fuse 290 has a higher rated current load than the composite fuse 190.

[0034] exist Fig. 7A In the embodiment shown in FIG. 2 , the entire composite fuse 290 (including the first and second parts 295 and 305 and the fusible part 315) can be formed of the second material M2 as the core material, and then the first material M1 can be coupled to the second material M2 in each of the first and second parts 295 and 305. The first material M1 can be coupled to the second material M2 by, for example, electroplating or plasma coating.

[0035] exist Figure 7B In the embodiment shown in , the first portion 295 and the second portion 305 can be formed from the first material M1 and then the central section defining the fusible portion 315 can be attached to the first portion 295 and to the second portion 305 by ultrasonic welding.

[0036] Fig. 8A and Figure 8BA material strip 405 capable of forming a composite fuse 190, 290 is shown. The material strip 405 is a clad metal material strip 405 provided as a covering layer on both sides, the covering layer comprising a second material M2 (e.g., an aluminum-based material) coated in a first material M1 (e.g., a copper-based material). The material strip 405 comprises an inner layer 410 formed of the second material M2, and a first outer layer 415 and a second outer layer 420 each formed of the first material M1. In some configurations, the first outer layer 415, the inner layer 410, and the second outer layer 420 can be provided in a ratio of 10 / 80 / 10. In other configurations, the content of the second material M2 in the material of the material strip 405 can be greater than 80%.

[0037] Fig.9A and Fig. 9B Another embodiment 505 of a material strip capable of forming a composite fuse 190, 290 is shown. The material strip 505 is a clad metal material strip 505 disposed as an edge layer along each respective edge, the edge layer comprising a second material M2 (e.g., an aluminum-based material) bonded to a first material M1 (e.g., a copper-based material). The first material M1 and the second material M2 define interlocking fingers 510a, 510b that engage one another to improve the integrity of the bond.

[0038] Fig. 10A and Fig. 10B Another embodiment 605 of a material strip capable of forming a composite fuse 190, 290 is shown. The material strip 605 is a clad metal material strip 605 provided as an inner layer comprising a second material M2 (e.g., an aluminum-based material) embedded in a groove formed in a first material M1 (e.g., a copper-based material).

[0039] Although the disclosure has been described in detail with reference to several preferred embodiments, various variations and modifications exist within the scope and spirit of one or more independent aspects of the disclosure as described.

Claims

1. A battery pack, characterized in that: include: Battery pack housing; Multiple battery pack terminals; a plurality of battery cells supported within the battery pack housing and electrically connected to each other, at least one of the battery cells including a battery cell terminal; as well as A composite fuse electrically connected between a battery cell terminal of the at least one battery cell and at least one battery pack terminal, the composite fuse comprising a first material and a second material having a lower melting point than the first material, the composite fuse comprising a first portion electrically coupled to the battery cell terminal, a second portion electrically coupled to the at least one battery terminal, and A fuse portion connects the first portion to the second portion, the fuse portion being configured to form a discontinuity between the first portion and the second portion during a hard short circuit event.

2. The battery pack according to claim 1, wherein: The second material is clad in the first material on each of a first side of the composite fuse and a second side of the composite fuse, the second side being located opposite the first side.

3. The battery pack according to claim 1, wherein: The second material is embedded in the first material.

4. The battery pack according to claim 1, wherein: The fuse portion is attached to the first portion and to the second portion by ultrasonic welding.

5. The battery pack according to claim 1, wherein: The first portion is at least partially formed from the first material, and the fuse portion is at least partially formed from the second material.

6. The battery pack according to claim 1, wherein: Each of the first portion, the second portion, and the fuse portion is at least partially formed from the second material.

7. The battery pack according to claim 6, wherein: The first portion and the second portion are formed in part from the first material.

8. The battery pack according to claim 1, wherein: The first material is coupled to the second material by at least one of electroplating and plasma coating.

9. The battery pack according to claim 1, wherein: The composite fuse also includes a first elongated slot and a second elongated slot, wherein the first elongated slot partially separates the first part from the second part, the second elongated slot is connected to the first elongated slot and extends perpendicularly to the first elongated slot, and the second elongated slot defines the longitudinal length of the fuse part.

10. The battery pack according to claim 1, wherein: A current flow path between the first portion and the second portion is defined along the fuse portion, and wherein a cross-sectional area defined by the fuse portion along the current flow path is minimal in the composite fuse.

11. A battery pack, characterized in that: include: Battery pack housing; a battery pack negative terminal and a battery pack positive terminal; a plurality of battery cells supported within the battery pack housing and electrically connected to each other, to the battery pack negative terminal, and to the battery pack positive terminal, at least one battery cell including a battery cell terminal; A composite fuse is electrically connected between the battery cell terminal and the negative terminal of the battery pack, the composite fuse comprises a first material and a second material having a lower melting point than the first material, the composite fuse comprises a first portion electrically coupled to the battery cell terminal, a second portion electrically coupled to at least one of the battery negative terminal and the battery positive terminal, and A fuse portion connects the first portion to the second portion, the fuse portion being configured to form a discontinuity between the first portion and the second portion during a hard short circuit event, the fuse portion being formed from the second material.

12. The battery pack according to claim 11, wherein: The first portion and the second portion are each formed of each of the first material and the second material.

13. The battery pack according to claim 11, wherein: The first portion and the second portion are formed of only the first material.

14. The battery pack according to claim 11, wherein: The fuse portion is attached to the first portion and to the second portion by ultrasonic welding.

15. The battery pack according to claim 11, wherein: The first material is coupled to the second material by at least one of electroplating and plasma coating.

16. The battery pack according to claim 11, wherein: The composite fuse also includes a first elongated slot and a second elongated slot, wherein the first elongated slot partially separates the first part from the second part, the second elongated slot is connected to the first elongated slot and extends perpendicularly to the first elongated slot, and the second elongated slot defines the longitudinal length of the fuse part.

17. The battery pack according to claim 11, wherein: A current flow path between the first portion and the second portion is defined along the fuse portion, and wherein a cross-sectional area defined by the fuse portion along the current flow path is minimal in the composite fuse.

18. The battery pack according to claim 11, wherein: The second material is encased in the first material on each of a first side of the first portion and a second side of the first portion, the second side being located opposite the first side.

19. The battery pack according to claim 11, wherein: A first lateral groove is defined in the first lateral side of the composite fuse, and a second lateral groove is defined in the second lateral side of the composite fuse, the second lateral side is positioned opposite to the first lateral side, and wherein the fuse portion is located between the first lateral groove and the second lateral groove.

20. A composite fuse for a battery pack, characterized in that: The composite fuse is configured to be coupled between a battery cell terminal of the battery pack and a battery pack terminal of the battery pack, and the composite fuse comprises: a first portion, the first portion being located at a first end of the composite fuse; a second portion located at a second end of the composite fuse; and a fuse portion connecting the first portion to the second portion, the fuse portion being configured to form a discontinuity between the first portion and the second portion during a hard short circuit event; wherein each of the first portion, the second portion, and the fuse portion is at least partially formed of a first material; and The first part and the second part are also partially formed of a second material having a lower melting point than the first material.

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