Battery pack

Abstract

The invention discloses a battery pack. The battery pack comprises a shell; the electric tool interface is arranged to be connected with the electric tool; the battery cell module is accommodated in the shell, and the battery cell module comprises a plurality of battery cell units; the battery cell connecting sheet is arranged to be connected with at least two battery cell units; wherein under the condition that the battery pack continuously supplies power to the electric tool at the current of 100A for at least 30 seconds, the temperature rise of the battery core connecting piece is less than or equal to 120 DEG C.

Description

Technical Field

[0001] The present application relates to the technical field of electric tools, and in particular to a battery pack. Background Art

[0002] With the development of battery technology, power tools are gradually replacing engine tools. In order to make cordless power tools have better use effects, the battery pack is also required to have higher output characteristics. For example, garden tools require battery packs to have longer battery life, handheld power tools require battery packs to have higher energy density, and various types of power tools require battery packs to have higher continuous discharge power, or higher charging rates, etc. This also means that the structural characteristics of the battery pack itself require it to withstand a larger operating current. This section provides background information related to this application, which is not necessarily prior art. Summary of the invention

[0003] One object of the present application is to solve or at least alleviate part or all of the above problems. To this end, one object of the present application is to provide a battery pack with better performance.

[0004] In order to achieve the above objectives, this application adopts the following technical solutions:

[0005] A battery pack for powering an electric tool, comprising: a shell; an electric tool interface, configured to be connected to the electric tool; a battery cell module, accommodated in the shell, the battery cell module comprising a plurality of battery cell units; a battery cell connecting piece, configured to connect at least two of the battery cell units; wherein, when the battery pack continuously powers the electric tool at a current of 100 A for at least 30 seconds, the temperature rise of the battery cell connecting piece is less than or equal to 120°C.

[0006] In one embodiment, a reinforcing piece is provided on the non-welding surface of the battery cell connecting piece.

[0007] In one embodiment, the reinforcement comprises a metal sheet or a metal coating.

[0008] In one embodiment, the reinforcement member comprises a copper sheet or a copper coating.

[0009] In one embodiment, the thickness of the reinforcing piece is greater than or equal to 0.1 mm and less than or equal to 2 mm.

[0010] In one embodiment, the thickness of the reinforcing piece is greater than or equal to 0.2 mm and less than or equal to 1 mm.

[0011] In one embodiment, the number of welding points between the battery cell connecting sheet and the battery cell unit is greater than or equal to 4 and less than or equal to 8.

[0012] In one embodiment, a surface shape of the reinforcing member is different from a surface shape of the battery cell connecting piece.

[0013] In one embodiment, the surface shape of the reinforcing member is consistent with the surface shape of the battery cell connecting piece.

[0014] In one embodiment, the reinforcing member is disposed on the battery cell connecting sheet in a manner including at least one of welding, rolling or composite processes.

[0015] In one embodiment, the reinforcing member is made of a material different from the battery cell connecting sheet.

[0016] A battery pack comprises: a shell; a battery cell module contained in the shell, wherein the battery cell module comprises a plurality of battery cell units; and a battery cell connecting piece configured to connect at least two of the battery cell units; wherein the contact impedance between the battery cell connecting piece and the battery cell units is less than or equal to 10 μΩ.

[0017] In one embodiment, a reinforcing piece is provided on the non-welding surface of the battery cell connecting piece.

[0018] A battery pack for powering an electric tool, comprising: a shell; an electric tool interface for connecting to the electric tool, the electric tool interface comprising a terminal assembly; a battery cell module accommodated in the shell and electrically connected to the terminal assembly, the battery cell module comprising at least a plurality of battery cell units; wherein the continuous discharge power of the battery cell unit is greater than or equal to 300W.

[0019] In some embodiments, the instantaneous discharge power of the battery cell unit is greater than or equal to 550W.

[0020] In some embodiments, the power density of the battery pack is greater than or equal to 1500 W / kg.

[0021] In some embodiments, the battery cell unit is a full-tab battery.

[0022] In some embodiments, the terminal assembly includes a first positive terminal, a second positive terminal, a negative terminal, and a communication terminal.

[0023] In some embodiments, the battery pack is further configured to be detachably mounted to a riding vehicle to power the riding vehicle.

[0024] In some embodiments, the battery pack is further configured to be detachably mounted to a mobile power source to at least supply power to the mobile power source.

[0025] In some embodiments, the minimum distance between every two adjacent battery cell units in the plurality of battery cell units is greater than or equal to 2 mm.

[0026] A battery pack for powering an electric tool, comprising: a shell; an electric tool interface for connecting to the electric tool, the electric tool interface comprising a terminal assembly; a battery cell module accommodated in the shell and electrically connected to the terminal assembly, the battery cell module comprising at least one battery cell unit; wherein the maximum discharge rate of the battery pack is greater than or equal to 20C and less than or equal to 50C.

[0027] In some embodiments, at least one of the battery cells is a full-tab battery.

[0028] In some embodiments, the resistance of at least one of the battery cells is less than or equal to 10 mΩ.

[0029] In some embodiments, the energy density of at least one of the battery cells is greater than or equal to 600Wh / L.

[0030] In some embodiments, the charging rate of the battery pack is greater than or equal to 4C and less than or equal to 10C.

[0031] A battery pack comprises: a shell; an interface for connecting to an electrical device, the interface comprising a terminal assembly; a battery cell module accommodated in the shell and electrically connected to the terminal assembly, the battery cell module comprising a plurality of battery cell units; wherein, when the remaining power of the battery pack is greater than or equal to 50% and is discharged to the electrical device at a discharge rate greater than or equal to 2C at a preset temperature, the voltage drop of the battery cell unit is less than or equal to 100mV.

[0032] In some embodiments, the battery cell is a cylindrical battery.

[0033] In some embodiments, the battery cell unit is a full-tab battery.

[0034] In some embodiments, the power density of the battery pack is greater than or equal to 1500 W / kg.

[0035] In some embodiments, the preset temperature ranges from -20°C to 60°C.

[0036] A handheld electric tool comprises: a shell; a working piece; a motor, arranged in the shell and used to drive the working piece; a battery pack, detachably mounted to the shell and used to supply power to the motor; wherein the weight of the battery pack is less than or equal to 4kg, and the battery pack can continuously provide the motor with a power greater than or equal to 6kW.

[0037] In some embodiments, the battery pack includes a plurality of battery cells; at least one of the battery cells is a full-tab battery.

[0038] In some embodiments, the handheld power tool is a garden tool.

[0039] In some embodiments, the handheld power tool is a chain saw.

[0040] In some embodiments, the battery cell is a cylindrical battery.

[0041] In some embodiments, the resistance of at least one of the battery cells is less than or equal to 10 mΩ.

[0042] A battery pack comprises: a shell; an interface for detachably connecting to an electrical device or a charging device, the interface comprising a terminal assembly; a battery cell module accommodated in the shell and electrically connected to the terminal assembly, the battery cell module comprising a plurality of cylindrical battery cell units; wherein, when the interface is electrically connected to the charging device and the power level of the battery pack is less than or equal to a first threshold, the charging rate of the battery pack is greater than or equal to 4C and less than or equal to 10C.

[0043] In some embodiments, the powered device includes a riding lawn mower.

[0044] In some embodiments, the power-consuming device or the charging device includes a mobile power source.

[0045] In some embodiments, the continuous discharge power of the battery cell unit is greater than or equal to 300W.

[0046] In some embodiments, the power density of the battery pack is greater than or equal to 1500 W / kg.

[0047] In some embodiments, the first threshold is greater than or equal to 70% and less than or equal to 90%.

[0048] In some embodiments, the battery pack includes at least 10 battery cell units, and the battery cell units are full-tab batteries.

[0049] In some embodiments, the battery cell unit is a full-tab battery.

[0050] In some embodiments, the interface is configured to be connected to an adapter, and the adapter can be connected to AC power or DC power as a charging power source.

[0051] A battery pack comprises: a shell; a battery cell module accommodated in the shell, the battery cell module comprising a plurality of battery cell units, the plurality of battery cell units comprising at least one full-tab battery; wherein the battery pack further comprises: a first interface, at least for connecting to an electrical device, the first interface comprising a first terminal assembly; a second interface, at least for connecting to a charging device, the second interface comprising a second terminal assembly; at least some of the components of the first terminal assembly and the second terminal assembly are different.

[0052] In some embodiments, the battery cell is a cylindrical battery.

[0053] In some embodiments, the electrical device includes a garden tool or a handheld tool.

[0054] In some embodiments, the charging device includes a charger or an adapter.

[0055] In some embodiments, the resistance of at least one of the battery cells is less than or equal to 10 mΩ.

[0056] In some embodiments, the energy density of at least one of the battery cells is greater than or equal to 600Wh / L.

[0057] In some embodiments, the charging rate of the battery pack is greater than or equal to 3C and less than or equal to 10C.

[0058] In some embodiments, the first terminal assembly includes a first positive terminal, a negative terminal and a communication terminal; the second terminal assembly includes a second positive terminal, the negative terminal and the communication terminal.

[0059] A battery pack comprises: a shell; a terminal assembly, arranged in the shell; a plurality of battery cell units, arranged in the shell, each of the battery cell units comprising a positive pole lug and a negative pole lug; wherein the positive pole lug or the negative pole lug is a full-pole lug structure; the shell also comprises a heat dissipation structure, and the minimum distance between the positive pole lug or the negative pole lug and the heat dissipation structure in the axial direction of the battery cell unit is less than or equal to 1 cm.

[0060] In some embodiments, the heat dissipation structure includes a busbar.

[0061] In some embodiments, the heat dissipation structure includes at least one heat dissipation material selected from the group consisting of nickel strip, copper, and nickel-plated copper.

[0062] In some embodiments, the heat dissipation structure includes a heat dissipation channel; an inlet of the heat dissipation channel faces at least one end surface of the battery cell unit.

[0063] In some embodiments, the heat dissipation structure includes a hydrogel.

[0064] An electric tool comprises: a housing; a working piece; a motor, arranged in the housing and used to drive the working piece; an energy storage device, used to supply power to the motor, the energy storage device comprising a plurality of battery cells; wherein the energy storage device is configured to store feedback current, wherein the maximum feedback current of each of the battery cells is greater than or equal to 10 amperes.

[0065] In some embodiments, the battery cell unit is a full-tab battery.

[0066] In some embodiments, the internal resistance of the battery cell is less than or equal to 10 mΩ.

[0067] In some embodiments, the energy storage device is disposed inside the housing.

[0068] In some embodiments, the energy storage device is detachably mounted to the outside of the housing.

[0069] An electric tool comprises: a shell; a working piece; a motor, arranged in the shell, for driving the working piece; a battery pack interface, arranged in the shell, for detachably installing a battery pack, the battery pack interface transmitting electrical energy from the battery pack to power the motor; a drive circuit, for driving the motor to rotate; a controller, configured to control the drive circuit; characterized in that the controller is also configured to: when it is recognized that the battery pack interface is connected to a first battery pack, set the overcurrent protection threshold of the electric tool to a first threshold; when it is recognized that the battery pack interface is connected to a second battery pack, set the overcurrent protection threshold of the electric tool to a second threshold; wherein the first threshold is greater than or equal to twice the second threshold, and the volumes of the first battery pack and the second battery pack are the same within a preset volume floating range.

[0070] In some embodiments, the first battery pack includes a plurality of battery cell units, and the plurality of battery cell units are full-tab batteries.

[0071] In some embodiments, the controller is further configured to: when identifying that the battery pack interface is connected to a first battery pack, set the overcurrent protection response time to a first duration; when identifying that the battery pack interface is connected to a second battery pack, set the overcurrent protection response time to a second duration; wherein the first duration is greater than the second duration.

[0072] In some embodiments, the number of battery cell units in the first battery pack is substantially the same as the number of battery cell units in the second battery pack.

[0073] A battery pack comprises: a shell; a terminal assembly, arranged in the shell; a battery cell module, accommodated in the shell and electrically connected to the terminal assembly, the battery cell module comprising a plurality of cylindrical battery cell units; wherein at least one of the plurality of battery cell units is a test battery cell; a temperature detection element is provided at one end of the test battery cell, and the temperature detection element is configured to detect the temperature of the electrode tab of the test battery cell.

[0074] In some embodiments, the test cell is substantially located at the center of gravity of the cell module.

[0075] In some embodiments, the battery pack further includes a battery management unit, and the battery management unit communicates with the temperature detection element via a communication line.

[0076] In some embodiments, the test cell is a full-tab battery.

[0077] In some embodiments, the temperature detection element includes at least a temperature sensor.

[0078] A battery pack comprises: a shell; a terminal assembly, arranged in the shell; a battery cell module, accommodated in the shell and electrically connected to the terminal assembly, the battery cell module comprising a plurality of battery cell units, the plurality of battery cell units comprising at least one full-tab battery; a temperature detection element, for obtaining the temperature of the full-tab battery; a battery management unit, arranged in the shell and communicatively connected to the temperature detection element; wherein the battery management unit is configured to: adjust the maximum output power or maximum output current of the battery pack according to the temperature.

[0079] In some embodiments, the temperature detection element is configured to directly detect the temperature of the full-tab battery.

[0080] In some embodiments, the temperature detection element is configured to detect the ambient temperature within the battery pack and estimate the temperature of the full-tab battery according to the ambient temperature.

[0081] In some embodiments, the battery management unit is further configured to: select a charging mode of the battery pack according to the temperature.

[0082] In some embodiments, the battery pack is suitable for powering a riding vehicle.

[0083] In some embodiments, the battery pack is suitable for powering a power tool.

[0084] An electric tool comprises: a housing; a working piece; a motor, arranged in the housing and used to drive the working piece; an energy storage device, mounted to the housing, the energy storage device comprising a plurality of battery cells to supply power to the motor; a drive circuit, arranged in the housing and used to drive the motor, the drive circuit comprising a plurality of semiconductor switches; wherein the battery cells are full-tab batteries, and the resistance of the semiconductor switches is less than or equal to 2 milliohms.

[0085] In some embodiments, the motor includes a stator core and a winding, and a slot fill rate of the winding is greater than or equal to 40%.

[0086] In some embodiments, the motor is a flat wire motor.

[0087] In some embodiments, the semiconductor switch comprises gallium nitride.

[0088] In some embodiments, the power range of the motor is greater than or equal to 0 and less than or equal to 10 kW.

[0089] In some embodiments, the energy storage device is disposed inside the housing.

[0090] In some embodiments, the energy storage device is detachably mounted to the outside of the housing.

[0091] A battery pack for powering an electric tool, comprising: a shell; an electric tool interface for connecting to the electric tool, the electric tool interface comprising a terminal assembly; a battery cell module accommodated in the shell and electrically connected to the terminal assembly, the battery cell module comprising a plurality of battery cell units, the plurality of battery cell units comprising at least one full-tab battery; a magnetic current sensor configured to detect the current of the battery cell module, the magnetic current sensor being disposed in the shell.

[0092] In some embodiments, the terminal assembly includes a first positive terminal, a second positive terminal, a negative terminal, and a communication terminal.

[0093] In some embodiments, the battery pack further includes: a battery cell connecting sheet configured to connect a plurality of battery cell units; the battery cell connecting sheet has an uneven thickness.

[0094] In some embodiments, the thickness of the battery cell connecting piece at the welding portion is smaller than the thickness of the non-welding portion.

[0095] In some embodiments, the magnetic current sensor is arranged on the charging / discharging circuit of the battery module. BRIEF DESCRIPTION OF THE DRAWINGS

[0096] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0097] Figure 1 is a three-dimensional diagram of a battery pack provided by an embodiment of the present application;

[0098] Figure 2a is an exploded view of a battery pack provided by an embodiment of the present application;

[0099] Figure 2b is a schematic diagram of a partial structure of a battery pack provided by an embodiment of the present application;

[0100] Figure 2cIt is a structural schematic diagram of a battery cell connecting sheet provided by an embodiment of the present application;

[0101] Figure 2d It is a structural schematic diagram of a battery cell connecting sheet provided by an embodiment of the present application; Figure 3 It is a schematic diagram of a battery pack terminal charging and discharging port provided by an embodiment of the present application;

[0102] Figure 4 This is an example diagram of an electric tool to which a battery pack provided by an embodiment of the present application is applicable;

[0103] Figure 5 is an exemplary diagram of a power supply device applicable to a battery pack provided in one embodiment of the present application;

[0104] Figure 6 is a schematic diagram of the structure of a battery cell unit provided by an embodiment of the present application;

[0105] Figure 7 It is a schematic diagram of a tab in an existing battery cell unit provided by an embodiment of the present application;

[0106] Figure 8 is a schematic diagram of a full-tab battery cell unit provided by an embodiment of the present application;

[0107] Fig. 9 This is a schematic diagram of voltage changes of a battery cell unit during the discharge process of a battery pack provided by an embodiment of the present application;

[0108] Fig.10 This is an example diagram of a test cell in a battery pack provided by an embodiment of the present application;

[0109] Fig.11 This is a control circuit diagram of an electric tool used with a battery pack provided in one embodiment of the present application. DETAILED DESCRIPTION

[0110] Before any embodiments of the application are explained in detail, it is to be understood that the application is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the above drawings.

[0111] In this application, the terms "comprises", "includes", "has" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of more restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device that includes the element.

[0112] In this application, the term "and / or" is a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects before and after are in an "and / or" relationship.

[0113] In the present application, the terms "connect", "combine", "couple", and "install" may refer to direct connection, combination, coupling, or installation, or indirect connection, combination, coupling, or installation. For example, direct connection refers to two parts or components being connected together without the need for an intermediate piece, and indirect connection refers to two parts or components being connected to at least one intermediate piece respectively, and the two parts or components being connected via the intermediate piece. In addition, "connect" and "couple" are not limited to physical or mechanical connections or couplings, and may include electrical connections or couplings.

[0114] In the present application, it will be understood by those of ordinary skill in the art that relative terms (e.g., "about," "approximately," "substantially," etc.) used in conjunction with quantities or conditions include the values ​​and have the meaning indicated by the context. For example, the relative terms include at least the degree of error associated with the measurement of a specific value, the tolerances caused by manufacturing, assembly, and use associated with a specific value, and the like. Such terms should also be considered to disclose a range defined by the absolute values ​​of the two endpoints. Relative terms may refer to plus or minus 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. In addition, "substantially" may refer to plus or minus a certain degree (e.g., 1 degree, 5 degrees, 10 degrees or more) on the basis of the indicated angle when expressing a relative angular position relationship (e.g., substantially parallel, substantially perpendicular).

[0115] In this application, it will be understood by those skilled in the art 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 the present application, the terms "upper", "lower", "left", "right", "front", "back" and other directional words are described based on the orientation and positional relationship shown in the accompanying drawings, and should not be understood as limiting the embodiments of the present application. In addition, in the context, it is also necessary to understand that when it is mentioned that an element is connected to another element "upper" or "lower", it can not only be directly connected to another element "upper" or "lower", but also indirectly connected to another element "upper" or "lower" through an intermediate element. It should also be understood that directional words such as upper side, lower side, left side, right side, front side, back side, etc. not only represent the positive orientation, but can also be understood as the lateral orientation. For example, the bottom can include directly below, lower left, lower right, lower front, and lower back, etc.

[0117] In this application, the terms "controller", "processor", "central processing unit", "CPU", and "MCU" are interchangeable. When a unit "controller", "processor", "central processing unit", "CPU", or "MCU" is used to perform a specific function, unless otherwise specified, these functions can be performed by a single unit or multiple units.

[0118] In the present application, the terms “device”, “module” or “unit” may be implemented in the form of hardware or software to achieve specific functions.

[0119] In this application, the terms "calculate", "judge", "control", "determine", "identify", etc. refer to the operations and processes of a computer system or similar electronic computing device (e.g., controller, processor, etc.).

[0120] refer to Figure 1 The battery pack 100 shown in FIG2 mainly includes a shell 11, an interface 12, and a battery cell module 13. In the present application, the interface 12 may also be referred to as a power tool interface, which is mainly used to connect to a power tool. The interface or power tool interface hereinafter may be interchangeable. Among them, the power tool interface 12 includes a terminal assembly 121. The terminal assembly 121 can at least transmit electrical energy between the battery pack 100 and the power tool. In other embodiments, the terminal assembly 121 can also transmit electrical energy between the battery pack 100 and a charger or adapter, or can transmit electrical energy between the battery pack 100 and other electrical devices. In one embodiment, the terminal assembly 121 may include a positive terminal, a negative terminal and a communication terminal, or at least a positive terminal and a negative terminal. The battery cell module 13 is disposed in the shell 11, and can be directly or indirectly electrically connected to the terminal assembly 121. As Figure 2a to Figure 2d The battery cell module 13 may include a plurality of battery cell units 131 , and may further include a battery cell support 132 for supporting the battery cell units 131 , and a battery cell connecting sheet 133 for electrically connecting the plurality of battery cell units 131 .

[0121] In this embodiment, the interface 12 may include a first interface 12a and a second interface 12b. The first interface 12a and the second interface 12b may be two completely independent groups of interfaces, or may share some terminal assemblies. In one embodiment, the first interface 12a may include a first terminal assembly 12a1, and the second interface 12b may include a second terminal assembly 12b1, wherein at least some of the components of the first terminal assembly 12a1 and the second terminal assembly 12b1 are the same or different. Exemplarily, the first terminal assembly 12a1 includes a first positive terminal, a negative terminal and a communication terminal, and the second terminal assembly 12b1 includes a second positive terminal, a negative terminal and a communication terminal, that is, the first terminal assembly 12a1 and the second terminal assembly 12b1 share a negative terminal and a communication terminal, but have different positive terminals.

[0122] In one embodiment, the first interface 12a and the second interface 12b can both be used as charging interfaces, for example, they can both be connected to a charger or a mobile power supply or an adapter to use AC power or other battery packs as charging power sources to charge the battery pack 100. In one embodiment, the first interface 12a and the second interface 12b can both be discharge interfaces. In an optional implementation, the output voltage or output power of the two interfaces can be different or the same.

[0123] In one embodiment, the first interface 12a can be configured to connect to an electrical device, such as various power tools or other DC devices, and the second interface 12b is configured to connect to a charging device, such as a charger or a mobile power supply. In other words, the battery pack 100 is a battery pack with different charging and discharging ports. Figure 3 As shown, the battery pack 100 can be connected to the power tool 200 or the charger 300a through the interface 12. The selection switch 121 in the battery pack 100 can control the interface 12 to be the first interface 12a or the second interface 12b according to the different electrical devices connected to the interface 12. In this embodiment, the first interface 12a can be connected to the charger 300a. When the selection switch 121 is closed, the positive terminal p+, c+, the negative terminal p- and the communication terminal D constitute the first interface 12a. The second interface 12b can be connected to the power tool 200. When the selection switch 121 is disconnected, the positive terminal p+, the negative terminal p- and the communication terminal D constitute the second interface 12b.

[0124] In this embodiment, a plurality of different types of electric tools 200 can be powered by the battery pack 100 . Figure 4Several common power tools are illustrated, such as a riding lawn mower 200a, an electric drill 200b, a chain saw 200c, a grass trimmer 200d, and a hair dryer 200e. It should be noted that the power tool 200 can also be a handheld power tool, such as a drill, a pruning machine, a sander, etc. Alternatively, the power tool 200 can also be a bench tool, such as a bench saw, a miter saw, etc. Alternatively, the power tool 200 can also be a hand-push power tool, such as a hand-push lawn mower, a hand-push snow blower. Alternatively, the power tool 200 can also be a riding power tool, such as a riding lawn mower, a riding vehicle, an all-terrain vehicle, etc. Alternatively, the power tool 200 can also be a robot tool, such as a lawn mowing robot, a snow sweeping robot, etc. In some embodiments, the power tool 200 can be an electric drill, an electric light, an electric car, etc. In some embodiments, the power tool 200 can also be a garden tool, such as a pruning machine, a hair dryer, a lawn mower, a chain saw, etc. Alternatively, the power tool 200 may also be a decoration tool, such as a screwdriver, a nail gun, a circular saw, a sander, etc. In some embodiments, the power tool 200 may also be a vegetation care tool, such as a lawn mower, a lawn mower, a pruner, a chain saw, etc. Alternatively, the power tool 200 may also be a cleaning tool, such as a hair dryer, a snow sweeper, a cleaning machine, etc. Alternatively, the power tool 200 may also be a drill tool, such as a drill, a screwdriver, a wrench, an electric hammer, etc. Alternatively, the power tool 200 may also be a saw tool, such as a reciprocating saw, a jig saw, a circular saw, etc. Alternatively, the power tool 200 may also be a bench tool, such as a bench saw, a miter saw, a metal cutter, a bakelite milling machine, etc. Alternatively, the power tool 200 may also be a grinding tool, such as an angle grinder, a sander, etc. Alternatively, the power tool 200 may also be other tools, such as a lamp, a fan, etc.

[0125] The power tool 200 powered by the battery pack 100 may have a battery pack mounting portion for mounting the battery pack 100. In one embodiment, the battery pack 100 is detachably mounted to the housing 201 of the power tool 200. In one embodiment, the battery pack 100 is fixedly mounted in the accommodating cavity formed by the housing 201, that is, the battery pack 100 is built into the power tool 200.

[0126] The battery pack 100 can also be connected to Figure 5 The mobile power supply 300 shown. The mobile power supply 300 can be used as a small mobile power station, which can be connected to the power grid, or to a car charging pile, or to a photovoltaic charging panel to obtain charging power. The mobile power supply 300 can be provided with an energy storage device such as a battery pack or a capacitor. The mobile power supply 300 can also have a DC output interface or an AC output interface, which can output DC power supply power or AC power supply power.

[0127] In this embodiment, the mobile power supply 300 can also be detachably connected to the battery pack 100. The mobile power supply 300 can charge the connected battery pack 100, and can also use the electric energy of the battery pack 100 to reversely charge the energy storage device in the mobile power supply 300. In other words, the battery pack 100 can supply power to the mobile power supply 300, and can also obtain electric energy from the mobile power supply 300. In one embodiment, the battery pack 100 can be connected to the shell of the mobile power supply 300, or connected to the closed or semi-closed accommodating cavity formed by the shell of the mobile power supply 300. This embodiment does not specifically limit the structural form of the mobile power supply 300 as a mobile power station.

[0128] The battery pack 100 is a kind of energy storage element, and the battery cell 131 therein can be called a core component. The structure or composition of the battery cell 131 directly affects the output characteristics of the battery pack 100. In this embodiment, the battery cell 131 is as follows: Figure 6 The battery shown may be a cylindrical battery, which may include an anode 1311, a cathode 1312, an electrolyte 1313, and a cylindrical shell 1317. In one implementation, the anode 1311 and the cathode 1312 are longitudinally wound together to form a battery cell. In the wound configuration, the electrolyte 1313 is disposed between the opposing surfaces of the anode 1311 and the cathode 1312. In one embodiment, the electrolyte 1313 may be an organic solvent, a solid electrolyte, a lithium ion liquid electrolyte, or a polymer electrolyte. The anode 1311 and the cathode 1312 may be formed of appropriate materials, for example, the cathode and the anode may include a sheet or panel coated with or formed of a lithium oxide alloy or a lithium compound. In one embodiment, the anode 1311 and the cathode 1312 may include a sheet or panel of graphite, graphene, silicon, or silicon oxide.

[0129] In order to conduct the electric energy of the battery cell 131, the battery cell 131 further includes a tab 1314 connected to the anode 1311 and the cathode 1312, which can conduct the electricity in the battery cell 131. Figure 7 In the illustrated single-pole battery, the tab 1314 can be configured as an electrode material on the extended length of the longitudinal edge of the battery cell 131. Exemplarily, a protrusion or a grooved design or a toothed design of a conductive sheet material beyond the coating material of the anode 1311 or the cathode 1312 can be configured as the tab 1314.

[0130] Figure 7 The structure of the battery cell 131 shown can be wound along the winding direction shown by the arrow to form a single battery. After winding, the two ends of the battery cell 131 transmit electrical energy through the tabs 1314. Figure 6 and Figure 7As shown, the battery cell unit 131 may further include a positive terminal cap 1315 and a negative terminal cap 1316, wherein the positive terminal cap 1315 is electrically connected to the pole ear 1314 of the anode 1311, and the negative terminal cap 1316 is electrically connected to the pole ear 1314 of the cathode 1312. The battery cell connecting piece 133 may connect the positive terminal caps 1315 or the negative terminal caps 1316 of a plurality of battery cell units 131, thereby electrically connecting the plurality of battery cell units 131.

[0131] The battery tabs 1314 are generally designed to be one or more, which to a certain extent limit the size of the electrical energy conduction path, thereby affecting the output characteristics of the battery pack 100, such as affecting the output power or discharge rate or overcurrent capability of the battery pack 100.

[0132] In the embodiment of the present application, the battery cell unit 131 is a full-tab battery. Figure 8 As shown, the tab 1314 of the full-tab battery is configured as a conductive plate continuously arranged in the full length direction of the longitudinal extension of the anode 1311 or the cathode 1312. In other embodiments, the full-tab battery can also be called a tab-free battery. The full-tab battery unit or full-tab battery cell in this embodiment can be understood as a full-tab battery.

[0133] In this embodiment, the continuous discharge power of the full-electrode battery cell 131 is greater than or equal to 300W. In other embodiments, the continuous discharge power of the battery cell 131 is greater than or equal to 350W, or greater than or equal to 400W, or greater than or equal to 500W. In this embodiment, the instantaneous discharge power of the battery cell 131 is greater than or equal to 550W, or greater than or equal to 600W, or greater than or equal to 650W. In other words, the full-electrode battery cell 131 in the present application can provide a larger instantaneous power or continuous discharge power, so as to adapt to the power requirements of different power tools under different working conditions.

[0134] Since the full-tab battery unit 131 has a strong discharge capacity, in order to prevent the heat generated by the battery unit 131 from being unable to be promptly discharged due to continuous high current discharge, the minimum distance between the battery units 131 can be set to be greater than or equal to 2 mm, or greater than or equal to 2.5 mm, or greater than or equal to 3 mm. In this embodiment, the minimum distance between the battery units 131 can be the minimum distance between adjacent battery units 131 in the horizontal or vertical direction.

[0135] In one embodiment, the diameter of the full-tab battery cell 131 is greater than or equal to 3 cm, for example, the diameter of the full-tab battery cell 131 is 3 cm, 3.5 cm or 4 cm, etc. In one embodiment, the diameter of the full-tab battery cell 131 is greater than or equal to 4 cm, for example, it can be 4.5 cm, 4.6 cm or 5 cm, etc. In this embodiment, the height of the full-tab battery cell 131 is greater than or equal to 8 cm, for example, the height of the full-tab battery cell 131 is 8 cm, 9 cm, 10 cm, 11 cm, 12 cm, 13 cm or 13.5 cm, etc.

[0136] By adopting full-pole ears, the ability of the electrode to transmit electrical energy is increased, and the internal resistance of the battery cell 131 is reduced. Exemplarily, the internal resistance of the battery cell 131 is less than or equal to 10mΩ, or less than or equal to 9mΩ, or less than or equal to 8mΩ, or less than or equal to 7mΩ, or less than or equal to 6mΩ, or less than or equal to 5mΩ. In this embodiment, the battery cell 131 can be a 4680 battery cell. In one embodiment, the energy density of the battery cell 131 is greater than or equal to 600Wh / L, or greater than or equal to 620Wh / L, or greater than or equal to 650Wh / L, or greater than or equal to 660Wh / L, or greater than or equal to 680Wh / L, or greater than or equal to 700Wh / L. In this embodiment, in order to match the discharge capacity of the battery cell 131, the battery cell connection sheet 133 connecting multiple battery cells 131 can be locally thickened. In one embodiment, the thickness of the battery cell connection sheet 133 at the connection between the battery cell connection sheet 133 and the battery cell 131 is less than the thickness at the non-connection. In one embodiment, the ratio of the thickness of the cell connection sheet 133 at the connection between the cell connection sheet 133 and the cell unit 131 to the thickness at the non-connection is less than 1, or less than 0.8, or less than 0.6, or less than 0.5, etc. In one embodiment, the cell connection sheet 133 can be connected to the cell unit 131 by welding, and the number of welding points or welding points at the welding point is greater than or equal to 2, or is continuous welding without breakpoints, or is less than or equal to 8, which can ensure the overcurrent capacity of the connection. In one embodiment, in order to enhance the overcurrent capacity of the cell connection sheet 133, a reinforcing piece 1331 can be provided on the non-welding surface 133a of the cell connection sheet 133, such as Figure 2c and Figure 2dAs shown. Among them, the non-welding surface 133a of the battery cell connecting sheet 133 can be understood as a side away from the battery cell unit 131 to which it is connected. Alternatively, based on the connection of the battery cell connecting sheet 133 to the battery cell unit 131, the side of the battery cell connecting sheet 133 directly connected to the battery cell unit 131 is defined as the welding surface 133b, and the other side opposite to the welding surface is defined as the non-welding surface 133a. In other words, the non-welding surface 133a of the battery cell connecting sheet 133 is not in direct contact or in other words, not in contact with the battery cell unit 131 to which it is connected. In the present application, the welding surface 133a and the non-welding surface 133a of the battery cell connecting sheet 133 are only used to distinguish and define whether it is in direct contact with the connected battery cell unit 131, and does not mean that welding is not performed on the non-welding surface 133a or that welding is performed on the welding surface 133b.

[0137] In one embodiment, the reinforcing member 1331 may be a metal member or a metal coating disposed on the non-welding surface 133a. For example, it may be a copper sheet or a copper coating, or may be other types of metal sheets or coatings. In one embodiment, the reinforcing member 1331 may be disposed on the non-welding surface 133a by welding, rolling, or a composite process or other processes.

[0138] In one implementation, the surface shape of the reinforcement member 1331 is as follows: Figure 2c Different from the surface shape of the cell connecting piece 133, the reinforcing piece 1331 can be welded to the non-welding surface 133a of the cell connecting piece 133 by resistance welding or laser welding, so as to form a cell connecting piece assembly with stronger overcurrent capability and better heat dissipation performance.

[0139] In one implementation, the surface shape of the reinforcement member 1331 is as follows: Figure 2d The surface shape of the cell connection sheet 133 is consistent with that of the cell connection sheet 133, that is, the reinforcing piece 1331 can be completely attached to the non-welding surface 133a of the cell connection sheet 133 to form a cell connection sheet assembly having two layers of metal components. In this embodiment, the reinforcing piece 1331 can be processed onto the non-welding surface 133a by rolling or other composite processes.

[0140] In one embodiment, the thickness of the reinforcing piece 1331 is greater than or equal to 0.1 mm and less than or equal to 2 mm. In one embodiment, the thickness of the reinforcing piece 1331 is greater than or equal to 0.5 mm and less than or equal to 1 mm. In one embodiment, the thickness of the reinforcing piece 1331 is greater than or equal to 0.1 mm and less than or equal to 0.5 mm. Exemplarily, the thickness of the reinforcing piece 1331 can be 0.1 mm, or 0.3 mm, or 0.5 mm, or 0.8 mm, or 1 mm, or 1.2 mm, etc.

[0141] In one embodiment, the cell connection sheet 133 is made of a different material than the reinforcing member 1331, for example, the reinforcing member 1331 is made of copper, while the cell connection sheet 133 is made of nickel. Alternatively, the reinforcing member 1331 is made of copper, while the cell connection sheet 133 is made of a nickel alloy, such as NB109.

[0142] In this embodiment, the contact impedance or welding internal resistance between the battery cell connection sheet 133 and the battery cell unit 131 is less than or equal to 10 μΩ. Therefore, the temperature rise rate of the battery pack is relatively slow during the charging or discharging process of the battery pack.

[0143] In this embodiment, when the battery pack is continuously discharged at a current of 100 A for 30 seconds, the temperature rise of the cell connection sheet 133 is less than or equal to 120° C. Therefore, the cell connection sheet 133 can meet the discharge or charge requirements of the full-tab battery.

[0144] In this embodiment, in order to better dissipate heat for the battery cell unit 131, a heat dissipation structure 14 is further provided in the battery pack 100. Figure 6 As shown, the heat dissipation structure 14 can be arranged at the positive terminal cover 1315 or the negative terminal cover 1316 near the battery cell unit 131 to enhance the heat dissipation capacity of the pole ear 1314. In this embodiment, the minimum straight-line distance between the heat dissipation structure 14 and the pole ear 1314 of the anode or cathode is less than or equal to 0.5 cm, or less than or equal to 1 cm, or less than or equal to 1.5 cm. In one embodiment, the heat dissipation structure 14 may include a busbar that can divert the heat dissipated by the battery cell unit 131, and the busbar at the connection with the pole ear 1314 is at least partially configured as a channel of a wavy shape or other shapes such as a serrated shape to increase the exhaust path of hot air. In this embodiment, the heat dissipation structure 14 may include at least one heat dissipation material selected from nickel strip, copper, and nickel-plated copper. In one embodiment, the heat dissipation structure 14 may also be a hydrogel.

[0145] In this embodiment, the battery cell units 131 of the battery pack 100 are partially or entirely configured as full-tab batteries, which greatly improves the power density of the battery pack 100. In one embodiment, the output power density of the battery pack 100 is greater than or equal to 1500W / kg, or greater than or equal to 1600W / kg, or greater than or equal to 1700W / kg, or greater than or equal to 1800W / kg, or greater than or equal to 1900W / kg, or greater than or equal to 2000W / kg. In this embodiment, the number of full-tab batteries in the battery pack 100 is greater than or equal to 10, or greater than or equal to 15, and the continuous discharge power of any full-tab battery is greater than or equal to 300W.

[0146] Under certain conditions, the battery pack 100 can be fast charged. For example, when the remaining power of the battery pack 100 is less than or equal to the first threshold, the charging rate of the battery pack 100 is greater than or equal to 4C and less than or equal to 10C. The first threshold may be the percentage of the remaining power of the battery pack 100 to the total power of the battery pack. The threshold may be any value between greater than or equal to 70% and less than or equal to 90%, for example, 70%, 75%, 80%, 85%, 90%, etc.

[0147] In one embodiment, a power interface can be provided in the riding lawn mower so as to be connected to at least the battery pack 100, so that the battery pack 100 can power the riding lawn mower. Among them, the battery cell unit 131 in the battery pack 100 is a full-tab battery. In this embodiment, the battery pack 100 may also be referred to as a first energy storage device, and the output power density of the energy storage device is greater than or equal to 1500W / kg. In an optional implementation, the riding lawn mower may also be configured with a second energy storage device different from the first energy storage device, and the second battery cell unit in the second energy storage device may be a non-full-tab battery. The power density of the second energy storage device is less than the power density of the first energy storage device.

[0148] In one embodiment, the mobile power supply 300 can also charge the battery pack 100, and when the remaining power of the battery pack 100 is less than or equal to the first threshold, the charging rate of the battery pack 100 is greater than or equal to 4C and less than or equal to 10C. The first threshold may be a percentage of the remaining power of the battery pack 100 to the total power of the battery pack, and the threshold may be any value between greater than or equal to 70% and less than or equal to 90%, for example, 70%, 75%, 80%, 85%, 90%, etc.

[0149] In one embodiment, the adapter can also be connected to AC mains to charge the battery pack 100. When the remaining power of the battery pack 100 is less than or equal to the first threshold, the charging rate of the battery pack 100 is greater than or equal to 4C and less than or equal to 10C. In this embodiment, the adapter can be connected to AC mains to use AC power as the charging power source for charging the battery pack 100, or can be connected to other energy storage devices to use DC power as the charging power source for charging the battery pack 100.

[0150] In this embodiment, the battery pack 100 can supply power to electrical devices at a maximum discharge rate of 20C or more and 50C or less, for example, to various power tools or to a mobile power supply 300. Exemplarily, the maximum discharge rate of the battery pack 100 is 20C, 25C, 30C, 35C, 40C, 45C, 50C, etc. In this embodiment, the battery pack 100 includes a maximum of 7 full-tab batteries, or the battery pack 100 includes a maximum of 8 full-tab batteries, or the battery pack 100 includes a maximum of 9 full-tab batteries, or the battery pack 100 includes a maximum of 10 full-tab batteries, etc. In some embodiments, the number of full-tab batteries in the battery pack 100 can be set according to the rated voltage of the battery pack 100 to be set.

[0151] In one embodiment, due to the small internal resistance and strong overcurrent capability of the full-pole-ear battery, the voltage drop of the cell unit 131 is small during the discharge process of the battery pack 100. Exemplarily, when the remaining power of the battery pack 100 is greater than or equal to 50% and is discharged to the electrical equipment at a discharge rate greater than or equal to 2C at a preset temperature, the voltage drop of the cell unit 131 is less than or equal to 90mV, or less than or equal to 100mV, or less than or equal to 110mV, or less than or equal to 120mV. The preset temperature may be room temperature or normal temperature, for example, a temperature of about 20°C, or a temperature of about 25°C, or a temperature of about 30°C. In this embodiment, the range of the preset temperature may be any temperature or a temperature interval within the temperature range of -20°C-60°C. In one embodiment, on the basis that the preset temperature is basically the same and the discharge rate is basically the same, the greater the remaining power of the battery pack 100, the smaller the voltage drop of the cell unit 131 during the discharge process. For example, when the remaining power of the battery pack 100 is greater than or equal to 70% and is discharged to an electrical device at a discharge rate greater than or equal to 2C at a preset temperature, the voltage drop of the battery cell 131 is less than or equal to 80 mV, or less than or equal to 85 mV.

[0152] refer to Fig. 9 The figure shows the voltage variation of the battery cell 131 during the discharge process of the battery pack 100. Fig. 9The figure shows the remaining power of the battery pack 100 of 70%, 50%, and 30%, respectively, and the voltage change of the battery cell 131 during the discharge process at a preset temperature and a discharge rate greater than or equal to 2C. Among them, line 1 represents the voltage change of the battery cell 131 when the remaining power of the battery pack 100 is 70% and discharged, line 2 represents the voltage change of the battery cell 131 when the remaining power of the battery pack 100 is 70% and discharged, and line 3 represents the voltage change of the battery cell 131 when the remaining power of the battery pack 100 is 70% and discharged. It can be seen from the figure that the more the remaining power of the battery pack 100, the smaller the voltage drop of the battery cell 131 during the discharge process, and the voltage drop of the battery cell 131 during the voltage plateau period of discharge is smaller than the voltage drop during the non-voltage plateau period.

[0153] In this embodiment, at least one of the multiple battery cells 131 in the battery pack 100 is set as a test battery cell, and a temperature detection element 15 is provided at one end of the test battery cell to detect the temperature of the test battery cell. In this embodiment, the temperature of the test battery cell can be basically considered to be the internal temperature of the battery pack 100, or the temperature of the test battery cell is basically the temperature of the battery cell module 13. Fig.10 As shown, one or more battery cells 131 in the rectangular frame can be set as test cells, and the test cells are basically located at the geometric center of the battery cell module 13, or basically located at the center of gravity of the battery cell module 13. In one embodiment, the test cell is basically consistent with other battery cells 131 or the test cell is more sensitive to temperature changes, and its temperature can better represent the temperature in the battery pack 100. For example, the material in the test cell is more sensitive to temperature changes and is more easily detected by the temperature detection element 15.

[0154] In this embodiment, the test cell is a full-tab battery, and the temperature detection element 15 can at least detect the temperature of the full-tab battery. Alternatively, the temperature detection unit 15 can also detect the temperature of other full-tab batteries in the battery pack 100. In one embodiment, the temperature detection element 15 can be set at one end of the full-tab battery or at any circumferential position of the full-tab battery, or inside the full-tab battery to directly detect the internal temperature of the battery.

[0155] The battery pack 100 also includes a battery management unit (not shown), which is mainly used to manage the charge / discharge of the battery pack 100. In this embodiment, the temperature detection element 15 can communicate with the battery management unit through a communication line to transmit temperature data to the battery management unit. The temperature data can be the temperature of the test cell or the temperature of any full-tab battery in the battery pack. The battery management unit can determine whether the battery pack 100 is at risk of overheating based on the acquired temperature data, or control the charge / discharge rate of the battery pack based on the temperature, or control the battery pack to start charging / discharging or stop charging / discharging based on the temperature, or estimate the internal core temperature of the battery cell unit 131 based on the temperature data, or adjust the maximum output power or maximum output current of the battery pack 100 based on the temperature data, or select different charging modes or discharging modes based on the temperature data.

[0156] In one embodiment, the temperature detection element 15 can be a temperature measuring resistor, a temperature sensor, or a thermocouple.

[0157] In one embodiment, a magnetic current sensor (not shown) is also provided in the battery pack 100, which can at least non-destructively detect or monitor the charge / discharge current of the battery module 13. In one implementation, the magnetic current sensor can be electrically connected or communicatively connected to the battery management unit, and can transmit current data to the battery management module. In this embodiment, the magnetic current sensor can be arranged on the charge / discharge circuit of the battery module 13, for example, at the power input end or power output end of the charge / discharge.

[0158] In one embodiment, the weight of the battery pack 100 may be less than or equal to 4kg, and the battery pack 100 can continuously provide the power tool 200 with a power greater than or equal to 6kW, so that the handheld power tool 200 can be lightweight while also having a strong discharge capacity, greatly improving the performance of the handheld power tool. In this embodiment, the weight of the battery pack 100 may also be less than or equal to 3.5kg, or less than or equal to 3kg, etc., and the battery pack 100 can continuously output a power greater than or equal to 6.5kW, or greater than or equal to 7kW. In other embodiments, the weight and continuous output power of the battery pack 100 in the handheld power tool 200 may also be a combination of any of the above parameters, such as a weight less than or equal to 3.4kg, a continuous output power greater than or equal to 6kW, etc. In this embodiment, the handheld power tool 200 may be a handheld garden tool or a home improvement tool, such as a chain saw.

[0159] refer to Fig.11The control circuit diagram of the electric tool 200 shown in the figure, the electric tool 200 may also include a working piece 21, a motor 22, a battery pack interface 23, a drive circuit 24, and a controller 25. Among them, the type of the electric tool 200 is different, and the action piece 21 is also different. For example, the working piece of the lawn mower is a lawn mower blade, and the working piece of the handheld electric drill is a drill bit. The motor 22 can be a brushed motor or a brushless motor. In one embodiment, the motor 22 can be a hub motor. The application does not limit the type of the motor 22. The battery pack interface 23 can at least be connected to the battery pack 100 including a full-tab battery. In this embodiment, the motor 22 includes a stator core and a winding, wherein the slot full rate of the winding is greater than or equal to 40%, or greater than or equal to 45%, or greater than or equal to 50%. In one embodiment, the motor 22 can be a flat wire motor. After using a full-tab battery for power supply, optimizing the motor slot full rate and changing the motor type, the output power of the motor 22 is greater than or equal to 0 and less than or equal to 10kW.

[0160] The output end of the drive circuit 24 is electrically connected to the stator winding of the motor 22, and is used to transfer the current connected from the battery pack interface 23 to the stator windings A, B, and C to drive the motor 22 to rotate. In one embodiment, the drive circuit 24 includes a plurality of switch elements Q1, Q2, Q3, Q4, Q5, and Q6. The gate end of each switch element is electrically connected to the controller 25 for receiving a control signal from the controller 25. The drain or source of each switch element is connected to the stator windings A, B, and C of the motor 22. The switch elements Q1-Q6 receive control signals from the controller 25 to change their respective conduction states, thereby changing the current loaded by the power supply on the stator windings of the motor 22. In one embodiment, the drive circuit 24 can be a three-phase bridge driver circuit including six controllable semiconductor power devices (such as FET, BJT, IGBT, etc.). It can be understood that the above-mentioned semiconductor switch can also be any other type of solid-state switch, such as an insulated gate bipolar transistor (IGBT), a bipolar junction transistor (BJT), etc. In this embodiment, the semiconductor switch includes at least gallium nitride (GaN). The resistance of the semiconductor switch is less than or equal to 2 milliohms, for example, 1 milliohm, or 2 milliohms.

[0161] To drive Fig.10 The motor 22 shown rotates, and the drive circuit 24 has multiple drive states. In different drive states, the speed or direction of the motor 22 can be different. This application does not elaborate on the process of the controller 25 controlling the drive circuit 24 to change different drive states so that the motor 22 obtains different speeds or directions.

[0162] In this embodiment, the battery pack interface 23 can at least connect to the first battery pack and the second battery pack. Part or all of the multiple battery cells in the first battery pack are full-tab batteries, and the multiple battery cells in the second battery pack are non-full-tab batteries. The first battery pack can be referred to as a full-tab battery pack, and the second battery pack can be referred to as a common battery pack. In this embodiment, the number of battery cells in the first battery pack is substantially the same as the number of battery cells in the second battery pack, and the volumes of the first battery pack and the second battery pack are substantially the same.

[0163] The controller 25 can identify the type of battery connected to the battery pack interface 23, and then set the overcurrent protection threshold of the power tool 200 in response to overcurrent protection according to the different connected battery packs. In one embodiment, when the controller 25 identifies that the battery pack connected to the battery pack interface 23 is the first battery pack, the overcurrent protection threshold of the power tool 200 can be set to the first threshold, and when the controller identifies that the battery pack connected to the battery pack interface 23 is the second battery pack, the overcurrent protection threshold of the power tool 200 can be set to the second threshold. The first threshold is greater than or equal to twice the second threshold, that is, the ratio of the first threshold to the second threshold is greater than or equal to 2. In other embodiments, the ratio of the first threshold to the second threshold is greater than or equal to 2.5, or greater than or equal to 3, or greater than or equal to 3.5, etc.

[0164] In one embodiment, the controller 25 can also set the power tool 200 to have different overcurrent protection response times according to different settings of the connected battery pack. The overcurrent protection response time can be understood as the time period from when the controller 25 detects that the working current of the motor 22 is greater than the overcurrent protection threshold to when the overcurrent protection instruction is output, or the time period from when the controller 25 detects that the working current of the motor 22 is greater than the overcurrent protection threshold to when the overcurrent protection measures are taken, or the time period from when the controller 25 receives the overcurrent protection instruction to when the instruction is executed. In one embodiment, when the controller 25 recognizes that the battery pack interface 23 is connected to the first battery pack, the overcurrent protection response time is set to the first duration; when the controller recognizes that the battery pack interface 23 is connected to the second battery pack, the overcurrent protection response time is set to the second duration. The first duration is greater than the second duration.

[0165] Continue to refer Fig.10, the controller 25 can control the motor 22 to brake or control the motor 22 to decelerate. During the motor braking or deceleration process, a feedback current can be generated, and the feedback current can reversely charge the energy storage device connected to the battery pack interface 23. This embodiment does not elaborate on the process of how to generate feedback current during the braking or deceleration of the motor 22. The above-mentioned energy storage device capable of receiving feedback current can be a battery pack 100 including a full-tab battery. In this embodiment, the maximum feedback current that each battery cell 131 in the battery pack 100 can withstand is greater than or equal to 10 amperes, or greater than or equal to 15 amperes, or greater than or equal to 20 amperes.

[0166] The technical features included in each embodiment of the present application can be combined with each other to form new implementation methods, which will not be listed one by one here.

[0167] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the above embodiments do not limit the present application in any form, and any technical solution obtained by equivalent replacement or equivalent transformation falls within the protection scope of the present application.

Claims

1. A battery pack for powering an electric tool, comprising: case; An electric tool interface, configured to connect to the electric tool; A battery cell module is contained in the housing, wherein the battery cell module comprises a plurality of battery cell units; A battery cell connecting sheet, configured to connect at least two of the battery cell units; Wherein, when the battery pack continuously supplies power to the electric tool at a current of 100 A for at least 30 seconds, the temperature rise of the battery cell connecting piece is less than or equal to 120° C.

2. The battery pack according to claim 1, characterized in that: A reinforcing piece is arranged on the non-welding surface of the battery core connecting piece.

3. The battery pack according to claim 2, characterized in that: The reinforcing member includes a metal sheet or a metal coating.

4. The battery pack according to claim 2, characterized in that: The reinforcing member includes a copper sheet or a copper coating.

5. The battery pack according to claim 2, characterized in that: The thickness of the reinforcing piece is greater than or equal to 0.1 mm and less than or equal to 2 mm.

6. The battery pack according to claim 2, characterized in that: The thickness of the reinforcing piece is greater than or equal to 0.2 mm and less than or equal to 1 mm.

7. The battery pack according to claim 1, characterized in that: The number of welding points between the battery cell connecting sheet and the battery cell unit is greater than or equal to 4 and less than or equal to 8.

8. The battery pack according to claim 2, characterized in that: The surface shape of the reinforcing member is different from the surface shape of the battery cell connecting piece.

9. The battery pack according to claim 2, characterized in that: The surface shape of the reinforcing piece is consistent with the surface shape of the battery core connecting piece.

10. The battery pack according to claim 2, characterized in that: The reinforcing member is arranged on the battery cell connecting sheet in a manner including at least one of welding, rolling or composite process.

11. The battery pack according to claim 2, characterized in that: The reinforcing member is made of a material different from the battery cell connecting sheet.

12. A battery pack comprising: case; A battery cell module is contained in the housing, wherein the battery cell module comprises a plurality of battery cell units; A battery cell connecting sheet, configured to connect at least two of the battery cell units; Wherein, the contact impedance between the battery cell connecting sheet and the battery cell unit is less than or equal to 10 μΩ.

13. The battery pack according to claim 12, characterized in that: A reinforcing piece is arranged on the non-welding surface of the battery core connecting piece.

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