Battery pack for power tool, and electric device

Abstract

A battery pack for a power tool, the battery pack comprising: a housing assembly, in which a closed cavity is formed; and a battery module, which is arranged within the closed cavity, wherein an outer housing surface of at least one side of the housing assembly is provided with a heat dissipation channel that directs forced convection across the outer housing surface of the battery pack so as to dissipate heat for the battery pack.

Description

Battery packs and electrical equipment for power tools

[0001] This application claims priority to Chinese patent applications filed on March 26, 2025, with application number 202510365534.2, and filed on December 25, 2025, with application number 202511982417.7, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of power tool technology, and for example to a battery pack and electrical equipment for power tools. Background Technology

[0003] After evolving from manual to fuel-powered systems, most tools widely used in landscaping, construction, and other applications now utilize lithium batteries for power. A key aspect of lithium battery technology is safety, encompassing both microscopic safety (related to the materials used in the cell's positive and negative electrodes) and macroscopic safety (related to heat dissipation, compression, and drops). Among these, design considerations related to thermal runaway have always been paramount.

[0004] This section provides background information related to this application, which is not necessarily prior art. Summary of the Invention

[0005] One object of this application is to solve or at least alleviate some or all of the aforementioned problems. To this end, this application provides a battery pack and electrical device for power tools.

[0006] A battery pack for power tools includes: a housing assembly having a sealed cavity; a battery module disposed within the sealed cavity; a heat dissipation guide portion formed on the outer surface of at least one side of the housing assembly; the power tool having a receiving compartment for accommodating the battery pack; the heat dissipation guide portion cooperating with the inner wall of the receiving compartment to form a heat dissipation channel to guide forced convection flow through the heat dissipation channel and dissipate heat from the battery pack.

[0007] In some embodiments, the housing assembly includes a heat dissipation housing with heat dissipation guides, wherein the heat dissipation guides are heat dissipation fins formed on the heat dissipation housing.

[0008] In some embodiments, the spacing between the heat dissipation fins is greater than or equal to 3 mm and less than or equal to 8 mm.

[0009] In some embodiments, the spacing between adjacent heat dissipation fins at different locations is at least partially different.

[0010] In some embodiments, the fin depth of the heat dissipation fins is greater than or equal to 10 mm and less than or equal to 20 mm.

[0011] In some embodiments, the battery module has two polar end faces perpendicular to the extending direction of the battery cells within the module, and the polar end faces are disposed opposite to the heat dissipation housing.

[0012] In some embodiments, the device further includes thermally conductive adhesive that covers at least a portion of the polar end face and is in thermal contact with the heat dissipation housing. The thermally conductive adhesive conducts the heat generated by the battery cell to the heat dissipation housing, and then conducts it out to the external environment through the heat dissipation housing.

[0013] In some embodiments, the heat dissipation housing includes a metal plate and / or a heat-dissipating plastic component.

[0014] In some embodiments, the heat dissipation channel guides forced convection to flow from top to bottom across the outer surface of the battery pack housing to dissipate heat from the battery pack.

[0015] A battery pack includes: a housing assembly; a battery module disposed within the housing assembly; a heat dissipation guide portion formed on at least one outer surface of the housing assembly; the battery pack further includes a cover plate disposed outside the heat dissipation housing with the heat dissipation guide portion, and cooperating with the heat dissipation guide portion to form a heat dissipation channel to guide forced convection flow through the heat dissipation channel and dissipate heat from the battery pack.

[0016] In some embodiments, the cover is detachably mounted to the outside of the heat sink housing.

[0017] A battery pack for power tools includes: a housing assembly having a sealed cavity; a battery module disposed within the sealed cavity; and a heat dissipation channel provided on at least one side of the outer surface of the housing assembly, the heat dissipation channel guiding forced convection flow through the outer surface of the battery pack housing to dissipate heat from the battery pack.

[0018] In some embodiments, the outer surface of the housing assembly on at least one side is provided with a longitudinal heat dissipation channel.

[0019] In some embodiments, the outer surface of the housing assembly on at least one side is provided with a lateral heat dissipation channel.

[0020] In some embodiments, the heat dissipation channel guides forced convection to flow from top to bottom across the outer surface of the battery pack to dissipate heat from the battery pack.

[0021] In some embodiments, the power tool or charger is provided with a cooling fan that generates forced convection.

[0022] In some embodiments, a protective net is also included, which is disposed at the bottom of the battery pack; when the battery pack is installed on a power tool, the protective net is generally positioned above the cooling fan.

[0023] In some embodiments, a heat dissipation guide is formed on the outer surface of at least one side of the housing assembly, and the power tool has a receiving compartment for accommodating a battery pack, the inner wall of which cooperates with the heat dissipation guide to form a heat dissipation channel.

[0024] In some embodiments, a heat dissipation guide portion is formed on the outer surface of at least one side of the housing assembly, and the battery pack further includes a cover plate disposed on the outside of the heat dissipation housing having the heat dissipation guide portion, the cover plate cooperating with the heat dissipation guide portion to form a heat dissipation channel.

[0025] A battery pack for power tools includes: a housing assembly having a sealed cavity; a battery module disposed within the sealed cavity; and a heat dissipation channel provided on at least one side of the outer surface of the housing assembly, the heat dissipation channel guiding forced convection to flow from top to bottom across the outer surface of the battery pack housing for heat dissipation of the battery pack.

[0026] In some embodiments, the outer surface of the housing assembly on at least one side is provided with a longitudinal heat dissipation channel.

[0027] A battery pack includes: a housing assembly having a sealed cavity; a battery module disposed within the sealed cavity; and a heat dissipation channel provided on at least one side of the outer surface of the housing assembly to guide forced convection flow through the heat dissipation channel and dissipate heat from the battery pack, wherein the housing containing the heat dissipation channel is made of a metal plate.

[0028] An electrical device includes: a battery mounting section having device terminals configured to be electrically connected to battery terminals of a battery pack for power transmission between the battery pack and the electrical device; the battery pack includes: a housing assembly having a sealed cavity for accommodating a battery module, and a heat dissipation channel provided on at least one outer surface of the housing assembly; the electrical device further includes: a cooling fan fixed to the electrical device and disposed near the battery pack, configured to generate forced convection flowing through the heat dissipation channel.

[0029] In some embodiments, the electrical equipment includes a charger or power tool, and a cooling fan is disposed at the bottom of the battery mounting section.

[0030] In some embodiments, power tools include one or more of the following: push-type working machine, riding-type working machine, self-propelled working machine, and wheeled working machine.

[0031] In some embodiments, the device further includes a vibration damper disposed between the cooling fan and the device body.

[0032] A battery pack for power tools includes: a housing assembly including at least one heat sink; at least one battery module disposed within the housing assembly, including a plurality of battery cells and having two polarized end faces perpendicular to the longitudinal extension direction of the battery cells; the heat sink has a thermal conductivity greater than 0.3 W / (m·K); the battery pack further includes: thermally conductive adhesive, which covers at least a portion of the polarized end faces and is in thermal contact with the heat sink; the thermally conductive adhesive is configured to conduct heat generated by the battery cells to the heat sink and conduct it out to the external environment through the heat sink.

[0033] In some embodiments, the heat sink is a metal plate.

[0034] In some embodiments, the device further includes a thermally conductive plastic component disposed between the metal plate and the thermally conductive adhesive.

[0035] In some embodiments, an oxide layer is formed on the surface of the heat sink or metal plate.

[0036] In some embodiments, it further includes: a support assembly disposed within the housing assembly and configured to support the battery module; the support assembly is at least partially made of a material with variable thermal conductivity.

[0037] In some embodiments, the bracket assembly is provided with a plurality of support slots to support a plurality of battery cells of the battery module, and the depths of the plurality of support slots are not completely consistent.

[0038] In some embodiments, the minimum spacing between individual battery cells is greater than or equal to 3 mm.

[0039] In some embodiments, at least the outer surface of the heat sink or metal plate is provided with a heat dissipation channel, and the power tool is provided with a cooling fan. The airflow generated by the cooling fan flows through the heat dissipation channel and carries away the heat.

[0040] In some embodiments, the outer surface of the heat sink or metal plate away from the battery module is provided with heat dissipation fins, and the heat dissipation fins cooperate with the inner wall of the battery compartment used by the power tool to accommodate the battery pack to form a heat dissipation channel.

[0041] In some embodiments, the device further includes: a cover plate disposed on the outside of the heat sink or metal plate; heat sink fins are formed on the outer surface of the heat sink or metal plate away from the battery module, and the heat sink fins cooperate with the cover plate to form a heat dissipation channel.

[0042] In some embodiments, the cover plate is detachably mounted on the outside of the heat dissipation fins of the heat sink or metal plate.

[0043] A battery pack for power tools includes: a housing assembly including at least one metal plate; at least one battery module disposed within the housing assembly, including a plurality of battery cells and having two polarized end faces perpendicular to the longitudinal extension direction of the battery cells; the battery pack further includes: a thermally conductive material fixed to at least a portion of the polarized end faces by coating or bonding and in thermal contact with the metal plate, wherein the thermally conductive material has adhesive properties at least before being fixed to the polarized end faces; the thermally conductive material is configured to conduct heat generated by the battery cells to the metal plate and conduct it out to the external environment through the metal plate.

[0044] In some embodiments, the battery cell connector is further comprising: a cell connector disposed on a polar end face and electrically connected to a battery cell; and a thermally conductive material is fixed to the cell connector by coating or bonding.

[0045] A battery pack for power tools includes: a housing assembly including at least one metal plate; at least one battery module disposed within the housing assembly, including a plurality of battery cells and having two polarized end faces perpendicular to the longitudinal extension direction of the battery cells; the battery pack further includes: thermally conductive adhesive, which covers at least a portion of the polarized end faces and is in thermal contact with the metal plate; the thermally conductive adhesive is configured to conduct heat generated by the battery cells to the metal plate and conduct it out to the external environment through the metal plate.

[0046] A battery pack includes: a housing assembly; at least one battery module disposed within the housing assembly, including a plurality of battery cells; each battery cell includes: a housing, configured as a cylindrical metal shell, having at least an open top; a battery body disposed within the housing, including a first electrode, a second electrode, and a separator located between the first and second electrodes, the first electrode being electrically connected to the housing; and a top cover, sealed and mounted on the top of the housing, and electrically connected to the second electrode; the bottoms of the housings of the plurality of battery cells are arranged to form a first polarized end face of the battery module, and the top covers of the plurality of battery cells are arranged to form a second polarized end face of the battery module; the first polarized end face is configured as a venting surface, through which gas generated by the battery cells within the battery module is discharged; and the second polarized end face is configured as a heat dissipation surface, at least a portion of the second polarized end face being covered with a thermally conductive material for conducting heat generated by the battery module.

[0047] In some embodiments, the first electrode is configured as a positive electrode and the second electrode is configured as a negative electrode.

[0048] In some embodiments, the first electrode is configured as a negative electrode and the second electrode is configured as a positive electrode.

[0049] In some embodiments, the housing assembly forms a sealed cavity.

[0050] In some embodiments, the outer surface of the housing assembly on at least one side is provided with a heat dissipation channel to guide forced convection or natural convection through the heat dissipation channel and to dissipate heat from the battery pack.

[0051] In some embodiments, the thermally conductive material is configured to be in thermal contact with the heat dissipation housing where the heat dissipation channel is located, and a heat dissipation guide portion is formed on the outer surface of the heat dissipation housing on the side away from the battery module.

[0052] In some embodiments, the heat dissipation guide portion cooperates with the inner wall of the battery compartment used to house the battery pack in the power tool to form a heat dissipation channel.

[0053] In some embodiments, the battery pack further includes a cover plate disposed on the outside of the heat dissipation housing, and the heat dissipation guide portion cooperates with the cover plate to form a heat dissipation channel.

[0054] In some embodiments, the heat dissipation guide is a heat dissipation fin formed on the heat dissipation housing.

[0055] In some embodiments, the heat dissipation housing is a metal plate.

[0056] In some embodiments, the thermal conductivity of the heat sink is greater than 0.3 W / (m·K).

[0057] A battery pack includes: a housing assembly; at least one battery module disposed within the housing assembly, comprising a plurality of battery cells and having two polarized end faces perpendicular to the longitudinal extension direction of the battery cells; the battery pack further includes: a venting assembly disposed within the housing assembly, having a venting channel for venting gas; one of the two polarized end faces is a heat dissipation surface, covered with a thermally conductive adhesive that can conduct heat generated by the battery module to an external heat dissipation structure; the other of the two polarized end faces is a venting surface, with the vents of the battery cells arranged on the venting surface facing the air inlet of the venting channel to discharge the gas generated by the battery cells.

[0058] In some embodiments, the heat dissipation surface is the positive terminal of the battery.

[0059] In some embodiments, the heat dissipation surface is the negative terminal of the battery.

[0060] In some embodiments, it further includes: a cell connecting piece disposed on the polarity end face and electrically connected to the battery cell, wherein the cell connecting piece on the exhaust surface has a fuse.

[0061] In some embodiments, it further includes: a cell connecting piece disposed on the polar end face and electrically connected to the battery cell, and a heat insulation sticker is affixed to the cell connecting piece on the exhaust surface.

[0062] In some embodiments, the external heat dissipation structure includes a housing assembly and an external environment, and the thermally conductive material is configured to conduct the heat generated by the battery cell to the housing assembly, and then conduct it out to the external environment through the housing assembly.

[0063] In some embodiments, the housing assembly includes at least one metal plate, and a thermally conductive material is configured to be in thermal contact with the metal plate.

[0064] In some embodiments, the device further includes: a cover plate disposed on the outside of the metal plate; heat dissipation fins are formed on the outer surface of the metal plate on the side away from the battery module, and the heat dissipation fins cooperate with the cover plate to form a heat dissipation channel to guide forced convection or natural convection through the heat dissipation channel and dissipate heat from the battery pack.

[0065] In some embodiments, the outer surface of the housing assembly on at least one side is provided with a heat dissipation channel to guide forced convection or natural convection through the heat dissipation channel and to dissipate heat from the battery pack.

[0066] In some embodiments, the thermally conductive material is configured to be in thermal contact with the heat dissipation housing where the heat dissipation channel is located. A heat dissipation guide portion is formed on the outer surface of the heat dissipation housing away from the battery module. The heat dissipation guide portion cooperates with the inner wall of the battery compartment used to house the battery pack of the power tool to form a heat dissipation channel.

[0067] A battery pack includes: a housing assembly including at least one metal plate; at least one battery module disposed within the housing assembly, including a plurality of battery cells and having two polarized end faces perpendicular to the longitudinal extension direction of the battery cells; one of the two polarized end faces is a heat dissipation surface, at least a portion of which is covered with a thermally conductive material for conducting heat generated by the battery module; the other of the two polarized end faces is an exhaust surface configured to exhaust gas generated by the battery cells within the battery module; and at least a portion of the heat dissipation surface faces the metal plate.

[0068] In some embodiments, the metal plate is made of aluminum or an aluminum alloy.

[0069] In some embodiments, it further includes: a thermally conductive plastic component disposed between the metal plate and the thermally conductive material.

[0070] An electric tool includes: a battery mounting section having a tool terminal, the tool terminal being configured to be electrically connected to the battery terminal of a battery pack for power transmission between the battery pack and the electric tool; the battery pack is the battery pack described in any of the preceding embodiments.

[0071] An electric tool includes: a battery mounting section having tool terminals for electrical connection to battery terminals of a battery pack; a temperature sensor configured to detect the battery temperature of the battery pack and / or ambient temperature; a cooling fan fixed to the electric tool and positioned close to the battery pack, configured to generate convection to dissipate heat from the battery pack; and a controller configured to control the operating mode of the cooling fan based on the battery temperature and ambient temperature.

[0072] In some embodiments, the temperature sensor detects the ambient temperature around the battery pack, as well as detects or acquires the battery temperature inside the battery pack.

[0073] In some embodiments, battery temperature includes the temperature of one or more battery cells inside the battery pack and / or the temperature of the circuit board inside the battery pack.

[0074] In some embodiments, the controller is configured to control the cooling fan to operate in low-speed mode when the battery temperature is less than a first battery temperature threshold and the ambient temperature is greater than or equal to a first ambient temperature threshold.

[0075] In some embodiments, the controller is configured to disable the cooling fan when the battery temperature is below a first battery temperature threshold and the ambient temperature is below a first ambient temperature threshold.

[0076] In some embodiments, the controller is configured to control the cooling fan to operate in medium speed mode when the battery temperature is greater than or equal to a first battery temperature threshold, less than a second battery temperature threshold, and the ambient temperature is greater than or equal to a first ambient temperature threshold.

[0077] In some embodiments, the controller is configured to control the cooling fan to operate in low-speed mode when the battery temperature is greater than or equal to a first battery temperature threshold, less than a second battery temperature threshold, and the ambient temperature is less than a first ambient temperature threshold.

[0078] In some embodiments, the controller is configured to control the cooling fan to operate in high-speed mode when the battery temperature is greater than or equal to a second battery temperature threshold and the ambient temperature is greater than or equal to a first ambient temperature threshold.

[0079] In some embodiments, the controller is configured to control the cooling fan to operate in medium speed mode when the battery temperature is greater than or equal to a second battery temperature threshold and the ambient temperature is less than a first ambient temperature threshold.

[0080] In some embodiments, the battery temperature threshold and / or ambient temperature threshold are based on one or more preset parameters, including battery characteristics, battery pack heat dissipation requirements, and battery pack and / or power tool operating conditions.

[0081] In some embodiments, the controller is configured to shut down the cooling fan when any of the following occurs: the battery temperature is below a shutdown battery temperature threshold; the battery pack is fully charged; or the main unit of the electrical equipment is powered off.

[0082] An electrical device includes: a battery mounting section having device terminals for electrical connection to battery terminals of a battery pack; a temperature sensor configured to detect the battery temperature of the battery pack and / or the ambient temperature; a cooling fan fixed to the electrical device and disposed near the battery pack, configured to generate convection to dissipate heat from the battery pack; and a controller configured to control the operating mode of the cooling fan based on a numerical relationship between the battery temperature and a battery temperature threshold and a numerical relationship between the ambient temperature and an ambient temperature threshold.

[0083] A control method for an electric tool, the electric tool comprising: a battery mounting section having tool terminals for electrical connection to battery terminals of a battery pack; a temperature sensor configured to detect the battery temperature of the battery pack and / or the ambient temperature; a cooling fan fixed to the electric tool and disposed near the battery pack, configured to generate convection to dissipate heat from the battery pack; and a controller configured to execute a control method to control the operation of the cooling fan; wherein the control method comprises: controlling the operating mode of the cooling fan based on a numerical relationship between the battery temperature and a battery temperature threshold and a numerical relationship between the ambient temperature and an ambient temperature threshold. Attached Figure Description

[0084] Figure 1 is a schematic diagram of the battery pack and its adapted electrical equipment in this application.

[0085] Figure 2A is a perspective view of a battery pack as an embodiment of this application;

[0086] Figure 2B is a perspective view of the battery pack shown in Figure 2A from another angle.

[0087] Figure 2C is a plan view of the battery pack shown in Figure 2A from a bottom-view perspective;

[0088] Figure 3A is a three-dimensional view of a portion of the battery pack shown in Figure 2A after disassembly.

[0089] Figure 3B is a three-dimensional view of the battery pack shown in Figure 2A after partial structural decomposition from another perspective.

[0090] Figure 4 is a top view of the exploded structure of the battery pack shown in Figure 2A, including the cover plate, heat dissipation shell, and thermally conductive plastic parts.

[0091] Figure 5A is a cross-sectional view of a battery pack as an embodiment of this application;

[0092] Figure 5B is a partial enlarged view of the cover plate, heat dissipation shell, thermally conductive plastic parts, thermally conductive materials, etc. in the cross-sectional view of the battery pack shown in Figure 5A;

[0093] Figure 6A is a perspective view of a battery pack installed in the battery compartment of an electrical device, as an embodiment of this application.

[0094] Figure 6B is a perspective view of the battery pack and battery compartment of the equipment shown in Figure 6A from another angle.

[0095] Figure 6C is a side view of the battery pack and battery compartment of the electrical equipment shown in Figure 6A;

[0096] Figure 7A is a plan view of the cooling fan inside the battery compartment of an electrical device as an embodiment of this application;

[0097] Figure 7B is a plan view of the cooling fan inside the battery compartment of the electrical device as another embodiment in this application;

[0098] Figure 8 is a cross-sectional view of the battery pack shown in Figure 6A installed in the battery compartment of the electrical equipment.

[0099] Figure 9A is a schematic diagram of a battery cell as an embodiment of this application;

[0100] Figure 9B is a schematic diagram of the top cover connected to the second electrode in the battery cell shown in Figure 9A;

[0101] Figure 9C is a schematic diagram of the outer casing and vent port connected to the first electrode in the battery cell shown in Figure 9A;

[0102] Figure 10 is a perspective view of the battery module and venting assembly in a battery pack according to one embodiment of this application;

[0103] Figure 11A is a perspective view of the battery module and module connecting piece in the battery pack according to one embodiment of this application;

[0104] Figure 11B is a three-dimensional view of the battery module, cell connecting piece, module connecting piece and other structures in the battery pack shown in Figure 11A after being exploded.

[0105] Figure 12 is a perspective view of the cell connecting piece and fuse in the battery pack according to one embodiment of this application;

[0106] Figure 13A is a perspective view of the exhaust surface and heat dissipation surface of the battery module in the battery pack as an embodiment of this application;

[0107] Figure 13B is a three-dimensional view of the battery module, exhaust assembly, thermal conductive material and other structures in the battery pack shown in Figure 13A after being exploded.

[0108] Figure 14 is a schematic diagram of the electrical control principle of the cooling fan of the electrical device as an embodiment of this application;

[0109] Figure 15 is a flowchart of a controller controlling a cooling fan in an electrical device according to one embodiment of this application. Detailed Implementation

[0110] Before explaining any implementation of this application in detail, it should be understood that this application is not limited to its application to the structural details and component arrangements set forth in the following description or shown in the above drawings.

[0111] In this application, the terms "comprising," "including," "having," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0112] In this application, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this application generally indicates that the preceding and following related objects have an "and / or" relationship.

[0113] In this application, the terms "connection," "combination," "coupling," and "installation" can refer to direct connection, combination, coupling, or installation, or indirect connection, combination, coupling, or installation. For example, a direct connection refers to two parts or components being connected together without the need for an intermediary, while an indirect connection refers to two parts or components each being connected to at least one intermediary, with the connection achieved through the intermediary. Furthermore, "connection" and "coupling" are not limited to physical or mechanical connections or couplings, but can also include electrical connections or couplings.

[0114] In this application, those skilled in the art will understand that relative terms (e.g., “about,” “approximately,” “basically,” etc.) used in conjunction with quantities or conditions are to include the values ​​and have the meaning indicated by the context. For example, such relative terms include at least the degree of error associated with the measurement of a particular value, tolerances associated with the particular value due to manufacturing, assembly, use, etc. Such terms should also be considered as disclosing a range defined by the absolute values ​​of the two endpoints. Relative terms may refer to a certain percentage (e.g., 1%, 5%, 10% or more) of the indicated value. Numerical values ​​that do not use relative terms should also be disclosed as specific values ​​with tolerances. Furthermore, “basically” when expressing relative angular relationships (e.g., substantially parallel, substantially perpendicular) may refer to a certain degree (e.g., 1 degree, 5 degrees, 10 degrees or more) added to or subtracted from the indicated angle.

[0115] In this application, those skilled in the art will understand that the function performed by a component can be performed by one component, multiple components, one part, or multiple parts. Similarly, the function performed by a part can also be performed by one part, one component, or a combination of multiple parts.

[0116] In this application, the directional terms "upper," "lower," "left," "right," "front," and "rear" are used to describe the orientation and positional relationships shown in the accompanying drawings and should not be construed as limiting the embodiments of this application. Furthermore, in the context, it should be understood that when an element is mentioned as being connected "upper" or "lower" to another element, it can be directly connected to the other element "upper" or "lower," or indirectly connected through an intermediate element. It should also be understood that directional terms such as upper side, lower side, left side, right side, front side, and rear side not only represent positive orientation but can also be understood as lateral orientation. For example, "below" can include directly below, lower left, lower right, lower front, and lower rear.

[0117] In this application, the terms "controller," "processor," "central processing unit," "CPU," and "MCU" are used interchangeably. When using the unit "controller," "processor," "central processing unit," "CPU," or "MCU" to perform a specific function, unless otherwise stated, these functions may be performed by a single or multiple of the aforementioned units.

[0118] In this application, the terms "device," "module," or "unit" are used to describe devices that can be implemented in hardware or software to perform a specific function.

[0119] In this application, the terms “calculation,” “judgment,” “control,” “determine,” “identify,” etc., refer to the operation and process of a computer system or similar electronic computing device (e.g., controller, processor, etc.).

[0120] The benefits, other advantages, and solutions to problems will be described below with reference to specific embodiments. However, these benefits, advantages, solutions to problems, and any features that may lead to or make any benefit, advantage, or solution appear or become more significant should not be construed as key, essential, or necessary features of any or all claims.

[0121] With the development of lithium battery technology, it has been widely used in various industries. A major focus in its design is safety, which includes both cell-level and overall pack-level safety. This requires attention to both microscopic aspects such as the materials of the positive and negative electrodes of the cells and macroscopic aspects such as heat dissipation, temperature uniformity, drop protection, and water immersion protection of the entire battery pack. Among these, the design related to thermal runaway of the battery pack is of paramount importance, and this is no exception in power tool battery packs. In related technologies, taking a ride-on lawnmower as an example, its battery pack heat dissipation mainly relies on natural heat dissipation through openings in the outer casing. However, with the improvement of power and other performance indicators of power tools, the effectiveness of this design is insufficient, which is detrimental to the battery pack's performance and lifespan.

[0122] The technical solutions proposed in this application will be described in detail below with reference to specific embodiments and accompanying drawings.

[0123] This application primarily proposes a battery pack for power tools and compatible power tools, chargers, and other electrical equipment. The solution mainly aims to improve the battery pack's heat dissipation, temperature equalization, explosion-proof pressure relief, and other functions to enhance its safety. The aforementioned electrical equipment 200 has a battery mounting portion 210 for coupling with the battery pack 100, and the battery mounting portion 210 may contain device terminals 211. For example, the battery mounting portion 210 of the power tool 201 contains a tool terminal 211, and the battery mounting portion 210 of the charger 202 contains a charging terminal 211. The battery pack 100 is detachably connected to the electrical equipment 200. When the battery pack 100 is installed into the battery mounting portion 210 of the electrical equipment 200 by means of insertion or other methods, the battery terminals 125 on the battery pack 100 side can be coupled and electrically connected to the aforementioned tool terminals 211, charging terminals 211, and other device terminals 211 to conduct power transmission between the two. This includes situations where, when electrically connected to the power tool 201, the battery pack 100 supplies power to the power tool 201, enabling it to perform tasks such as cutting and moving; and when electrically connected to the charger 202, adapter, etc., the charger 202 supplies power to the battery pack 100, allowing the battery pack 100 to store energy for later discharge. The structural configurations of the power tool 201, charger 202, adapter, and other electrical devices 200 are not specifically limited without interfering with the implementation of the subsequent scheme.

[0124] Referring to Figure 1, the battery pack 100 in this application can be adapted to various types of power tools 201, including but not limited to the ride-on lawnmower 201a, electric drill 201b, chainsaw 201c, hair dryer 201d, and all-terrain vehicle 201e shown in Figure 1. In some embodiments, the power tools 201 adapted to the battery pack 100 may include handheld tools, such as pruning shears and circular saws. In some embodiments, the power tools 201 adapted to the battery pack 100 may include benchtop tools, such as miter saws and metal cutters. In some embodiments, the power tools 201 adapted to the battery pack 100 may include ride-on tools and / or push tools, such as push lawnmowers, push snow sweepers, ride-on lawnmowers, and stand-up lawnmowers. In some embodiments, the power tools 201 adapted to the battery pack 100 may include outdoor wheeled tools, such as multi-purpose wheeled garden tools and outdoor electric vehicles such as farm vehicles and golf carts. In some embodiments, the power tool 201 adapted to the battery pack 100 may include robotic tools, such as lawnmowers, snowplows, etc. Alternatively, in some embodiments, the power tool 201 may be garden tools, including pruning machines, lawn mowers, hair dryers, lawn mowers, etc. In some embodiments, the power tool 201 may be decorating tools, including screwdrivers, nail guns, glue guns, sanders, etc. In some embodiments, the power tool 201 may be cleaning tools, including hair dryers, snowplows, washing machines, etc. In some embodiments, the power tool 201 may be cutting tools, including reciprocating saws, jigsaws, circular saws, chainsaws, etc. In some embodiments, the power tool 201 may be fastening tools, including electric drills, screwdrivers, hammer drills, etc. In some embodiments, the power tool 201 may be grinding tools, including angle grinders, sanders, etc. In some embodiments, the power tool 201 may also be other tools, such as lights, fans, etc. It is understood that, without contradicting the features, the power tools 201 adapted to the battery pack 100 of this application may also include more types not shown above.

[0125] First, the basic structural composition of the battery pack 100 in this application will be described. Referring to Figures 2A to 5B, the (power tool) battery pack 100 will include at least a housing assembly 110 and a battery module 120. The housing assembly 110 constitutes the main body of the battery pack 100, and has an internal receiving space, within which the battery module 120 is disposed. The number of battery modules 120 within the battery pack 100 can be one or more, and these modules can be connected in series, in parallel, or in a mixed series-parallel configuration. Each battery module 120 may include multiple battery cells 121, i.e., multiple battery cells 121. The multiple battery cells 121 within the same battery module 120 can be connected in series, in parallel, or in a mixed series-parallel configuration; this application does not impose specific limitations on this. The multiple battery cells 121 within the same battery module 120 can be arranged substantially parallel, for example, their respective longitudinal extension directions 1202 are substantially parallel to each other. The battery module 120 has two polarized end faces 1201 perpendicular to the longitudinal extension direction 1202 of the battery cells 121. In some embodiments, the battery cells 121 can be cylindrical cells, and the two polarized end faces 1201 of a battery module 120 can be composed of the two axial end faces of multiple cylindrical cells within the module. It should be noted that although the multiple battery cells 121 within the battery module 120 are arranged in parallel, the orientation of the positive and negative electrodes of each battery cell 121 may not necessarily be the same, and the electrodes located on the same polarized end face 1201 of the battery module 120 may not all be cell electrodes of the same polarity. The specific situation may be related to the connection relationship between the battery cells 121.

[0126] In one alternative embodiment of this application, referring to Figures 2A to 8, to improve the thermal management of the battery pack 100, a heat dissipation channel 111a is provided on at least one side of the outer surface of the housing assembly 110 of the battery pack 100 to guide forced convection and / or natural convection flow through the heat dissipation channel 111a and dissipate heat from the battery pack 100. Specifically, at least a portion of the outer surface of the housing of the battery pack 100 is provided with heat dissipation channels 111a, the number of which may not be unique and have airflow inlets 1111 and airflow outlets 1112. In some embodiments, the heat dissipation channels 111a may be directly formed on the outer wall of the housing. In some embodiments, the heat dissipation channels 111a may be sealed except for the airflow inlets and outlets. Forced convection gas driven by external forces such as fans, or natural convection gas caused by temperature / density differences, can enter the heat dissipation channel 111a through the airflow inlet 1111. It travels within the heat dissipation channel 111a, carrying away heat from the outer surface of the battery pack 100 casing, and then exits through the airflow outlet 1112, thereby dissipating heat from the battery pack 100. In this embodiment, the heat dissipation channel 111a is primarily designed to guide forced convection gas, but the passage of naturally convective gas within it is not excluded.

[0127] In some embodiments, as shown in Figures 3A and 5A, a heat dissipation guide portion 111b is formed on at least one side of the outer surface of the housing assembly 110. The guidance of forced convection or natural convection gas is mainly achieved by the heat dissipation guide portion 111b. Hereinafter, the housing of the battery pack 100 where the heat dissipation guide portion 111b or heat dissipation channel 111a is located will be referred to as the heat dissipation housing 111. In some embodiments, the heat dissipation housing 111 may include at least one side of the housing assembly 110 that is substantially parallel to the polar end face 1201 of the battery module 120. There are various options for the specific form of the heat dissipation guide portion 111b on the outer wall of the heat dissipation housing 111. For example, it may be multiple open slots formed on the outer wall of the housing, with their slot openings facing outward away from the battery module 120 and airflow inlets and outlets 1111 and 1112 on the side not opposite to the slot openings, and they may be arranged parallel to each other with varying density. In some embodiments, the heat dissipation channel 111a is formed by multiple heat dissipation fins 111b on the outer wall of the housing; that is, the heat dissipation guide portion 111b is formed by multiple heat dissipation fins 111b on the outer side of the heat dissipation housing 111. The plane containing the heat dissipation fins 111b may be substantially perpendicular to or obliquely intersecting the plane containing the heat dissipation housing 111. The spacing and / or depth of the heat dissipation fins 111b have a significant impact on their heat dissipation effect. In some embodiments, the fins are parallel to each other, and the spacing between the heat dissipation fins 111b can be greater than or equal to 3 mm and less than or equal to 8 mm. In some embodiments, the fins are substantially perpendicular to the outer wall of the housing, and the fin depth of the heat dissipation fins 111b is greater than or equal to 10 mm and less than or equal to 20 mm. Further, in some embodiments, the spacing between the heat dissipation fins 111b is not unique, and the spacing between adjacent heat dissipation fins 111b at different positions on the heat dissipation housing 111 is at least partially different. Preferably, the spacing of the heat dissipation fins 111b at different locations can be adaptively adjusted based on the test or simulation results of the battery pack 100 or battery module 120. More dense heat dissipation fins 111b can be placed in locations where heat accumulation is concentrated, and the fin spacing can be reasonably reduced. Conversely, relatively sparse heat dissipation fins 111b can be placed in locations with lower temperatures, and the fin spacing can be relatively increased.

[0128] The heat dissipation guides 111b, such as open slots or heat dissipation fins 111b, formed on the outer wall of the battery pack 100 housing can be directly regarded as heat dissipation channels 111a for forced or natural convection. However, in this case, since the heat dissipation channel 111a is mostly connected to the outside and is basically in an open state, the improvement in heat dissipation effect is relatively limited. Therefore, it is further proposed that in some embodiments, the aforementioned heat dissipation channel 111a of the battery pack 100 can be formed by the heat dissipation housing 111 and its heat dissipation guides 111b in conjunction with other components. The heat dissipation channel 111a formed is basically sealed except for its airflow inlet 1111 and airflow outlet 1112. Convective gas will enter a relatively limited space, thereby enabling it to quickly and efficiently dissipate heat within the channel. Practice has shown that such a design has a more significant improvement in various aspects of performance.

[0129] In one implementation, as shown in Figures 6A to 8, the aforementioned heat dissipation channel 111a of the battery pack 100 can be formed by the heat dissipation guide portion 111b on its heat dissipation housing 111 cooperating with the inner wall of the battery compartment 210a in the electrical device 200 that houses the battery pack 100. When the battery pack 100 is placed in the battery compartment 210a of the electrical device 200, forced convection or natural convection gas will flow through the heat dissipation channel 111a formed by the cooperation between the inner wall of the battery compartment 210a and the heat dissipation guide portion 111b, and dissipate heat from the battery pack 100. In some embodiments, the shape of the battery compartment 210a itself and its relative position to the battery pack 100 are not limited; the heat dissipation effect can be improved simply by the inner wall of the battery compartment 210a constricting the space near the heat dissipation guide portion 111b. Furthermore, in some embodiments, the battery compartment 210a of the electrical device 200 has at least one inner wall facing and substantially parallel to the heat dissipation housing 111, so as to form a heat dissipation channel 111a with better heat dissipation effect with the heat dissipation housing 111 of the housed battery pack 100. In some embodiments, the battery compartment 210a has structures such as clips for fixing and cooperating to form the heat dissipation channel 111a.

[0130] In some embodiments, as shown in Figures 6B to 8, the electrical device 200 that cooperates with the heat dissipation guide portion 111b on the outer wall of the battery pack 100 housing to form a heat dissipation channel 111a includes a power tool 201 and a charger 202. The power tool 201 or charger 202 has a built-in cooling fan 220. The forced convection gas driven by the cooling fan 220 can flow through the heat dissipation channel 111a within the battery compartment 210a to dissipate heat from the battery pack 100. In some embodiments, it is not excluded that the electrical device 200 has more than one battery compartment 210a. Multiple battery packs 100 can be assembled in different battery compartments 210a. Each battery pack 100 can have its own corresponding battery compartment 210a, or some battery packs 100 can share a single battery compartment 210a. Furthermore, as shown in Figures 7A and 7B, one cooling fan 220 or multiple cooling fans 220 can be provided within a battery compartment 210a. In some embodiments, the battery compartment 210a and the battery pack 100 may be in a one-to-one relationship, and / or the cooling fan 220 and the battery pack 100 may be in a one-to-one relationship. In some embodiments, the cooling fan 220 is fixed to the bottom of the battery mounting portion 210 of the electrical device 200, for example, the bottom of the battery compartment 210a, so as to correspond to the airflow opening of the heat dissipation channel 111a of the battery pack 100 placed in the battery compartment 210a, thereby allowing the air-cooled airflow to smoothly enter the channel. In some embodiments, the cooling fan 220 will drive forced convection to flow from top to bottom through the heat dissipation channel 111a to dissipate heat from the battery pack 100, which has a good heat dissipation effect and can prevent grass clippings, dust, wood chips, etc. from being brought into the battery pack 100. If the cooling fan 220 is located at the bottom of the battery mounting portion 210, that is, below the battery pack 100, the cooling fan 220 will perform a suction action. In some embodiments, a protective net 113 is provided above the cooling fan 220 of the electrical device 200 to prevent foreign objects from entering and interfering with the cooling fan 220. Alternatively, the battery pack 100 also includes a protective net 113 disposed at the bottom of the battery pack 100. Exemplarily, the protective net 113 is detachably installed outside the bottom housing of the battery pack 100. In some embodiments, the battery pack 100 includes a protective net 113 disposed relative to the airflow inlet 1111 and / or airflow outlet 1112 of the heat dissipation channel 111a. The protective net 113 can be detachably installed to the outer shell of the battery pack 100 by means of attachment or snap-fit, which can prevent foreign objects from entering the battery pack 100 and is easy to disassemble and clean. In some embodiments, a protective net or baffle is also provided below the cooling fan 220 of the electrical device 200.

[0131] In another implementation, as shown in Figures 2A to 5B, the battery pack 100 further includes a cover plate 112. The aforementioned heat dissipation channel 111a of the battery pack 100 can be formed by the heat dissipation guide portion 111b on its heat dissipation housing 111 cooperating with the cover plate 112. The cover plate 112 can be located outside the heat dissipation housing 111. For example, the plane of the cover plate 112 can be substantially parallel to the plane of the heat dissipation housing 111. When the cover plate 112 is installed on the battery pack 100, forced convection or natural convection gas will flow through the heat dissipation channel 111a formed by the cover plate 112 and the heat dissipation guide portion 111b to dissipate heat from the battery pack 100. In some embodiments, the cover plate 112 of the battery pack 100 is a detachable component, which can be removed and installed outside the heat dissipation housing 111 where the heat dissipation guide portion 111b, such as the heat dissipation fins 111b, is located, to facilitate maintenance of the cover plate 112 and the heat dissipation channel 111a between it and the heat dissipation housing 111. A snap-fit ​​structure may also be provided between the two. Thus, regardless of whether the outer side of the heat dissipation housing 111 of the battery pack 100 is fitted with the inner wall of the battery compartment 210a or whether the fit of the inner wall of the battery compartment 210a is appropriate, even when applied to different scenarios and different electrical devices, a heat dissipation channel 111a with a suitable cross section can be formed, so that the heat dissipation and safety performance of the relevant design can be kept at a good level.

[0132] In another implementation, the battery pack 100 includes a cover plate 112, the inner wall of which cooperates with the heat dissipation guide portion 111b on the outer wall of the battery pack 100 housing to form a heat dissipation channel. Simultaneously, the battery pack 100 is also housed within the battery compartment 210a of the electrical device 200, the inner wall of which also cooperates with the heat dissipation guide portion 111b to form a heat dissipation channel. The heat dissipation channel formed with the cover plate 112 is within the heat dissipation channel formed with the battery compartment 210a; for example, the heat dissipation channel formed with the cover plate 112 can pass through the heat dissipation channel formed with the battery compartment 210a. This implementation combines the two solutions described above. Even after the battery pack 100 is detached from the electrical device 200 with the battery compartment 210a, it can still maintain good heat dissipation performance through the air duct formed by the cover plate 112. When installed in the electrical device 200 with the battery compartment 210a, the cover plate 112 can be removed, or the cover plate 112 can be used to divide the channel cross-section. Different implementation methods or the switching and combination of different implementation methods are intended to obtain a better heat dissipation channel that works better with wind speed and wind pressure under forced convection conditions.

[0133] It is understood that in the above embodiments, the heat dissipation guiding portion 111b, such as the heat dissipation fins 111b, is formed on the outer wall of the battery pack 100 housing, which is more effective. However, if the heat dissipation guiding portion, such as the heat dissipation fins, is disposed on the inner wall of the battery compartment 210a or the inner wall of the cover plate 112, the heat dissipation channel 111a for guiding convection can also be formed by the cooperation between the outer wall of the battery pack 100 housing and the heat dissipation guiding portion on the inner wall of the battery compartment 210a or the inner wall of the cover plate 112. This alternative solution should still be considered within the scope of this invention. Furthermore, in addition to directly forming a channel by the heat dissipation fins on the housing and the inner wall of the battery compartment or cover plate, the heat dissipation channel 111a can also be formed by making a shape on the inner wall of the battery compartment or cover plate that matches other types of heat dissipation guiding portions.

[0134] In some embodiments, the heat dissipation channel 111a described above is provided or formed in the heat dissipation housing 111 in the housing assembly 110. The heat dissipation housing 111 can be a metal plate, or in other embodiments, the heat dissipation housing 111 can be a heat dissipation plate with a thermal conductivity greater than 0.3 W / (m·K). In some embodiments, the heat dissipation housing 111 can be made of aluminum or aluminum alloy.

[0135] In some embodiments, the housing assembly 110 forms a sealed cavity, and the battery module 120 is disposed within this sealed cavity. The battery pack 100 housing is designed to form a sealed receiving cavity, and core components such as the battery module 120 related to power supply are arranged within this sealed cavity to isolate the internal and external environments of the battery pack 100, avoid interference from external water and dust, and also facilitate fire prevention and flame retardancy. However, given the sealed housing, the solution of opening heat dissipation holes on the battery pack 100 housing for natural heat dissipation or air cooling in related technologies is no longer applicable, while the method of providing heat dissipation channels 111a on the outer wall of the battery pack 100 housing described above can be well applied in this scenario. However, it is understood that the battery pack 100 can still be equipped with explosion-proof pressure relief devices, which can perform air pressure balance or gas exchange inside and outside the battery pack 100. The sealed cavity described here refers to the internal space of the battery pack 100 being sealed in a state where there is no internal or external gas-liquid balance / exchange, and no air or liquid leakage occurs.

[0136] Following the foregoing, in another alternative embodiment of this application, to improve battery pack thermal management, the housing assembly 110 of the battery pack 100 forms a sealed cavity, within which the battery module 120 is disposed. Furthermore, a heat dissipation channel 111a is provided on at least one side of the outer surface of the housing assembly 110. This heat dissipation channel 111a guides forced convection flow across the outer surface of the battery pack 100 housing to dissipate heat from the battery pack 100. For example, a longitudinal heat dissipation channel 111a is provided on at least one side of the outer surface of the housing assembly 110. This longitudinal heat dissipation channel 111a guides forced convection flow from top to bottom across the outer surface of the battery pack 100 housing to dissipate heat from the battery pack 100. The battery pack 100 is sealed, and its outer wall has a longitudinal heat dissipation channel 111a that guides forced convection from top to bottom through the outer wall of the battery pack 100 for heat dissipation. That is, forced convection driven by a fan or similar device utilizes the heat dissipation channel 111a on the outer wall of the sealed battery pack 100 to perform air cooling from top to bottom. The airflow inlet 1111 is at the top, and the airflow outlet 1112 is at the bottom. This arrangement specifically adapts to the coordinated needs of the power tool battery pack 100 in terms of thermal safety, structural layout, and other aspects, conforming to convection laws and providing better heat dissipation efficiency and uniformity. However, in other embodiments, the heat dissipation channel 111a can also be non-longitudinal, for example, it can be transverse. That is, the direction of forced convection guided by the heat dissipation channel 111a can also be non-top to bottom, for example, it can be left-right or front-back. Alternatively, for example, assuming a battery pack 100 as shown in Figure 8 is placed in a horizontally oriented battery compartment 210a, or is horizontally attached to and detached from an electrical device 200, the heat dissipation channel 111a of the battery pack 100 is a transverse heat dissipation channel 111a. Alternatively, the specific direction of the heat dissipation channel 111a may correspond to the direction of the fan driving forced convection; the fan's rotation plane may be in a position approximately parallel to the horizontal plane or in a position approximately perpendicular to the horizontal plane. These variations should be understood by those skilled in the art. In some embodiments, a (longitudinal) heat dissipation channel 111a or a heat dissipation guide 111b may be directly formed on the outer wall of the battery pack 100 housing; or, the (longitudinal) heat dissipation channel 111a on the outer surface of the battery pack 100 housing may be formed by a heat dissipation guide 111b, such as a heat dissipation fin 111b, in conjunction with the inner wall of a cover plate 112 or the inner wall of the battery compartment 210a in an electrical device 200 such as a power tool 201 or charger 202 that houses the battery pack 100. In some embodiments, the heat dissipation housing 111 where the (longitudinal) heat dissipation channel 111a is located is the housing closest to the polar end face 1201 where the cell electrode is located, and the plane where the heat dissipation housing 111 is located can be substantially parallel to the polar end face 1201.In some embodiments, the extending direction of the (longitudinal) heat dissipation channel 111a provided outside the heat dissipation housing 111 may intersect or be opposite to the longitudinal extending direction 1202 of the battery cell 121. For example, the extending direction of the longitudinal heat dissipation channel 111a may be perpendicular to the longitudinal extending direction 1202 of the battery cell 121. In some embodiments, the extending direction of the longitudinal heat dissipation channel 111a may intersect with the support surface of the battery pack 100, or may be substantially perpendicular to the support surface of the battery pack 100, while the longitudinal extending direction 1202 of the battery cell 121 may be parallel to the support surface of the battery pack 100. Other specific embodiments described above and below can also be combined with this embodiment to comprehensively optimize the thermal management of the battery pack.

[0137] Following the foregoing, in another alternative embodiment of this application, in order to improve the thermal management of the battery pack, the housing assembly 110 of the battery pack 100 is formed with a sealed cavity, and the battery module 120 is disposed in the sealed cavity. At the same time, a heat dissipation channel 111a is provided on the outer surface of the housing assembly 110 on at least one side to guide forced convection and / or natural convection to flow through the heat dissipation channel 111a and dissipate heat from the battery pack 100. The housing in which the heat dissipation channel 111a is located is made of a metal plate 111. Specifically, taking the heat dissipation guide portion 111b directly formed on the outer wall of the battery pack 100 housing to realize the aforementioned heat dissipation channel 111a as an example, the heat dissipation housing 111 where the heat dissipation guide portion 111b, such as the heat dissipation fins 111b, is located can be made of a metal plate 111. That is, at least a portion of the outer wall of the metal housing of the battery pack 100 can be formed with open grooves or heat dissipation fins 111b, etc. The heat dissipation performance of metal is better than that of other materials, and it is easy to realize the aforementioned heat dissipation guide portion 111b through manufacturing processes, thereby further improving the heat dissipation and temperature uniformity of the battery pack 100. In some embodiments, the metal plate 111 in the housing assembly 110 is made of aluminum or aluminum alloy. Other specific embodiments described above and below can also be combined with this embodiment to comprehensively optimize the thermal management of the battery pack.

[0138] Correspondingly, this application also proposes a heat dissipation optimization scheme based on the metal casing of the battery pack 100. Similar to the above, the battery pack 100 includes a casing assembly 110 and a battery module 120 disposed within the casing assembly 110. The battery module 120 includes multiple battery cells 121 and has two polar end faces 1201 perpendicular to the longitudinal extension direction 1202 of the battery cells 121. Meanwhile, the casing assembly 110 of the battery pack 100 includes at least one metal plate 111, and a thermally conductive material 122 is disposed inside the pack, at least partially covering the polar end faces 1201 and in thermal contact with the metal plate 111. The heat generated by the battery cells 121 within the battery module 120 is conducted from the polar end faces 1201 to the metal plate 111 through the thermally conductive material 122 covering them, and then discharged to the external environment through the metal plate 111.

[0139] The thermally conductive material 122 has adhesive properties at least before being fixed to the polar end face 1201. The adhesive properties of the material here refer to the material surface being fixed to other substances through physical or chemical forces (adhesive adhesion, curing adhesion, pressure fixation, pre-formed thermal pads, etc.). It may include thermally conductive adhesive, thermally conductive double-sided tape, phase change material, thermally conductive silicone grease, thermally conductive gel, thermally conductive pads, etc. The type selection can be specifically adjusted according to the thermal conductivity requirements and adhesion strength. The thermally conductive material 122 can be fixed to the polar end face 1201 by coating or bonding. It can effectively conduct the heat generated by the battery cell 121 to the outside, and the thermally conductive material 122 can also provide sealed and waterproof protection for the cell electrodes located on the polar end face 1201.

[0140] In some embodiments, the thermal contact between the thermally conductive material 122 covering the polar end face 1201 and the metal plate 111 can be a direct physical contact between the thermally conductive material 122 and the metal plate 111 for heat conduction. The heat generated by the battery cell 121 can be directly conducted to the metal plate 111 through the thermally conductive material 122 and then quickly conducted to the outside. That is, the heat conduction path is polar end face 1201 - thermally conductive material 122 - metal plate 111 - outside air. Alternatively, other materials or components can be sandwiched between the thermally conductive material 122 and the metal plate 111. However, the heat dissipation path from the thermally conductive material 122 to the metal plate 111 is mainly heat conduction rather than heat convection or heat radiation. For example, there can be no air gap between the thermally conductive material 122 and the metal plate 111 at least at the cell electrode. Even if there are other materials or components between the thermally conductive adhesive 122 and the metal plate 111, they can be sandwiched between the thermally conductive material 122 and the metal plate 111 in a tightly fitted manner. In some embodiments, as shown in Figures 4 to 5B, a thermally conductive plastic component 123 is also provided between the thermally conductive material 122 or thermally conductive adhesive 122 and the metal plate 111. Since the thermally conductive material 122 directly covers the polar end face 1201, for example, it is coated on the battery cell electrode. The metal plate 111 being directly added to the outside of the thermally conductive material 122 may pose a risk of leakage. By adding a thermally conductive plastic component 123 between the two, the thermal conduction path will not be excessively lengthened, and insulation can be ensured. At this time, the thermal conduction path is polar end face 1201 - thermally conductive material 122 - thermally conductive plastic component 123 - metal plate 111 - external air. For example, the thermally conductive plastic component 123 can be attached to the inner wall of the metal plate 111 and can be made thinner.

[0141] In some embodiments, an oxide layer is formed on the surface of the metal plate 111, and the heat dissipation, insulation, corrosion resistance, hardness and other properties of the metal plate 111 are further improved by metal anodizing and other treatments. In some embodiments, the metal plate 111 is made of aluminum or an aluminum alloy.

[0142] In some embodiments, as shown in FIG8, the battery pack 100 further includes a support assembly 130, namely a cell support 130, which is housed inside the housing assembly 110 like the battery module 120, and can support the battery module 120 within the housing assembly 110. For example, the support assembly 130 has a plurality of support slots corresponding to the battery cells 121 in the battery module 120. There can be a one-to-one correspondence between the support slots and the cells, and the depth of each support slot can be different to adjust the contact area between the cells and the support in each support slot, so as to adapt to the heat accumulation density at different locations in the battery module 120, thereby improving the problem of excessive temperature difference at different locations in the battery pack 100. In some embodiments, the aforementioned bracket assembly 130 is at least partially made of a material with variable thermal conductivity to adapt to different heat dissipation requirements at different temperatures during the charging and discharging of the power tool battery pack 100. For details on the specific implementation of the battery cell bracket in the power tool battery pack made of a material with variable thermal conductivity, please refer to or partially refer to the description in Chinese Patent Application No. 202410200263.0 filed by the applicant.

[0143] In some embodiments, a screw penetrating the battery module 120 of the battery pack 100 may be provided at the location where heat accumulation is relatively concentrated. For example, the screw may be provided to penetrate the module between the battery cells to conduct heat that is difficult to escape from inside the battery module 120 to the thermally conductive material 122 and the metal plate 111. Exemplarily, the extension direction of the screw may be substantially perpendicular to the plane where the polar end face 1201 or the metal plate 111 is located, that is, the extension direction of the screw may be substantially parallel to the longitudinal extension direction of the battery cell 121 in the battery module 120. In some embodiments, at least one end of the screw may abut against the metal plate 111. In some embodiments, the screw is made of a material with high thermal conductivity.

[0144] In some embodiments, the minimum spacing between each battery cell 121 in the battery pack 100 is greater than or equal to 3 mm, so as to minimize the influence between the battery cells 121 without compromising the advantages such as compact structure, and to avoid thermal runaway caused by heat accumulation.

[0145] In some embodiments, the thickness of the thermally conductive material 122, such as the thermally conductive adhesive 122, covering the polar end face 1201 is not uniform. It can be adaptively adjusted based on the test or simulation results of the battery pack 100. The adhesive is applied thinner in the high-temperature area where heat accumulates and thicker in the low-temperature area, thereby adaptively adjusting the length of the heat conduction path from the cell to the metal plate 111, improving the consistency of heat dissipation efficiency and temperature uniformity.

[0146] In some embodiments, the housing assembly 110 of the battery pack 100 has a heat dissipation channel 111a on at least the outer surface of the metal plate 111. A cooling fan 220 is provided inside the electrical device 200, such as the power tool 201 or charger 202. The airflow generated by the fan flows through the heat dissipation channel 111a and carries away the heat conducted to the metal plate 111 by the thermally conductive material 122 or thermally conductive adhesive 122. Heat conduction is mainly performed inside the metal plate 111 of the battery pack 100, while heat convection is mainly performed outside the metal plate 111. In some embodiments, heat dissipation fins 111b are formed or connected to the outer surface of the metal plate 111 on the side away from the battery module 120. The heat dissipation fins 111b cooperate with the inner wall of the battery compartment 210a used to house the battery pack 100 in the electrical device 200, such as the power tool 201 or charger 202, to form the heat dissipation channel 111a. In some embodiments, the battery pack 100 further includes a cover plate 112 disposed on the outside of the metal plate 111, and heat dissipation fins 111b formed or connected on the outer surface of the metal plate 111 away from the battery module 120 cooperate with the cover plate 112 to form the heat dissipation channel 111a.

[0147] Alternatively, the solution of external heat dissipation channel 111a of the battery pack 100 housing described in any one or more of the preceding embodiments can be combined with the solution of adding thermally conductive material 122 to the metal plate 111. The heat generated on the polar end face 1201 of the battery module 120 inside the battery pack 100 can be conducted to the heat dissipation housing 111 or metal plate 111 through the thermally conductive adhesive 122 with a shorter path and higher efficiency. Then, it is quickly carried away to a more distant external environment by the forced convection or natural convection gas within the heat dissipation channel 111a of the heat dissipation housing 111 or metal plate 111. This will comprehensively optimize the heat dissipation, temperature uniformity, waterproof protection, and other performance aspects of the power tool battery pack 100 in this application. It is understood that when combined with the aforementioned heat dissipation channel 111a solution, even if the heat dissipation housing 111 is not a metal plate 111, significant performance optimization of the battery pack 100 should still be achieved.

[0148] In one embodiment, the metal plate 111 can also be replaced by a heat sink 111 with a thermal conductivity greater than 0.3 W / (m·K). That is, the battery pack 100 includes a housing assembly 110 and a battery module 120 disposed within the housing assembly 110. The battery module 120 includes multiple battery cells 121 and has two polar end faces 1201 perpendicular to the longitudinal extension direction 1202 of the battery cells 121. Simultaneously, the housing assembly 110 of the battery pack 100 includes at least one heat sink 111, and the pack also contains a thermally conductive material 122 that at least partially covers the polar end faces 1201 and is in thermal contact with the metal plate 111. The thermal conductivity of the heat sink 111 is greater than 0.3 W / (m·K). Alternatively, in some embodiments, the thermal conductivity of the heat sink 111 is greater than or equal to 0.5 W / (m·K). In some embodiments, the thermal conductivity of the heat sink 111 is greater than or equal to 0.8 W / (m·K). In some embodiments, the thermal conductivity of the heat sink 111 is greater than or equal to 1 W / (m·K). In some embodiments, the thermal conductivity of the heat sink 111 is greater than or equal to 3 W / (m·K). In some embodiments, the thermal conductivity of the heat sink 111 is greater than or equal to 5 W / (m·K). In some embodiments, the heat sink 111 comprises a metal plate 111. In some embodiments, the heat sink 111 comprises modified engineering plastics with good thermal conductivity, etc. The heat generated by the battery cells 121 in the battery module 120 is conducted from the polar end face 1201 through the thermally conductive material 122 covering it to the heat sink 111, and then discharged to the external environment through the heat sink 111. The other embodiments described above can be combined with this embodiment to comprehensively optimize the battery pack.

[0149] Correspondingly, as shown in Figures 1 and 6A to 8, this application also proposes an electrical device 200 adaptable to the battery pack 100 described above, which may include a battery mounting portion 210 and a cooling fan 220. The battery mounting portion 210 has a device terminal 211 capable of being electrically coupled to the battery terminal 125 of the battery pack 100 for power transmission between them. The cooling fan 220 is fixed in the electrical device 200 near the battery pack 100 and can drive forced convection flowing through the heat dissipation channel 111a of the battery pack 100. The heat dissipation channel 111a of the battery pack 100 may be formed by its heat dissipation guide portion 111b cooperating with a cover plate 112, or it may be formed by cooperating with the inner wall of the battery compartment 210a of the electrical device 200. In some embodiments, the electrical device 200 may include a power tool 201 and / or a charger 202. Furthermore, the power tool 201, which is the electrical equipment 200, may include one or more of the following: push-type working machine, riding-type working machine, self-propelled working machine, and wheeled working machine. For example, it may be a push-type lawnmower, riding-type lawnmower, standing lawnmower, push-type snow sweeper, all-terrain vehicle (ATV, UTV), etc.

[0150] In some embodiments, the battery mounting portion 210 of the electrical device 200 can form a battery compartment 210a, in which the battery pack 100 is housed. During installation, at least the bottom of the battery pack 100 will not be exposed relative to the battery compartment 210a, or the battery pack 100 may be completely housed within the battery compartment 210a. In some embodiments, the battery mounting portion 210 of the electrical device 200 may be open or semi-open, with the battery pack 100 detachably connected to it via a plug-in or similar method. The battery mounting portion 210 only needs to couple with the battery terminals 125 of the battery pack 100 and securely connect to and fix the battery pack 100. In some embodiments, as shown in Figures 6A to 6C, a cooling fan 220 may be located at the bottom of the battery mounting portion 210 of the electrical device 200, for example, at the bottom of the battery compartment 210a or at one end of the battery mounting portion 210. When the battery pack 100 is installed into the battery mounting section 210 of the electrical device 200, the airflow port of the heat dissipation channel 111a provided on the outside of the battery pack 100 housing can face the bottom of the battery mounting section 210, so that the forced convection driven by the cooling fan 220 can pass more smoothly through the heat dissipation channel 111a.

[0151] In some embodiments, a protective net 113 is provided above the cooling fan 220 of the electrical device 200, or a protective net 113 is provided at the bottom of the battery pack 100, to prevent foreign objects from entering the electrical device 200 with the airflow. Specifically, when the battery pack 100 is installed in the battery mounting section 210 of the electrical device 200, the battery pack 100, the protective net 113, the cooling fan 220, and other internal structures of the electrical device 200 are arranged sequentially along its installation direction. That is, the battery pack 100 is located above or outside the protective net 113, and the protective net 113 is located above or outside the cooling fan 220. In some embodiments, the protective net 113 can be detachably installed at the bottom of the battery pack 100 by means of affixing or snap-fitting. In some embodiments, a protective net or baffle is also provided below the cooling fan 220 of the electrical device 200.

[0152] In some embodiments, as shown in FIG8, the electrical device 200 further includes a vibration damping member 221, which may be disposed between the cooling fan 220 and the device body to mitigate the impact of fan vibration and noise on the electrical device 200. Exemplarily, the cooling fan 220 drives forced convection to dissipate heat from the battery pack 100, and may be disposed on the housing of the electrical device 200 through the housing. The vibration damping member 221 may at least be disposed around the cooling fan 220 and sandwiched between the device body and the cooling fan 220. In some embodiments, the vibration damping member 221 may be vibration-damping foam. In some embodiments, the cooling fan 220 is installed in the electrical device 200 in a manner that facilitates disassembly, and the fan 220 and the vibration damping member 221 sandwiched between it and the housing are easy to replace and maintain.

[0153] Understandably, the other specific embodiments described above can also be incorporated into this embodiment to comprehensively optimize the thermal management of the battery pack.

[0154] Following the preceding text, the electrical device 200 adapted to the power tool battery pack 100 is equipped with a cooling fan 220, which can perform air cooling on the battery pack 100 from the outside. The operation of this cooling fan 220 can significantly affect the heat dissipation effect of the battery pack 100. Insufficient air cooling results in a small temperature drop and poor heat dissipation of the battery pack 100, potentially still posing a risk of thermal runaway. Conversely, excessive air cooling leads to a large temperature difference within the battery pack 100, which can cause problems such as thermistor components like NTC (Negative Temperature Coefficient) sensors malfunctioning within a controllable range. Referring to Figures 14 and 15, in one alternative embodiment of this application, a control logic for the cooling fan 220 within the power tool 201 is proposed. The power tool 201 includes a housing assembly 110 with an internal space for accommodating other components, a battery mounting section 210 with a tool terminal 211 that can be electrically coupled to the battery terminal 125 of the battery pack 100, and a cooling fan 220 fixed to the power tool 201 near the battery pack 100 to generate convection and dissipate heat from the battery pack 100. It also includes a temperature sensor 232 and a controller 231. The temperature sensor 232 is configured to detect the battery temperature of the battery pack 100 and / or the ambient temperature, while the controller 231 is configured to dynamically control the operating mode of the cooling fan 220 based on the current battery temperature and ambient temperature. In this embodiment, the cooling fan 220 that performs air cooling for the battery pack 100 within the power tool 201 does not operate at a constant speed; its start / stop and speed are adaptively and dynamically adjusted according to real-time changes in the battery temperature inside the battery pack 100 and the ambient temperature surrounding the battery pack 100. Specifically, the temperature sensor 232 of the power tool 201 can detect and / or acquire the aforementioned battery temperature and ambient temperature. In some embodiments, the temperature sensor 232 includes an ambient temperature sensor disposed on the power tool 201, which can detect the aforementioned ambient temperature. Exemplarily, this ambient temperature sensor can be disposed near the battery mounting portion 210, for example, it can be disposed within the battery compartment 210a. In some embodiments, the temperature sensor 232 detects and / or acquires the aforementioned battery temperature. For example, the temperature measured by the temperature sensor 232 disposed on the tool terminal 211 can be considered as the battery temperature; or, the power tool 201 can interact with the battery temperature sensor 232 disposed inside the battery pack 100 to obtain the battery temperature inside the battery pack 100. In some embodiments, the aforementioned battery temperature can include the temperature of any one or more battery cells 121 within the battery pack 100 housing or its calculated value (maximum value, average value, etc.), the temperature of the circuit board within the battery pack 100 housing, and the temperature of components such as MOSFETs within the battery pack 100 housing.

[0155] In some embodiments, during the operation of the power tool 201, its controller 231 controls the operating mode of the cooling fan 220 within the power tool 201 based on the numerical relationship between the current battery temperature and a battery temperature threshold, and the numerical relationship between the current ambient temperature and an ambient temperature threshold. The battery temperature threshold and the ambient temperature threshold can be preset based on one or more of the following: battery characteristics, the heat dissipation requirements of the battery pack 100, and the operating conditions of the battery pack 100 and / or the power tool 201. Understandably, these thresholds are positively correlated with the output power of the battery pack 100 and / or the heat dissipation requirements of the power tool 201. Furthermore, in this embodiment, at least one of the battery temperature threshold and the ambient temperature threshold has at least two threshold levels, resulting in at least six possible scenarios considering both the numerical relationships between the battery temperature and its threshold, and the numerical relationships between the ambient temperature and its threshold. By distinguishing between different scenarios and implementing different strategies, the power tool 201 can flexibly control the cooling fan 220 to operate in different modes to provide efficient and accurate air cooling for the battery pack 100.

[0156] In some embodiments, as shown in FIG15 and Table 1, the controller 231 of the power tool 201 is configured to control the cooling fan 220 to operate in low-speed mode when the current battery temperature is lower than a first battery temperature threshold and the current ambient temperature is greater than or equal to a first ambient temperature threshold. Correspondingly, in some embodiments, the controller 231 is configured to control the cooling fan 220 not to operate when the current battery temperature is lower than the first battery temperature threshold and the current ambient temperature is lower than the first ambient temperature threshold.

[0157] In other embodiments, as shown in FIG15 and Table 1, the controller 231 of the power tool 201 is configured to control the cooling fan 220 to operate in medium speed mode when the current battery temperature is greater than or equal to a first battery temperature threshold, less than a second battery temperature threshold, and the current ambient temperature is greater than or equal to a first ambient temperature threshold. Correspondingly, in some embodiments, the controller 231 is configured to control the cooling fan 220 to operate in low speed mode when the current battery temperature is greater than or equal to a first battery temperature threshold, less than a second battery temperature threshold, and the current ambient temperature is less than a first ambient temperature threshold.

[0158] In some embodiments, as shown in FIG15 and Table 1, the controller 231 of the power tool 201 is configured to control the cooling fan 220 to operate in high-speed mode when the current battery temperature is greater than or equal to a second battery temperature threshold and the current ambient temperature is greater than or equal to a first ambient temperature threshold. Correspondingly, in some embodiments, the controller 231 is configured to control the cooling fan 220 to operate in medium-speed mode when the current battery temperature is greater than or equal to the second battery temperature threshold and the current ambient temperature is less than the first ambient temperature threshold.

[0159] Understandably, in the above embodiments, the first battery temperature threshold is lower than the second battery temperature threshold. When the cooling fan 220 is not operating, its speed is zero and there is no airflow. The speed of the cooling fan 220 in low-speed mode is lower than its speed in medium-speed mode, and the airflow and heat dissipation intensity in low-speed mode are weaker than those in medium-speed mode. The speed of the cooling fan 220 in medium-speed mode is lower than its speed in high-speed mode, and the airflow and heat dissipation intensity in medium-speed mode are weaker than those in medium-speed mode.

[0160]

[0161] Table 1

[0162] Correspondingly, this application also proposes a control method for a power tool 201, which, as described above, may include a battery mounting section 210, a cooling fan 220, a temperature sensor 232, and a controller 231. The controller 231 executes this control method based on temperature data from the temperature sensor 232 to control the operation of the cooling fan 220. This control method includes controlling the operating mode of the cooling fan 220 based on the numerical relationship between the current battery temperature of the battery pack 100 and a battery temperature threshold, and the numerical relationship between the current ambient temperature and an ambient temperature threshold. It is understood that the content of the various specific embodiments related to the control logic of the cooling fan 220 of the power tool 201 described above can be adaptively combined with this embodiment to achieve the above optimizations.

[0163] In some embodiments, the control method for the power tool 201 described above may include some or all of the following specific steps:

[0164] Step 02: Determine whether the current battery temperature of the battery pack 100 is greater than or equal to the first battery temperature threshold.

[0165] Step 04: If not, determine whether the current ambient temperature of the battery pack 100 is greater than or equal to the first ambient temperature threshold. If yes, control the cooling fan 220 to work in low speed mode; otherwise, control the cooling fan 220 to not work.

[0166] Step 06, if yes, further determine whether the current battery temperature of the battery pack 100 is greater than or equal to the second battery temperature threshold.

[0167] Step 08: If not, determine whether the current ambient temperature of the battery pack 100 is greater than or equal to the first ambient temperature threshold. If yes, control the cooling fan 220 to work in medium speed mode; otherwise, control the cooling fan 220 to work in low speed mode.

[0168] Step 10: If yes, determine whether the current ambient temperature of the battery pack 100 is greater than or equal to the first ambient temperature threshold. If yes, control the cooling fan 220 to work in high speed mode; otherwise, control the cooling fan 220 to work in medium speed mode.

[0169] Following the foregoing, in another alternative embodiment of this application, an electrical device 200 is proposed to enable the cooling fan 220 to efficiently and accurately cool the battery pack 100 from the outside. This electrical device 200 includes, in addition to a housing assembly 110 forming an internal space to accommodate other components, a battery mounting portion 210 having device terminals 211 that can be electrically coupled to the battery terminals 125 of the battery pack 100, and a cooling fan 220 fixed to the electrical device 200 near the battery pack 100 to generate convection for heat dissipation from the battery pack 100, a temperature sensor 232 and a controller 231. The temperature sensor 232 is configured to detect the battery temperature and / or ambient temperature of the battery pack 100, and the controller 231 is configured to control the operating mode of the cooling fan 220 based on the numerical relationship between the current battery temperature and a battery temperature threshold, and the numerical relationship between the current ambient temperature and an ambient temperature threshold. It is understood that the content of the various specific embodiments related to the control logic of the cooling fan 220 of the power tool 201 described above can be adaptively combined with this embodiment to achieve the above optimization. It should also be noted that in the aforementioned control logic for the cooling fan 220 of electrical equipment 200, both electrical equipment 200 and battery pack 100 are considered independent entities. Battery pack 100 can be detached from electrical equipment 200 to exchange power with different power tools 201 and / or chargers 202 and / or adapters. Cooling fan 220 is a component subordinate to and located within electrical equipment 200. When battery pack 100 is connected to electrical equipment 200, the cooling fan 220 of electrical equipment 200 dissipates heat from the battery pack 100. This is distinctly different from the built-in fan in electric vehicles that cools the internal battery; the specific design and emphasis of this difference are clear to technicians.

[0170] In some embodiments, the aforementioned electrical equipment 200 includes power tools 201 such as ride-on lawnmowers, self-propelled lawnmowers, all-terrain vehicles, circular saws, chainsaws, reciprocating saws, nail guns, screwdrivers, etc., and also includes chargers 202, adapters, etc. In some embodiments, the controller 231 of the power tool 201 is configured to control the cooling fan 220 to stop when any of the following occurs: the power tool 201 (main unit) stops, exemplarily including situations such as the power tool 201 completing its current task; the current battery temperature of the battery pack 100 is below a shutdown battery temperature threshold, which is less than the aforementioned first battery temperature threshold, indicating that the battery pack 100 does not require air cooling. In some embodiments, the controller 231 of the charger 202 or adapter is configured to control the cooling fan 220 to stop when any of the following occurs: the charger 202 or adapter (main unit) stops; the battery pack 100 completes charging, for example, the current battery level of the battery pack 100 reaches full charge; the current battery temperature of the battery pack 100 is below the shutdown battery temperature threshold.

[0171] In some embodiments, in addition to the three-speed mode of the cooling fan 220 described above, the power tool 201, charger 202, and other electrical devices 200 control the cooling fan 220 to have more different operating modes, including but not limited to long-life mode and low-noise mode. Specifically, in the aforementioned long-life mode, the controller 231 of the electrical device 200 can continuously monitor one or more parameters of the battery pack 100, such as battery temperature, discharge rate, and SOC (State of Charge). Based on the current battery temperature and ambient temperature of the battery pack 100, and combined with at least one of the parameters such as the battery temperature rise rate, SOC change rate, and discharge rate in the previous period, the controller 231 continuously and intelligently adjusts the speed of the cooling fan 220 to keep the ambient temperature around the battery pack 100 in a dynamic equilibrium within an ideal temperature range, such as 10°C to 35°C; and / or, continuously and intelligently adjusts the speed of the cooling fan 220 to keep the battery temperature inside the battery pack 100 in a dynamic equilibrium within an ideal temperature range. In the aforementioned low-noise mode, the controller 231 of the electrical device 200 will control the cooling fan 220 to operate at a relatively slow speed to reduce the noise emitted. In this mode, it is not necessary to consider whether the current battery temperature exceeds the threshold.

[0172] In one alternative embodiment of this application, referring to Figures 10 to 13B, the battery pack 100 includes a housing assembly 110 and a battery module 120 disposed within the housing assembly 110. The battery module 120 includes a plurality of battery cells 121 and has two polar end faces 1201 perpendicular to the longitudinal extension direction of the battery cells 121. To improve thermal management of the battery pack, the battery pack 100 further includes an exhaust assembly 140, which is disposed within the housing assembly 110 and has an exhaust channel 141 for guiding and discharging gas. Simultaneously, one of the two polar end faces 1201 of the battery module 120 within the battery pack 100 is a heat dissipation surface 1201b, and the other is an exhaust surface 1201a. The heat dissipation surface 1201b is at least partially covered with a thermally conductive material 122 or thermally conductive adhesive 122 that can conduct heat generated by the battery module 120 to an external heat dissipation structure. The exhaust ports 1211 of each battery cell 121 arranged on the exhaust surface 1201a are directed toward the air inlet 1411 of the exhaust channel 141 of the exhaust assembly 140, which can guide the gas generated by the battery cell 121 to be discharged. Therefore, it can take into account both battery heat dissipation and pressure relief, and deal with battery thermal runaway from both prevention and response perspectives.

[0173] Specifically, multiple battery cells 121 within the battery module 120 are arranged in a generally parallel manner. Taking a cylindrical cell as an example, the electrodes at both ends of the axial direction of the multiple battery cells 121 are approximately located on the same plane, thus forming the two polar end faces 1201 perpendicular to the longitudinal extension direction of the battery cells 121. As shown in Figures 13A and 13B, in this embodiment, one of the faces is provided as a heat dissipation surface 1201b. A thermally conductive material 122 or a thermally conductive adhesive 122 is coated / attached to the polar end face 1201 serving as the heat dissipation surface 1201b, and at least a portion of the heat dissipation surface 1201b is covered by the thermally conductive material 122 or the thermally conductive adhesive 122. For example, at least the portion where the cell electrodes are located is covered by the thermally conductive material 122 or the thermally conductive adhesive 122, and the heat generated by each battery cell 121 is efficiently and quickly conducted outward through the thermally conductive material 122 or the thermally conductive adhesive 122 on the polar end face 1201. Regarding the specific implementation of covering the heat dissipation surface 1201b with thermally conductive material 122 or thermally conductive adhesive 122, reference can be made to the relevant content in the various embodiments of heat dissipation plates or metal plates with thermally conductive material / thermally conductive adhesive described above, or a combination thereof. Exemplarily, the external heat dissipation structure outside the heat dissipation surface 1201b that receives the heat conducted by the thermally conductive material 122 can be the battery pack 100 housing and the external space (external environment), or it can be the thermally conductive plastic part 123 sandwiched between the thermally conductive material 122 and the battery pack 100 housing, the battery pack 100 housing, and the external space. In some embodiments, the battery pack 100 housing, which is in direct or indirect thermal contact with the thermally conductive material 122, is made of metal plate 111. Furthermore, the content in the various embodiments described above, where the outer wall of the battery pack housing (heat dissipation housing / heat dissipation plate / metal plate) is provided with heat dissipation channels to guide forced convection or natural convection for heat dissipation of the battery pack, can also be incorporated.

[0174] In this embodiment, another side is also provided as an exhaust surface 1201a. The depressurized gas from the battery cells 121 is guided and discharged through this polar end face 1201, which serves as the exhaust surface 1201a. The air inlet 1411 of the exhaust channel 141 in the exhaust assembly 140 is positioned facing the exhaust outlet 1211 of each battery cell 121 on the exhaust surface 1201a. The air outlet 1412 of the exhaust channel 141 communicates with the external space of the pack. The gas generated by the battery cells 121 can then smoothly enter the exhaust channel 141 from the air inlet 1411 and be discharged outside the pack through the air outlet 1412. In some embodiments, the plane of the exhaust assembly 140 is substantially parallel to the exhaust surface 1201a, and the extending direction of the exhaust channel 141 intersects with or is substantially perpendicular to the exhaust surface 1201a. In some embodiments, the orthographic projections of the polar end faces 1201 of different battery modules 120 within the battery pack 100 along the longitudinal extension direction of the battery cell 121 do not overlap. The venting assembly 140 may be located between the venting surface 1201a of the battery module 120 and the outer casing of the battery pack 100. The outlet 1412 of the venting channel 141 faces directly toward the outer casing of the battery pack 100 and vents outside the pack through an opening thereon or by breaking through the casing during depressurization. Exemplarily, the airflow path for the gas generated by the battery cell 121 to vent outside the pack may be straight. In some embodiments, the polar end faces 1201 of the different battery modules 120 within the battery pack 100 overlap in their orthographic projection along the longitudinal extension direction of the battery cell 121. For example, two battery modules 120 may be arranged face-to-face within the battery pack 100 housing with their venting surfaces 1201a facing each other. The exhaust assembly 140 can be located between the exhaust surfaces 1201a of the two battery modules 120. After the gas generated by the battery cell 121 leaves the exhaust assembly 140, it may also pass through other airflow channels formed between the exhaust assemblies 140, between the exhaust assembly 140 and the outer shell of the battery pack 100, or between the exhaust assembly 140 and other inner shells of the battery pack 100, and finally leave the battery pack 100 to reach the external environment. The airflow path can be straight or zigzag. In some embodiments, the exhaust assembly 140 includes a first exhaust assembly, a second exhaust assembly, etc., corresponding to different battery modules 120. For example, a partition 142 or the like can be provided between the exhaust assemblies 120 corresponding to different battery modules 120 to avoid the influence of the depressurized gas of one side on the other. In other embodiments, two or more battery modules 120 may also share the same exhaust assembly 140, but their respective exhaust channels 141 may not be shared to avoid mutual interference of the depressurized gas. In some embodiments, the exhaust assembly 140 is generally flat, with multiple exhaust channels 141 perpendicular to the surface of the plate passing through the inside of the plate, and the air inlet 1411 on the plate is opposite to the exhaust port 1211 of the battery unit 121.In other embodiments, the specific implementation of the exhaust assembly 140 described above may also refer to or in part to the descriptions in Chinese patents filed by the applicant with application numbers 202410114969.5 and 202310494442.5.

[0175] In some embodiments, as shown in FIG12, the battery pack 100 further includes a cell connecting piece 124 for electrically connecting multiple battery cells 121 on a polarized end face 1201. The cell connecting piece 124 on the venting surface 1201a may have a fuse 1241. Specifically, taking a generally parallel arrangement of cylindrical cells as an example, the electrodes at both ends of the cells are respectively arranged on the two polarized end faces 1201. The cell connecting piece 124 can connect different cell electrodes on the polarized end face 1201 to complete the series and parallel connection between cells within the battery module 120 of the battery pack 100. Since the venting surface 1201a performs a venting function, the discharge of depressurized gas may interfere with the electrical connection between other cells. Therefore, a fuse 1241 is also installed on the cell connecting piece 124 on the venting surface 1201a to ensure related safety. In some embodiments, a heat-insulating sticker may be affixed to the cell connection piece 124 on the exhaust surface 1201a to mitigate the interference of the high-temperature and high-pressure gas discharged from the failed cell on other cells, thereby ensuring relevant safety.

[0176] In some embodiments, both ends of the battery cell 121 can perform pressure relief and venting in the event of thermal runaway. When implementing the above-mentioned scheme of heat dissipation on one end and venting on the other, the battery module 120 composed of series-parallel connected cells does not require specific orientation of the cell electrodes when multiple cells are connected in series and parallel. The end of the cell located on the heat dissipation surface 1201b, due to the covering of the thermally conductive material 122, experiences greater resistance in pressure relief compared to the other end located on the venting surface 1201a, thus allowing the gas generated by the battery cell 121 to escape from the venting surface 1201a. In some embodiments, the polar end face 1201 where more cells have positive electrodes is designated as the heat dissipation surface 1201b, and the other polar end face 1201 where more cells have negative electrodes is designated as the venting surface 1201a.

[0177] In some embodiments, the positive and negative electrodes of the battery cells 121 within the same battery module 120 can be arranged in the same orientation, with multiple positive electrodes located on one plane and multiple negative electrodes located on opposite planes. Exemplarily, the multiple battery cells 121 within the battery module 120 can be connected in parallel. In some embodiments, the heat dissipation surface 1201b is the positive end face of the battery where the positive electrode of the cell is located, and the venting surface 1201a is the negative end face of the battery where the negative electrode of the cell is located. This allows for rapid and efficient heat conduction using the end face where the positive electrode of the cell is located, and for venting and depressurization using the end face where the negative electrode of the cell is located, thus preventing short circuits in parallel cells.

[0178] In some embodiments, only one end of the battery cell 121 can perform pressure relief and venting in the event of thermal runaway. When implementing the above-mentioned scheme of heat dissipation on one end and venting on the other end in the form of a battery module 120 composed of multiple cells connected in series and parallel, there are certain requirements on the orientation of the cell electrodes when multiple cells are connected in series and parallel. For example, as shown in Figures 11A and 11B, multiple battery cells 121 can be connected in parallel to form a battery module 120, and multiple battery modules 120 can be connected in series to form a battery pack 100. The battery cells 121 are connected in parallel on the polar end face 1201 where the cell electrodes are located (such as the front and back sides) using cell connecting pieces 124. The battery modules 120 are connected in series on other side end faces 1201 where the non-cell electrodes are located (such as the left and right sides) using module connecting pieces 126 such as series copper busbars, so that the electrodes of all cells in the battery pack 100 have the same orientation and are arranged on the two polar end faces 1201. In some embodiments, the battery cell 121 performs pressure relief and venting with its positive terminal. The positive terminal face of the battery, formed by the positive electrode of the cell, is designated as the venting surface 1201a, and the negative terminal face of the battery, formed by the negative electrode of the cell, is designated as the heat dissipation surface 1201b. In other embodiments, the battery cell 121 performs pressure relief and venting with its negative terminal. The negative terminal face of the battery, formed by the negative electrode of the cell, is designated as the venting surface 1201a, and the positive terminal face of the battery, formed by the positive electrode of the cell, is designated as the heat dissipation surface 1201b. When the battery pack 100 uses this type of single-end negative terminal venting cell to implement this solution, it can avoid short circuits between parallel cells and short circuits between the positive and negative electrodes of the cells, thus providing higher safety.

[0179] Considering the structure and electrical characteristics of the battery cell 121, the pressure relief and venting of the battery cell 121 on the venting surface 1201a may lead to short circuits between cells and short circuits between the positive and negative electrodes of the cell itself. The following provides an analysis and optimization for this problem. First, the structure of the battery cell 121 is introduced. Referring to Figures 9A to 9C, taking a cylindrical cell as an example, the battery cell 121 has a cylindrical metal casing 1211. The top of the metal casing 1211 is open, and a cylindrical receiving groove can be formed inside. The battery body 1212 of the battery cell 121 is housed within this receiving groove of the metal casing 1211. The top cover 1213 is sealed and installed on the open top of the battery cell casing 1211 to form a complete cell. The battery body 1212 includes a first electrode, a second electrode, and a separator located between the first and second electrodes. In the cylindrical battery cell, the first and second electrodes and the separator are wound and housed within a cylindrical casing 1211. The first electrode is electrically connected to the metal casing 1211 to bring out one electrode of the battery cell, and the second electrode is electrically connected to the top cover 1213 to bring out the other electrode of the battery cell. One of the first and second electrodes is the positive electrode of the battery cell, and the other is the negative electrode. One of the metal casing 1211 and the top cover 1213 connected to the positive electrode serves as the positive electrode of the battery cell, and the other of the metal casing 1211 and the top cover 1213 connected to the negative electrode serves as the negative electrode of the battery cell.

[0180] The first polar end face 1201 of the battery module 120, which is formed by arranging the bottom of the outer shell 1211 of the battery cell 121 connected to the first electrode, is designated as the first polar end face 1201a, and the other polar end face 1201 of the battery module 120, which is formed by arranging the top cover 1213 of the battery cell 121 connected to the second electrode, is designated as the second polar end face 1201b.

[0181] Currently, a common approach in related technologies is to connect the positive electrode of the battery cell to the top cover 1213 to serve as the positive electrode for welding the battery cell connecting piece 124, and to install an explosion-proof valve at the top cover 1213. The negative electrode of the battery cell is connected to the surrounding metal casing 1211, with the bottom end face of the casing serving as the negative electrode for welding the battery cell connecting piece 124. However, since the top cover 1213, which covers the open top of the battery cell's metal casing 1211, maintains electrical isolation between the casing 1211 and the top cover 1213 through a separate insulating component, the high-temperature, high-pressure gas acting on the explosion-proof valve of the top cover 1213 when the battery cell fails and releases pressure can easily damage the relevant structures, leading to a short circuit between the positive and negative electrodes of the battery cell and exacerbating safety issues. Therefore, this application proposes, in one implementation, to set the aforementioned first polarity end face 1201a as an exhaust surface 1201a, so that the gas generated by the battery cell 121 within the battery module 120 will be discharged from this end face 1201a connected to the casing 1211. The aforementioned second polarity end face 1201b is configured as a heat dissipation surface 1201b. The heat generated by the battery cells 121 within the battery module 120 is conducted by thermally conductive adhesive 122, which at least partially covers the other side of the end face 1201b connected to the top cover 1213. Specifically, multiple cylindrical battery cells within the battery module 120 are arranged in approximately parallel lines, and the top covers 1213 of the multiple battery cells within the module are approximately located on the same plane and arranged to form the aforementioned second polarity end face 1201b / heat dissipation surface 1201b. Thermally conductive materials 122, such as thermally conductive adhesive 122, are coated or adhered to at least a portion of the heat dissipation surface 1201b, thereby sealing at least the battery cell electrodes located on this second polarity end face 1201b and characterized by the battery cell top cover 1213. The heat generated by the battery cell is rapidly conducted by the thermally conductive material 122 on the top cover 1213, including but not limited to heat conduction to the housing 110 and the outside air, or heat conduction to the thermally conductive plastic part 123, the housing 110 and the outside air, etc., and heat exchange between the outside of the housing 110 and the outside air can also be achieved through the heat dissipation channel 111a provided on the outer wall of the housing 111. In some embodiments, the explosion-proof valve may not be provided at the top cover 1213 for the battery cell electrodes. The bottom end faces of the housings 1211 of multiple battery cells in the module are also roughly located on the same plane and arranged to form the first polarity end face 1201a / exhaust surface 1201a. The air inlet 1411 of the exhaust channel 141 that guides the depressurized gas can be provided facing the exhaust surface 1201a. Due to the thermally conductive material 122 on the heat dissipation surface 1201b sealing and fixing the top cover 1213 and its electrodes. Furthermore, the top cover 1213 may not be equipped with an explosion-proof valve, allowing the gas released from the cell failure to naturally escape from the bottom of the metal casing 1211 or other parts. For example, the thickness of the casing at the bottom of the cell can be relatively reduced, allowing the gas to enter the exhaust channel 141 of the exhaust assembly 140 from the exhaust surface 1201a and then be discharged.The gas venting from the metal casing 1211 allows the electrical connection of the battery cell to be quickly cut off, preventing short circuits between the cells or between the positive and negative electrodes. This effectively avoids interference to other cells after thermal runaway of a single cell. Compared with the related technologies described above, the safety of the battery pack 100 is significantly improved.

[0182] In some embodiments, the first electrode in the battery body 1212 of the battery cell 121 is a positive electrode, and the second electrode is a negative electrode. The first polarity end face / venting surface 1201a is the positive terminal face of the battery, and the second polarity end face / heat dissipation surface 1201b is the negative terminal face of the battery. In other embodiments, the first electrode in the battery body 1212 of the battery cell 121 is a negative electrode, and the second electrode is a positive electrode. The first polarity end face / venting surface 1201a is the negative terminal face of the battery, and the second polarity end face / heat dissipation surface 1201b is the positive terminal face of the battery. Essentially, the deployment of the heat dissipation surface 1201b and the venting surface 1201a of the battery module 120 is linked to the internal structure of the battery cell 121, but decoupled from the positive and negative electrodes of the battery cell.

[0183] As can be seen, this implementation deeply considers the problem of cell short circuits within the battery pack during thermal runaway, improves the design from the perspective of cell microstructure, addresses and solves the root causes of problems in related technologies, and effectively reduces the safety risks of the battery pack (for power tools). Furthermore, the other specific embodiments described above can also be incorporated into this implementation for comprehensive optimization of battery pack thermal management.

[0184] The technical effects of this application include at least: improving the heat dissipation and temperature uniformity of power tool battery packs, improving the explosion-proof and pressure relief effects, optimizing the prevention and response to thermal runaway of power tool battery packs, and enhancing the safety of power tool battery packs and their related systems (power tools, chargers, electrical equipment).

[0185] It is understood that the different specific embodiments or different specific implementations described above may be combined with each other to comprehensively optimize the power tool battery pack and electrical equipment in this application, provided that the features do not conflict, and this will not exceed the protection scope of this application.

[0186] The foregoing has shown and described the basic principles, main features, and advantages of this application. Those skilled in the art should understand that the above embodiments do not limit this application in any way, and all technical solutions obtained by equivalent substitution or equivalent transformation fall within the protection scope of this application.

Claims

1. A battery pack for power tools, comprising: The housing assembly forms a sealed cavity; The battery module is housed within the sealed cavity; The outer surface of the housing assembly on at least one side is provided with a heat dissipation channel, which guides forced convection flow through the outer surface of the battery pack housing to dissipate heat from the battery pack.

2. The battery pack according to claim 1, wherein, The housing assembly has a heat dissipation guide portion formed on the outer surface of at least one side of the housing, and the battery pack also includes a cover plate disposed on the outside of the heat dissipation housing having the heat dissipation guide portion, the cover plate cooperating with the heat dissipation guide portion to form the heat dissipation channel.

3. The battery pack according to claim 2, wherein, The cover plate is detachably installed on the outside of the heat dissipation housing.

4. The battery pack according to claim 1, wherein, The housing assembly has a heat dissipation guide formed on at least one side of its outer surface, and the power tool has a receiving compartment for accommodating the battery pack, the inner wall of which cooperates with the heat dissipation guide to form the heat dissipation channel.

5. The battery pack according to claim 1, wherein, The housing assembly includes a heat dissipation housing having the heat dissipation guide portion, wherein the heat dissipation guide portion is a heat dissipation fin formed on the heat dissipation housing.

6. The battery pack according to claim 1, wherein, The housing assembly includes a heat dissipation housing with heat dissipation channels on its outer surface, and the heat dissipation housing includes a metal plate and / or a heat dissipation plastic part.

7. The battery pack according to claim 6, wherein, The battery module has two polarized end faces perpendicular to the extension direction of the battery cells within the module, and the polarized end faces are disposed opposite to the heat dissipation housing.

8. The battery pack according to claim 7, wherein, The battery pack also includes thermally conductive adhesive that covers at least a portion of the polar end face and is in thermal contact with the heat dissipation housing. The thermally conductive adhesive conducts the heat generated by the battery cell to the heat dissipation housing, and then conducts it to the external environment through the heat dissipation housing.

9. The battery pack according to claim 1, wherein, The battery module includes multiple battery units; each battery unit includes: a housing, configured as a cylindrical metal shell, having at least an open top; a battery body, disposed within the housing, including a first electrode, a second electrode, and a separator located between the first electrode and the second electrode, the first electrode being electrically connected to the housing; and a top cover, sealed and installed at the top of the housing, and electrically connected to the second electrode.

10. The battery pack according to claim 9, wherein, The bottom of the outer casings of the plurality of battery cells are arranged to form the first polarity end face of the battery module, and the top cover of the plurality of battery cells is arranged to form the second polarity end face of the battery module; the first polarity end face is configured as an exhaust surface, and the gas generated by the battery cells in the battery module is discharged from the exhaust surface; the second polarity end face is configured as a heat dissipation surface, and at least a portion of the second polarity end face is covered with a thermally conductive material that conducts heat generated by the battery module.

11. The battery pack according to claim 10, wherein, The first electrode is set as a positive electrode and the second electrode is set as a negative electrode; or, the first electrode is set as a negative electrode and the second electrode is set as a positive electrode.

12. The battery pack according to claim 1, wherein, The housing assembly includes a heat dissipation housing with heat dissipation channels on its outer surface, and the thermal conductivity of the heat dissipation housing is greater than 0.3 W / (m·K).

13. The battery pack according to claim 1, wherein, The heat dissipation channel guides forced convection to flow from top to bottom across the outer surface of the battery pack to dissipate heat from the battery pack.

14. The battery pack according to claim 1, wherein, Power tools or chargers are equipped with cooling fans that generate forced convection.

15. The battery pack according to claim 14, wherein, The battery pack also includes a protective net disposed at the bottom of the battery pack; when the battery pack is installed on the power tool, the protective net is located approximately above the cooling fan.

16. A battery pack for power tools, comprising: The housing assembly forms a sealed cavity; The battery module is housed within the sealed cavity; The outer surface of at least one side of the housing assembly has a heat dissipation guide portion; The power tool has a housing compartment for accommodating the battery pack, wherein the heat dissipation guide cooperates with the inner wall of the housing compartment to form a heat dissipation channel to guide forced convection flow through the heat dissipation channel and dissipate heat from the battery pack; and / or, the battery pack further includes a cover plate disposed outside the heat dissipation housing having the heat dissipation guide, and cooperating with the heat dissipation guide to form a heat dissipation channel to guide forced convection flow through the heat dissipation channel and dissipate heat from the battery pack.

17. The battery pack according to claim 16, wherein, The housing assembly includes a heat dissipation housing with heat dissipation channels on its outer surface; the battery module includes multiple battery cells and has two polar end faces perpendicular to the longitudinal extension direction of the battery cells; the battery pack also includes: thermally conductive adhesive, which covers at least part of the polar end faces and is in thermal contact with the heat dissipation housing; the thermally conductive adhesive is configured to conduct the heat generated by the battery cells to the heat dissipation housing and conduct it out to the external environment through the heat dissipation housing.

18. The battery pack according to claim 17, wherein, The heat dissipation housing is a metal plate; the battery pack also includes a thermally conductive plastic component, which is disposed between the metal plate and the thermally conductive adhesive.

19. An electrical device comprising: The battery mounting section has a device terminal, which is configured to be electrically connected to the battery terminal of the battery pack to perform power transmission between the battery pack and the electrical device; The battery pack includes: a housing assembly having a sealed cavity for accommodating the battery module, and a heat dissipation channel is provided on at least one side of the outer surface of the housing assembly; The electrical equipment further includes a cooling fan, which is fixed to the electrical equipment and disposed near the battery pack, and configured to generate forced convection flowing through the heat dissipation channel.

20. The electrical equipment according to claim 19, wherein, The electrical equipment includes a charger or a power tool, the power tool including one or more of a push-type working machine, a ride-on working machine, and a self-propelled working machine; the cooling fan is located at the bottom of the battery mounting section.

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