Battery pack

Abstract

The application discloses a battery pack. The battery pack comprises a shell, a battery module arranged in the shell and comprising a plurality of battery cells, a battery terminal comprising at least a positive terminal, a negative terminal and a communication terminal, and arranged to electrically connect the battery pack to an external electrical device, a charging electronic switch connected between the positive terminal of the battery module and the positive terminal to control the on-off of a charging circuit, and a discharging electronic switch connected between the negative terminal of the battery module and the negative terminal to control the on-off of a discharging circuit. The application can at least enhance the safety of the battery pack for electric tools.

Description

Technical Field

[0001] This application relates to the field of power tool technology, for example, to a battery pack. Background Technology

[0002] Thanks to advancements in related technologies, handheld tools such as chainsaws, lawnmowers, circular saws, and blowers; tabletop tools such as miter saws and metal cutters; and wheeled tools such as snowplows, ride-on lawnmowers, lawnmower robots, and all-terrain vehicles can now be powered by lithium batteries. A key issue when using lithium batteries is safety, and a crucial aspect of safety is power failure protection.

[0003] This section provides background information related to this application, which is not necessarily prior art. Summary of the Invention

[0004] One objective of this application is to solve or at least mitigate some or all of the aforementioned problems. To this end, this application provides a battery pack. To achieve the above objective, this application adopts the following technical solution:

[0005] A battery pack includes: a housing; a battery module disposed within the housing and including multiple battery cells; battery terminals, including at least a positive terminal, a negative terminal, and a communication terminal, configured to electrically connect the battery pack to an external electrical device; wherein a discharge electronic switch is connected at least between the positive terminal and the positive terminal of the battery module to control the on / off state of the discharge circuit; and further includes: a parameter detection module configured to detect electrical parameters of the battery terminals; and a controller configured to control the switching state of the discharge electronic switch based on the electrical parameters.

[0006] In some embodiments, the battery pack further includes: a temperature acquisition module configured to acquire at least the temperature near the battery terminals; and a controller configured to control the switching state of the discharge electronic switch in conjunction with electrical parameters and temperature.

[0007] In some embodiments, electrical parameters include one or more of the following parameters: voltage, current, resistance, and conductance of the communication terminal; capacitance, dielectric constant, conductance, and resistance of the positive and / or negative terminals.

[0008] In some embodiments, the controller is configured to control the discharge electronic switch to turn off to cut off the discharge circuit when the electrical parameters are not within a preset range.

[0009] In some embodiments, the controller is also configured to, in response to a manual restart operation, control the discharge electronic switch to turn on to restore the discharge circuit; and / or, periodically detect whether the current electrical parameters allow the discharge circuit to be restored and, if so, control the electronic switch to turn on.

[0010] In some embodiments, a charging electronic switch is also connected between the positive terminals of the battery module to control the on / off state of the charging circuit.

[0011] In some embodiments, a charging electronic switch is also connected between the negative terminals of the battery module to control the on / off state of the charging circuit.

[0012] In some embodiments, the battery terminals also include a separate detection terminal, which is not electrically connected to an external electrical device.

[0013] In some embodiments, the location of one or more or one or more pairs of detection terminals includes at least one of the following: disposed in the internal accommodating space of the housing; at least part or at least part of the outer surface is exposed to the external environment relative to the housing; or embedded in the housing.

[0014] In some embodiments, at least a portion of the detection terminals are in contact with the external environment outside the battery pack housing.

[0015] In some embodiments, at least some of the detection terminals are not in direct contact with the external environment outside the battery pack housing.

[0016] In some embodiments, electrical parameters include one or more of the following: voltage, current, resistance, conductance, capacitance, and dielectric constant of the detection terminal.

[0017] In some embodiments, the discharge electronic switch and / or charge electronic switch are power electronic switches with bidirectional turn-off characteristics.

[0018] In some embodiments, the battery pack further includes a heat sink configured to dissipate heat from the discharge electronic switch and / or the charge electronic switch, and the heat sink has a thermal conductivity greater than or equal to 0.5 W / (m·K).

[0019] A battery pack includes: a housing; a battery module disposed within the housing, including multiple battery cells; battery terminals, including at least a positive terminal, a negative terminal, and a communication terminal, configured to electrically connect the battery pack to an external electrical device; a control circuit board and an electronic switch disposed on the control circuit board; the electronic switch is connected between the positive terminal and the positive terminal of the battery module, and / or the electronic switch is connected between the negative terminal and the negative terminal of the battery module, and the electronic switch has a bidirectional shutdown characteristic.

[0020] In some embodiments, the electronic switch is configured as a power electronic switch without parasitic diodes.

[0021] In some embodiments, the battery pack further includes a heat sink configured to dissipate heat from the corresponding electronic switch, and the heat sink has a thermal conductivity greater than or equal to 0.5 W / (m·K).

[0022] In some embodiments, the heat sink and its corresponding electronic switch are respectively disposed on two opposite sides of the control circuit board.

[0023] In some embodiments, the heat sink and its corresponding electronic switch are disposed on the same side of the control circuit board, and the heat sink is disposed above the electronic switch.

[0024] A battery pack includes: a housing; a battery module disposed within the housing, comprising multiple battery cells; battery terminals, including at least a positive terminal, a negative terminal, and a communication terminal, configured to electrically connect the battery pack to an external electrical device; wherein, a positive electrical transmission segment of the battery pack is configured between the positive terminals of the battery module; a negative electrical transmission segment of the battery pack is configured between the negative terminals of the battery module; electronic switches for controlling the charging and discharging of the battery pack are respectively connected to the positive and negative transmission segments; and a heat sink configured for heat dissipation of the electronic switches, wherein the thermal conductivity of the heat sink is greater than or equal to 0.5 W / (m·K).

[0025] In some embodiments, the heat sink and its corresponding electronic switch are respectively disposed on two opposite sides of the control circuit board.

[0026] In some embodiments, the heat sink and its corresponding electronic switch are disposed on the same surface of the control circuit board, and the heat sink is disposed above the electronic switch.

[0027] In some embodiments, the heat sink is made of at least one material selected from thermally conductive plastic, thermally conductive metal, and composite thermally conductive material.

[0028] In some embodiments, the electronic switch has a bidirectional turn-off characteristic.

[0029] A battery pack includes: a housing; a battery module disposed within the housing and including multiple battery cells; battery terminals, including at least a positive terminal, a negative terminal, and a communication terminal, configured to electrically connect the battery pack to an external electrical device; a charging electronic switch connected between the positive terminal and the positive terminal of the battery module to control the on / off state of the charging circuit; and a discharging electronic switch connected between the negative terminal and the negative terminal of the battery module to control the on / off state of the discharging circuit.

[0030] In some embodiments, the charging electronic switch and / or discharging electronic switch are configured as power electronic switches with bidirectional shutdown characteristics.

[0031] In some embodiments, the charging electronic switch and / or discharging electronic switch are configured as power electronic switches without parasitic diodes.

[0032] In some embodiments, the battery pack further includes a heat sink configured to dissipate heat from the charging electronic switch and / or the discharging electronic switch, and the heat sink has a thermal conductivity greater than or equal to 0.5 W / (m·K).

[0033] In some embodiments, the heat sink and its corresponding charging electronic switch or discharging electronic switch are respectively disposed on two opposite surfaces of the control circuit board.

[0034] In some embodiments, the heat sink and its corresponding charging or discharging electronic switch are disposed on the same surface of the control circuit board, and the heat sink is positioned above the electronic switch.

[0035] In some embodiments, the battery pack further includes: a parameter detection module configured to detect electrical parameters of the battery terminals; and a controller configured to control the switching states of the charging electronic switch and / or the discharging electronic switch based on the electrical parameters.

[0036] In some embodiments, the battery pack further includes: a temperature sampling module configured to acquire at least the temperature near the battery terminals; and a controller configured to control the switching state of the charging electronic switch and / or the discharging electronic switch in conjunction with electrical parameters and temperature.

[0037] In some embodiments, electrical parameters include one or more of the following parameters: voltage, current, resistance, and conductance of the communication terminals; capacitance, dielectric constant, conductance, and resistance of the positive and / or negative terminals.

[0038] In some embodiments, the controller is configured to turn off the discharge electronic switch and / or the charging electronic switch to cut off the discharge circuit and / or the charging circuit when the electrical parameters are not within a preset range.

[0039] A battery pack includes: a housing; a battery module disposed within the housing and including multiple battery cells; battery terminals, including at least a positive terminal, a negative terminal, and a communication terminal, configured to electrically connect the battery pack to an external electrical device; a charging electronic switch connected between the negative terminal and the negative terminal of the battery module to control the on / off state of the charging circuit; and a discharging electronic switch connected between the positive terminal and the positive terminal of the battery module to control the on / off state of the discharging circuit.

[0040] The technical benefits of this application include at least the improvement in the safety of battery packs for power tools. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of a battery pack and its adapted external electrical equipment, such as power tools and chargers, as one embodiment of this application.

[0042] Figure 2 This is a perspective view of a battery pack as one embodiment of this application;

[0043] Figure 3 yes Figure 2 A 3D view of the battery module in the battery pack shown;

[0044] Figure 4 This is a circuit diagram of a battery pack as an embodiment of this application;

[0045] Figure 5 This is a schematic diagram of a power electronic switch with a parasitic diode as one embodiment of this application;

[0046] Figure 6 This is a side view of the electronic switch and its heat sink as an embodiment of this application on the control circuit board;

[0047] Figure 7 This is a side view of the electronic switch and its heat sink, which are embodiments of this application, on the control circuit board.

[0048] Figure 8 This is a circuit diagram of an electronic switch with bidirectional turn-off characteristics connected between the positive terminals of a module in a battery pack, as an embodiment of this application.

[0049] Figure 9 This is a circuit diagram of an electronic switch with bidirectional turn-off characteristics connected between the negative terminals of a module in a battery pack, as an embodiment of this application.

[0050] Figure 10 This is a circuit diagram of a battery pack in one embodiment of the present application, in which a charging electronic switch is connected between the positive terminals of the module and a discharging electronic switch is connected between the negative terminals of the module.

[0051] Figure 11 This is a circuit diagram of a battery pack in one embodiment of this application, in which a discharge electronic switch is connected between the positive terminals of the module and a charging electronic switch is connected between the negative terminals of the module.

[0052] Attached image caption:

[0053] 100. Battery pack (for power tools); 201. Power tools; 201a. Ride-on lawnmower; 201b. Electric drill; 201c. Hair dryer; 201d. Lawn trimmer; 201e. All-terrain vehicle; 202. Charger;

[0054] 110. Housing; 120. Battery module; 120a. Positive terminal of battery module / module positive terminal; 120b. Negative terminal of battery module / module negative terminal; 121. Cell; 122. Cell support; 123. Cell connector; 130. Battery terminal; 131. Positive terminal; 132. Negative terminal; 133. Communication terminal; 134. Detection terminal; 140. Control circuit board; 141. Controller; 142. Parameter detection module; 143. Temperature sampling module; 150. Electronic switch; 150a. Electronic switch electrically connected to the positive terminal; 150b. Electronic switch electrically connected to the negative terminal; 151. Discharge electronic switch; 152. Charging electronic switch; 160. Heat sink; 101. Discharge circuit; 102. Charging circuit. Detailed Implementation

[0055] 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.

[0056] In this application, the terms "comprising," "including," "having," or any other variations thereof are intended to cover a 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.

[0057] 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.

[0058] 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.

[0059] 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 ​​not using 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.).

[0065] Benefiting from technological advancements, the promotion of environmental protection concepts, and policy support, the power tool industry has continued to expand. After experiencing manual, fuel-powered, and AC-powered stages, the entire sector is now showing a trend towards lithium-ion battery technology and intelligent operation. Various power tools, including handheld tools, benchtop tools, and outdoor power equipment such as snowplows and lawnmowers, can now be powered by battery packs (primarily lithium-ion battery packs). A key aspect of battery safety is power outage protection.

[0066] First, the power tools 201 compatible with the battery pack 100 in this application will be described. These include power tools 201 of different categories, as well as power tools 201 of different models within the same category. For example, they include, but are not limited to, those... Figure 1 The illustrated components include a ride-on lawnmower 201a, a drill 201b, a chainsaw 201c, a lawn mower 201d, a blower 201e, and an all-terrain vehicle 201f. In some embodiments, the power tools 201 adapted to the battery pack 100 may include handheld tools, such as a pruning shear, a circular saw, etc. In some embodiments, the power tools 201 adapted to the battery pack 100 may include benchtop tools, such as a miter saw, a metal cutter, etc. In some embodiments, the power tools 201 adapted to the battery pack 100 may include ride-on tools and / or push-type tools, such as a ride-on lawnmower, a stand-up lawnmower, a push snowplow, etc. In some embodiments, the power tools 201 adapted to the battery pack 100 may include outdoor wheeled tools, such as multi-purpose garden tools and outdoor electric vehicles such as farm vehicles, golf carts, etc. In some embodiments, the power tools 201 adapted to the battery pack 100 may include robotic tools, such as a lawnmower robot, a snowplow robot, etc. Alternatively, in some embodiments, the aforementioned power tool 201 can be a garden tool, including a pruning machine, hair dryer, lawn mower, etc. In some embodiments, the aforementioned power tool 201 can be a decorating tool, including a screwdriver, nail gun, glue gun, sander, etc. In some embodiments, the aforementioned power tool 201 can be a cutting tool, including a jigsaw, chainsaw, reciprocating saw, circular saw, etc. In some embodiments, the aforementioned power tool 201 can be a fastening tool, including a screwdriver, hammer drill, electric drill, etc. In some embodiments, the aforementioned power tool 201 can be a grinding tool, including an angle grinder, sander, etc. In some embodiments, the aforementioned power tool 201 can also be other tools, such as a light bulb, fan, etc. It is understood that, without contradicting the specific solution, the power tool 201 adapted to the battery pack 100 in this application can include more types not shown above.

[0067] Following the preceding text, the power tool 201 and its battery pack 100 may be used in various working conditions, and the possibility of humid environments such as rain, snow, and water accumulation cannot be ruled out. Even if some battery packs 100 have certain sealing protection measures, the interfaces / terminals used to couple the power tool 201, charger 202, or other external electrical equipment are still inevitably exposed. In the aforementioned humid environment, water accumulation or moisture will shorten the creepage distance of the interfaces / terminals of the power tool battery pack 100 and components such as the battery cells 121 inside the battery pack 100, increasing the risk of leakage. This can further lead to corrosion or carbonization of live connectors such as interfaces / terminals and the growth of lithium dendrites inside the battery cells 121, which will not only reduce the lifespan of the battery pack 100 but may also cause dangers such as short circuits and fires. In view of this, in one alternative embodiment of this application, a power tool battery pack 100 that improves upon the above-mentioned problems such as water immersion will be provided. It can judge the relevant situation and then implement corresponding protection measures to optimize the safety and lifespan of the battery pack 100.

[0068] The aforementioned power tool battery pack 100 may include at least a housing 110, a battery module 120, and battery terminals 130. The housing 110 forms the main external structure of the battery pack 100 and has an internal accommodating space where the battery module 120 is housed. The battery terminals 130 are disposed on the housing 110, penetrating the housing 110 for electrical connection with the battery module 120, and are at least partially exposed to the outside relative to the housing 110 for coupling with external electrical equipment. Other components, such as the parameter detection module 142 and the controller 141 described later, may also be accommodated, supported, and limited by the housing 110.

[0069] The battery pack 100 uses a battery module 120 within the casing 110 to store electrical energy. The battery module 120 may include multiple cells 121, which may be connected in series, in parallel, or in a mixed series-parallel relationship. For example, n cells 121 are connected in series to form a cell group 121 (referred to as 1P), and m cell groups 121 are connected in parallel to form the battery module 120, where n and m are positive integers. It should be noted that regardless of how the multiple cells 121 are connected in series, in parallel, or in a series-parallel manner, they will ultimately have a common positive terminal and a common negative terminal as the unified connection point for the battery module 121 composed of these multiple electrically connected cells 121 to the outside world. The positive terminal 120a of the battery module 120 will be electrically connected to the positive terminal 131, which will be described later, and the negative terminal 120b of the battery module 120 will be electrically connected to the negative terminal 132, which will be described later. In some embodiments, the aforementioned cell 121 can be a cylindrical cell 121; in other embodiments, the aforementioned cell 121 can be a pouch cell 121; and in still other embodiments, the aforementioned cell 121 can be a prismatic cell 121. In some embodiments, the aforementioned cell 121 can be a multi-tab or all-tab cell 121. In some embodiments, the aforementioned cell 121 can be a lithium-ion battery, exemplarily including a ternary lithium battery cell 121, a lithium iron phosphate battery cell 121, etc.; or, the aforementioned cell 121 can also be other cell types 121, exemplarily including nickel-metal hydride batteries, lead-acid batteries, etc. In some embodiments, the battery module 120 further includes a cell support 122 for supporting and limiting the aforementioned plurality of cells 121. Exemplarily, the cell support 122 can be made of modified plastics, etc., and preferably, the material of the cell support 122 can have a high thermal conductivity. In some embodiments, the battery module 120 further includes a cell connecting piece 123 for connecting the plurality of cells 121 in series, parallel, or series-parallel configurations. Exemplarily, the cell connecting piece 123 may be made of copper, aluminum, nickel, or their alloys or composite materials. In some embodiments, positive and negative electrode lines (electrodes) are further provided between the battery module 120 and the battery terminal 130, including a positive electrode line (electrode) between the module positive electrode 120a and the positive terminal 131, and a negative electrode line (electrode) between the module negative electrode 120b and the negative terminal 132.

[0070] The battery module 120 uses battery terminals 130 on the housing 110 to couple with external electrical devices for power supply between them. The battery terminals 130 may include at least a positive terminal 131 and a negative terminal 132 for transmitting electrical energy, and a communication terminal 133 for transmitting data. The battery terminals 130 are coupled with the tool terminals of the power tool 201, the charging terminals of the charger 202, or the device terminals of other external electrical devices to perform charging and discharging. This coupling can be achieved through mechanical contact such as interface plugging. For example, the aforementioned battery terminals 130 are located in terminal blocks on the housing 110 of the battery pack 100. In some embodiments, the housing 110 of external electrical devices such as the power tool 201 and charger 202 has a battery mounting portion for docking with the battery pack 100. This portion can be open or semi-open, or it can be a battery compartment.

[0071] refer to Figure 4 To address and improve the water immersion safety issue of the aforementioned battery pack 100, the power tool battery pack 100 includes a discharge electronic switch 151 for controlling the on / off state of the discharge circuit 101, electrically connected at least between the positive terminal 120a and the positive terminal 131 of the battery module 120. Simultaneously, it also includes a parameter detection module 142 and a controller 141. The parameter detection module 142 can detect the electrical parameters of the battery terminal 130, and the controller 141 can perform corresponding control on the switching state of the discharge electronic switch 151 based on these electrical parameters. Specifically, as shown... Figure 4 As shown, the discharge electronic switch 151 is connected between the positive terminal 120a and the positive terminal 131 of the battery module 120. When the discharge electronic switch 151 is in the ON state (as opposed to an open circuit, meaning the switch is closed or conducting), the discharge current can flow from the positive terminal 120a of the battery module 120 to the positive terminal 131, and the battery pack 100 can discharge to external electrical equipment. When the discharge electronic switch 151 is in the OFF state, the discharge current cannot flow from the positive terminal 120a of the battery module 120 to the positive terminal 131, and the discharge circuit 101 between the battery pack 100 and the external electrical equipment is cut off. The discharge electronic switch 151 is also connected to the controller 141, which is also connected to the parameter detection module 142. The controller 141 receives and determines whether the battery pack 100 is submerged in water based on the electrical parameters of the battery terminal 130 currently measured by the parameter detection module 142. Based on the determination result, the controller transmits a corresponding signal to the discharge electronic switch 151 to control it to be in the corresponding on or off state. For example, if it is determined that there is no water immersion, a high-level signal can be transmitted to the discharge electronic switch 151 to control it to be in the on state, thereby making the discharge circuit 101 between the battery pack 100 and the external electrical equipment conductive. If it is determined that there is water immersion, a low-level signal can be transmitted to the discharge electronic switch 151 to control it to be in the off state, thereby making the discharge circuit 101 between the battery pack 100 and the external electrical equipment disconnected.

[0072] This embodiment grants the battery pack 100 the autonomy to decide whether to discharge externally. Compared to some solutions where external electrical equipment such as the power tool 201 determines whether the battery pack 100 needs to discharge, this allows for the smooth disconnection of the discharge (charge / discharge) circuits 101 and 102 in case of external equipment malfunction. Furthermore, the discharge electronic switch 151, located between the module's positive terminal 120a and the positive terminal 131, controls the on / off state. Compared to some solutions that interrupt the power transmission path between the module's negative terminal 120b and the negative terminal 132, this avoids the connection between the positive terminal 131 and the communication terminal. The creepage and leakage problem between terminals 133 (because communication terminal 133 is still a low-voltage terminal to which current can flow compared to positive terminal 131); crucially, the power tool battery pack 100 in this embodiment will intelligently judge and control whether there is a risk of water immersion in the current battery pack 100 based on the voltage, conductance, capacitance and other electrical parameters of the battery terminals 130 measured in real time, which can effectively avoid safety risks such as short circuits and fires, improve the life of the battery pack 100, and ensure that the battery pack 100 and the power tool 201 can be used safely in various working conditions / environments.

[0073] In some embodiments, the controller 141 determines whether the battery pack 100 is submerged in water by checking whether the electrical parameters of the battery terminal 130 are abnormal. For example, the controller 141 can determine whether the measured electrical parameters of the battery terminal 130 exceed the corresponding threshold or whether they are within the corresponding value range (of course, exceeding the threshold means not being within the preset value range). If the measured value exceeds the threshold or is not within the value range, it can be determined that the battery pack 100 has a safety hazard such as water immersion, and output a signal to turn off the discharge electronic switch 151 and then cut off the discharge circuit 101. Conversely, it can output a signal to turn on the discharge electronic switch 151 and then conduct or allow the discharge circuit 101 to conduct. In some embodiments, the controller 141 makes a judgment based on a single parameter and its threshold or numerical range; in other embodiments, the controller 141 makes a judgment based on multiple parameters and their respective thresholds or numerical ranges, and can control the electronic switch to turn off when any parameter is abnormal or the number of abnormal parameters exceeds the allowed number; in still other embodiments, the controller 141 makes a more accurate composite judgment based on the calculated values ​​of multiple parameters and the thresholds or numerical ranges corresponding to the calculated values.

[0074] In some embodiments, the electrical parameters of the battery terminal 130 include one or more of the following parameters: voltage, current, resistance / conductance of the communication terminal 133; capacitance / dielectric constant, conductance / resistance of the positive terminal 131 and / or the negative terminal 132. For example, the voltage value on the communication terminal 133 normally has specifications (logic level standards), such as GND (0V), 3.3V, 5V, etc. If the terminal comes into contact with water, the voltage value may exhibit a value that does not correspond to the aforementioned specifications, for example, a low level exceeding 0.3*VDD or a high level below 0.7*VDD, etc. For example, if the terminal comes into contact with water, its resistance value may also drop below a lower threshold. For example, if the positive terminal 131 or the negative terminal 132 comes into contact with water, the dielectric constant or capacitance value of the positive and negative terminals 131 and 132 may rise above the threshold. Of course, in addition to the aforementioned electrical parameters, other electrical parameters of the terminals that may change due to contact with fluid can also be applied in this embodiment.

[0075] In some embodiments, in addition to the positive terminal 131, negative terminal 132, and communication terminal 133 described above, the battery terminal 130 of the battery pack 100 may also include other terminals. For example, a detection terminal (detection electrode) 134 may be added. Exemplarily, one detection terminal 134 or a pair of detection terminals 134 may be provided (some electrical parameters can be obtained from a pair of terminals), or multiple detection terminals 134 or multiple pairs of detection terminals 134 may be provided. In some embodiments, the aforementioned detection terminal 134 may be disposed in the receiving space inside the housing 110 of the battery pack 100, for example, attached to the inner wall of the housing 110 at a position such as adjacent to the aforementioned positive terminal 131, negative terminal 132, or communication terminal 133. In other embodiments, the aforementioned detection terminal 134 may be embedded in the housing 110 of the battery pack 100, that is, integral with the housing 110, and does not require direct physical contact with the external environment. In some other embodiments, at least a portion or a portion of the outer surface of the aforementioned detection terminal 134 is exposed to the external environment relative to the battery pack 100 housing 110 to sense the external environment. It is understood that when the battery pack 100 is provided with multiple or more pairs of detection terminals 134, the positional relationship between the detection terminals 134 and the housing 110 can include at least one of the three positional relationships described above. This means that some detection terminals 134 can be disposed inside the pack, and / or some detection terminals 134 can be embedded within the housing, and / or some detection terminals 134 can be inserted through the housing. Specifically, when the battery pack 100 is connected to external electrical equipment (such as a power tool 201 or a charger 202), the aforementioned detection terminal 134 is not coupled to other terminals (tool terminals or charging terminals, etc.), but is electrically connected to the controller 141. The controller 141 can switch the switching state of the electronic switch 150 described above based on the electrical parameters of the detection terminal 134, thereby controlling the on / off state of the discharge circuit 101 and / or the charging circuit 102. This ensures the smooth implementation of the relevant scheme without interfering with the original functions of the positive and negative terminals 131 and 132 and the communication terminal 133, and also avoids the influence of power / data interaction on the detection and judgment in the above scheme. In some embodiments, the aforementioned electrical parameters may include at least one of the following: current, voltage, resistance / conductivity, capacitance / dielectric constant of the detection terminal 134.

[0076] In some embodiments, when the controller 141 makes judgments based on the electrical parameters of the battery terminal 130 and their thresholds or numerical ranges, the judgment logic or the type of parameters involved remains unchanged under different temperatures, different operating modes, or different operating stages, but the corresponding thresholds or numerical ranges used may be different to optimize the accuracy of the solution in judging related safety issues. In some embodiments, the battery pack 100 also includes a temperature sampling module 143, which can at least collect the temperature near the battery terminal 130. It is not excluded that the temperature sampling module 143 collects the temperature at multiple points to comprehensively calculate the temperature at the battery terminal 130. The controller 141 will combine the temperature currently measured by the temperature sampling module 143 and the electrical parameters of the battery terminal 130 currently measured by the parameter detection module 142 to determine whether the battery pack 100 is immersed in water, etc. Temperature compensation can be performed using the measured temperature during the calculation, comparison, and judgment process. For example, the aforementioned temperature sampling module 143 may include a thermistor. In other embodiments, the communication terminal 133 may have different expected values ​​in different operating modes. When the signal on the communication terminal 133 is kept at a high level, the controller 141 can compare the measured terminal voltage value with the threshold or numerical range corresponding to the high level. When the signal on the communication terminal 133 is kept at a low level, the measured terminal voltage value can be compared with the threshold or numerical range corresponding to the low level. When the communication terminal 133 transmits square wave data signals, it can simultaneously determine the change state and specific value of the measured terminal voltage value.

[0077] In some embodiments, the controller 141 executes the above detection and control scheme when the battery pack 100 is not connected to an external electrical device or when there is no power transmission or data interaction with the external electrical device. Alternatively, the controller 141 may execute the above detection and control scheme when the battery pack 100 is connected to an external electrical device and is transmitting power and interacting with it. In both cases, the controller 141 can determine how to control the above discharge electronic switch 151 to cut off the discharge circuit 101 when water immersion or other situations occur based on the electrical parameters of the battery terminal 130. Furthermore, the threshold or numerical range corresponding to the electrical parameters used by the controller 141 in the two cases may be different to ensure the accuracy of the relevant control and avoid misjudgment.

[0078] In some embodiments, when the controller 141 has determined that the battery pack 100 is submerged in water and controls the discharge electronic switch 151 to turn off and disconnect the discharge circuit 101, the controller 141 will respond to the user's manual restart operation by controlling the discharge electronic switch 151 to turn on to restore the discharge circuit 101. Alternatively, the controller 141 may perform a secondary detection and judgment based on the current electrical parameters of the battery terminal 130 before or after manually restoring the discharge circuit 101. If there is still a risk of water immersion, the circuit may remain disconnected or be disconnected again. In other embodiments, the controller 141 may also periodically detect and determine whether the current electrical parameters of the battery terminal 130 allow the aforementioned discharge circuit 101 to be restored. This includes both attempting to restore the discharge circuit 101 first and detecting and judging, and directly detecting and judging without restoring the circuit. Then, if the current electrical parameters are not at risk, the controller may control the discharge electronic switch 151 to turn on, thereby realizing the automatic restoration of the battery pack 100's discharge function.

[0079] In some embodiments, the discharge electronic switch 151 can be various types of power electronic switches 150, including silicon transistors, silicon carbide transistors, gallium nitride transistors, gallium arsenide transistors, etc. In some embodiments, the aforementioned power electronic switch 150 can be MOSFETs, JFETs, IGBTs, BiFETs, etc. In some embodiments, the discharge electronic switch 151 may also include relays, thyristors, etc.

[0080] In some embodiments, the discharge electronic switch 151 may have bidirectional shutdown characteristics. When the controller 141 outputs a shutdown signal, the discharge electronic switch 151 can be used to cut off the current path in two directions. For a detailed explanation of the concept and the solution, please continue reading below.

[0081] In some embodiments, the discharge electronic switch 151 is a power electronic switch 150 such as a transistor. When it is determined that the battery pack 100 is not at risk of water immersion, the controller 141 will control the discharge electronic switch 151 to operate in a linear conduction state to enable the battery pack 100 to power external electrical equipment such as the power tool 201. In other words, in the initial stage of discharging the battery pack 100 to external electrical equipment when there is no risk of water immersion, the controller 141 will control the power electronic switch 150, such as the transistor, to operate in the linear region, where it is on but the resistance (R) is low. ds Compared to the resistance (R) in the fully conductive state onThe large current limit restricts the power-on current, thus avoiding or mitigating the problem of arcing upon power-on. In some embodiments, the battery pack 100 serves as the initialization phase for powering on external electrical equipment such as the power tool 201. Specifically, it may include a controller 141 controlling the power electronic switch 150 to transition from a linear conduction state to a fully conduction state. In some embodiments, the controller 141 outputs a PWM wave with a gradually increasing duty cycle to the power electronic switch 150 (gradually transitioning the power electronic switch 150 from a linear conduction state to a fully conduction state) to prevent excessive dv / dt or current in the circuit, thus avoiding damage to the switch or other electronic components.

[0082] In some embodiments, a charging electronic switch 152 for controlling the on / off state of the charging circuit 102 is electrically connected between the positive terminal 120a and the positive terminal 131 of the battery module 120 in the power tool battery pack 100. This switch is also controlled by the output signal of the controller 141 to change its switching state, thereby turning the charging circuit 102 on or off. In some embodiments, the switching state of the discharge electronic switch 151 does not affect the charging circuit 102, and the switching state of the charging electronic switch 152 does not affect the discharge circuit 101. In some embodiments, the charging electronic switch 152 is always on (maintaining an on / closed / conducting state) during discharge, and the discharge electronic switch 152 is always on (maintaining an on / closed / conducting state) during charging. In other embodiments, a charging electronic switch 152 for controlling the on / off state of the charging circuit 102 is electrically connected between the negative terminal 120b and the negative terminal 132 of the battery module 120 in the power tool battery pack 100.

[0083] In one alternative implementation, refer to Figure 11The power tool battery pack 100 includes the aforementioned housing 110, battery module 120, and battery terminals 130. A discharge electronic switch 151, controlling the on / off state of the discharge circuit 101, is electrically connected between the positive terminal 120a and the positive terminal 131 of the battery module 120. A charging electronic switch 152, controlling the on / off state of the charging circuit 102, is electrically connected between the negative terminal 120b and the negative terminal 132 of the battery module 120. This implementation can control water immersion creepage and leakage during the discharge process of the battery pack 100, and also provides overcharge protection functions, further enhancing the safety of the battery pack 100. Separating the positive and negative electrical transmission sections with charging and discharging electronic switches 151 and 152, while maintaining the same charging and discharging port for the battery pack 100, reduces costs compared to solutions using three-terminal fuses and other components, while offering safety, reliability, and flexible control. Furthermore, the design of the electronic switches 150 at both ends also facilitates system heat dissipation and temperature uniformity. In some embodiments, the power tool battery pack 100 further includes a controller 141 and a parameter detection module 142. The parameter detection module 142 can detect the electrical parameters of the battery terminal 130 and transmit them to the controller 141. The controller 141 can switch the switching states of the aforementioned discharge electronic switch 151 and / or charging electronic switch 152 based on the currently measured electrical parameters of the battery terminal 130, thereby controlling the on / off state of the discharge circuit 101 and / or charging circuit 102 of the battery pack 100. In some embodiments, the aforementioned electrical parameters include, but are not limited to, one or more of the following parameters: voltage, current, resistance / conductance of the communication terminal 133; conductance / resistance, capacitance / dielectric constant of the positive terminal 131 and / or negative terminal 132; current, voltage, resistance / conductance, capacitance / dielectric constant of the detection terminal 134. In some embodiments, the battery pack 100 further includes a temperature sampling module 143, which can at least collect the temperature near the battery terminal 130 and transmit it to the controller 141. The controller 141 will combine the currently measured temperature with the electrical parameters of the battery terminal 130 to decide how to control the switching state of the aforementioned discharge electronic switch 151 and / or charging electronic switch 152.

[0084] In one alternative implementation of this application, reference is made to... Figures 5 to 9The power tool battery pack 100 includes a housing 110, a battery module 120, and a battery terminal 130, as well as a control circuit board 140 and at least one electronic switch 150 disposed on the control circuit board 140 for controlling the on / off state of the charging circuit 102 and / or the discharging circuit 101 of the battery pack 100. The electronic switch 150a is connected between the positive terminal 120a and the positive terminal 131 of the battery module 120, and / or the electronic switch 150b is connected between the negative terminal 120b and the negative terminal 132 of the battery module 120. The electronic switch 150 has a bidirectional shut-off characteristic. The bidirectional shutdown characteristic of the electronic switch 150 means that, at least when the electronic switch 150 is in the off state, neither forward nor reverse current can pass through the electronic switch 150. Specifically, when the electronic switch 150 connected between the positive terminal 120a and the positive terminal 131 and / or connected between the negative terminal 120b and the negative terminal 132 of the module is in the off state in response to the signal of the controller 141, due to its bidirectional shutdown characteristic, it can be used to cut off the discharge circuit 101 from the positive terminal 131 (inflow from the negative terminal 132) and also to cut off the charging circuit 102 from the positive terminal 131 (outflow from the negative terminal 132). Thus, in this embodiment, by utilizing the special properties of some electronic switches 150, only one component can simultaneously provide bidirectional power-off protection for charging and discharging, which can save space for the layout design on the control circuit board 140, reduce component losses and system costs, or enhance redundancy protection and further improve the safety of the battery pack 100. It is understood that this embodiment aims to abandon the traditional back-to-back MOSFET (Si MOSFET) approach and instead utilize the inherent characteristics of some electronic switches 150 to solve the problem (as mentioned above, improve circuit board layout, heat dissipation, losses, and costs). The aforementioned electronic switch 150 with bidirectional turn-off characteristics can be a single element rather than a device, component, or sub-circuit composed of two or more elements.

[0085] In some embodiments, the electronic switch 150 with bidirectional turn-off characteristics described above can be a power electronic switch 150 without parasitic diodes. For example, GaN transistors (such as GaN HEMTs), JFETs, etc., can be used, but not those with only unidirectional turn-off characteristics, such as... Figure 5 The MOSFET shown cannot block reverse current due to the presence of its parasitic body diode. For example, a GaN HEMT transistor can be designed with a symmetrical drain-source configuration, where neither forward nor reverse current is allowed to flow between the drain and source when a turn-off signal (simultaneously below the source and drain voltages) is output to the gate; similarly, neither forward nor reverse current is allowed to flow between the drain and source when a turn-off signal (exceeding its upper / lower cutoff voltage limits) is output to the gate of a JFET transistor.

[0086] In some embodiments, the electronic switch 150 has both bidirectional turn-off and bidirectional conduction characteristics, thereby enabling simultaneous control of the on / off state of the battery pack 100 discharge circuit 101 and charging circuit 102 by a single electronic switch 150, achieving technical effects such as reducing the number of components, lowering losses, and reducing costs. For example, taking a GaN HEMT transistor with the aforementioned source-drain symmetrical design, when a conduction signal (a signal higher than a certain value of the source or drain voltage) is output to the gate, both forward and reverse currents between the drain and source are allowed to pass. For example, a JFET transistor can have a natural conductive path (channel) when there is no external voltage applied to the gate.

[0087] In some embodiments, the electronic switch 150 controls the on / off state of the charging circuit 102 and the discharging circuit 101 in response to different signals. Specifically, the electronic switch 150 can: in response to a first signal, the electronic switch 150 cuts off the discharging circuit 101; and in response to a second signal, the electronic switch 150 cuts off the charging circuit 102; simultaneously, the electronic switch 150 can also: in response to a third signal, the electronic switch 150 allows the discharging circuit 101 to conduct; and in response to a fourth signal, the electronic switch 150 allows the charging circuit 102 to conduct. In some embodiments, the aforementioned first signal and second signal can be the same signal, that is, the off state of the electronic switch 150 with bidirectional off characteristics can be triggered by the same signal. In some embodiments, the aforementioned third signal and fourth signal can be the same signal; in other embodiments, the aforementioned third signal and fourth signal can be different signals, and the difference in signals may include the difference in the numerical range of the signal voltage value.

[0088] In some embodiments, the control circuit board 140 is provided with an electronic switch 150a that has bidirectional shutdown and bidirectional conduction characteristics, connected between the positive terminal and the positive terminal 131 of the battery module 120. In other embodiments, the control circuit board 140 is provided with an electronic switch 150b that has bidirectional shutdown and bidirectional conduction characteristics, connected between the negative terminal and the negative terminal 132 of the battery module 120.

[0089] In some embodiments, the control circuit board 140 is further provided with a controller 141 and a parameter detection module 142. The parameter detection module 142 can detect the electrical parameters of the battery terminal 130 and transmit them to the controller 141. The controller 141 can switch the switching state of the electronic switch 150 based on the currently measured electrical parameters of the battery terminal 130, thereby controlling the on / off state of the discharge circuit 101 and / or charging circuit 102 of the battery pack 100. In some embodiments, the aforementioned electrical parameters include at least one of the following: current, voltage, resistance / conductance of the communication terminal 133; capacitance / dielectric constant, conductance / resistance of the positive terminal 131 and / or negative terminal 132; and current, voltage, resistance / conductance of the detection terminal 134. In some embodiments, the battery pack 100 is further provided with a temperature sampling module 143 that can sample the temperature near the battery terminal 130. The controller 141 will combine the currently measured temperature and the electrical parameters of the battery terminal 130 to make a decision on how to control the electronic switch 150 under temperature compensation. In some embodiments, the controller 141 determines whether to turn off the electronic switch 150 based on whether the measured electrical parameters are within a preset value range.

[0090] In some embodiments, the control circuit board 140 is further provided with a heat sink 160 for dissipating heat from the electronic switch 150. The heat sink 160 may be located on two opposite surfaces of the control circuit board 140, separate from the electronic switch 150; alternatively, it may be located on the same surface of the control circuit board 140 as the electronic switch 150, and positioned on the outer side relative to the electronic switch 150 for heat dissipation. In some embodiments, the heat sink 160 of the electronic switch 150 is made of a material with high thermal conductivity, which can be greater than or equal to 0.5 W / (m·K). Further explanation of the concepts and solutions provided below will be available later.

[0091] In one alternative embodiment of this application, the power tool battery pack 100 includes a housing 110, a battery module 120, and battery terminals 130. The section between the positive terminal 120a and the positive terminal 131 of the battery module 120 is designated as the positive electrical transmission section of the battery pack 100, and the section between the negative terminal 120b and the negative terminal 132 of the battery module 120 is designated as the negative electrical transmission section of the battery pack 100. Electronic switches 150 are connected to the aforementioned positive and negative electrical transmission sections to control the charging and discharging of the battery pack 100. Furthermore, the battery pack 100 also includes a heat sink 160 for dissipating heat from the aforementioned electronic switches 150, with a thermal conductivity greater than or equal to 0.5 W / (m·K). In this embodiment, electronic switches 150 are separately installed in the positive and negative electrical transmission sections of the battery pack 100, and a heat sink 160 with a thermal conductivity greater than or equal to 0.5 W / (m·K) is added to the electronic switch 150, thereby enhancing the safety of the power tool battery pack 100 in terms of both power failure protection and heat dissipation.

[0092] In some embodiments, the heat sink 160 may have a one-to-one correspondence with the electronic switch 150, that is, one electronic switch 150 is equipped with one heat sink 160. For example... Figure 6 As shown, in some embodiments, the heat sink 160 and its corresponding electronic switch 150 are respectively disposed on two opposite surfaces of the control circuit board 140. For example, the electronic switch 150 and the heat sink are respectively disposed on the upper and lower surfaces of the board in the figure. Figure 7 As shown, in some embodiments, the heat sink 160 and its corresponding electronic switch 150 are disposed on the same surface of the control circuit board 140, and the heat sink 160 is disposed on the side of the electronic switch 150 away from the board. That is, the electronic switch 150 is between the control circuit board 140 and the heat sink. For example, the electronic switch 150 is disposed on the upper surface of the board in the figure, and the heat sink 160 is disposed above the electronic switch 150. In some embodiments, along the direction perpendicular to the contact surface between the electronic switch 150 and the control circuit board 140, the orthographic projections of the heat sink 160 and its corresponding electronic switch 150 largely coincide to ensure heat dissipation efficiency.

[0093] In some embodiments, the heat sink 160 with a thermal conductivity greater than or equal to 0.5 W / (m·K) may be made of at least one material selected from thermally conductive plastic, thermally conductive metal, and composite thermally conductive material. In some embodiments, the heat sink 160 may use nylon material with thermally conductive filler. In some embodiments, the thermal conductivity of the heat sink 160 may be greater than or equal to 0.8 W / (m·K), and further, the thermal conductivity of the heat sink 160 may be greater than or equal to 1.0 W / (m·K). In some embodiments, the heat sink 160 also has flame retardancy; in some embodiments, the heat sink 160 also has certain tensile strength and flexural strength.

[0094] It should be noted that the various implementation methods and their specific embodiments described above can be combined with each other to comprehensively optimize the safety of the power tool battery pack in this application in terms of power failure protection, thermal management, and other aspects, as well as the accuracy, flexibility and efficiency of related controls, provided that there is no conflict in their characteristics.

[0095] In one alternative implementation, this application refers to... Figure 10The power tool battery pack 100 includes the aforementioned housing 110, battery module 120, and battery terminals 130. A charging electronic switch 152 for controlling the on / off state of the charging circuit 102 is electrically connected between the positive terminal 120a and the positive terminal 131 of the battery module 120, and a discharge electronic switch 151 for controlling the on / off state of the discharge circuit 101 is electrically connected between the negative terminal 120b and the negative terminal 132 of the battery module 120. This embodiment enhances the safety of the battery pack 100, reduces costs compared to related technologies, offers flexible control, and provides good heat dissipation. In some embodiments, the power tool battery pack 100 further includes a controller 141 and a parameter detection module 142. The parameter detection module 142 can detect the electrical parameters of the battery terminals 130 and transmit them to the controller 141. The controller 141 can switch the switching states of the aforementioned discharge electronic switch 151 and / or charging electronic switch 152 based on the currently measured electrical parameters of the battery terminals 130, thereby controlling the on / off state of the discharge circuit 101 and / or charging circuit 102 of the battery pack 100. For example, if the controller 141 determines that there is a risk of overcharging in the battery pack 100 based on the aforementioned electrical parameters, it can control the aforementioned charging electronic switch 152 to be in a closed state, thereby cutting off the charging circuit 102 and realizing overcharge protection. For example, if the controller 141 determines that there is a risk of discharge overcurrent in the battery pack 100 based on the aforementioned electrical parameters, it can control the aforementioned discharge electronic switch 151 to be in a closed state, thereby cutting off the discharge circuit 101 and realizing discharge overcurrent protection. In some embodiments, the aforementioned electrical parameters include, but are not limited to, one or more of the following parameters: voltage, current, resistance / conductance of communication terminal 133; conductance / resistance, capacitance / dielectric constant of positive terminal 131 and / or negative terminal 132; current, voltage, resistance / conductance, capacitance / dielectric constant of detection terminal 134. In some embodiments, the battery pack 100 further includes a temperature sampling module 143, which can at least collect the temperature near the battery terminal 130 and transmit it to the controller 141. The controller 141 will combine the currently measured temperature and electrical parameters to decide how to control the switching state of the aforementioned discharge electronic switch 151 and / or charging electronic switch 152. In some embodiments, if the currently measured electrical parameters of the battery terminal 130 are not within a preset value range, the controller 141 will correspondingly control the discharge electronic switch 151 and / or charging electronic switch 152 to turn off the discharge circuit 101 or charging circuit 102.

[0096] In some embodiments, the aforementioned discharge electronic switch 151 and / or charging electronic switch 152 may be a power electronic switch 150, which may have bidirectional conduction characteristics, capable of controlling the on / off state of its own current loop, and allowing reverse current to pass through when the current reverses. Exemplarily, it(s) may be as follows: Figure 5The power electronic switch 150 with a parasitic diode shown allows the discharge electronic switch 151 to operate without interfering with the function of the charging electronic switch 152 during charging, as its parasitic diode allows a reverse current path. The switching state of the charging electronic switch 152 determines the on / off state of the charging circuit 102. Similarly, during discharging, the charging electronic switch 152, also due to its parasitic diode allowing a reverse current path, does not interfere with the function of the discharge electronic switch 151, and its switching state determines the on / off state of the discharge circuit 101. In some embodiments, the discharge electronic switch 151 and / or the charging electronic switch 152 may also have bidirectional turn-off characteristics. Under normal operating conditions, the discharge electronic switch 151 can be constantly on during charging, and the charging electronic switch 152 can be constantly on during discharging. When it is determined that the discharge circuit 101 or the charging circuit 102 needs to be cut off, turning off at least one of the discharge electronic switch 151 and the charging electronic switch 152 will cut off the discharge circuit 101 or the charging circuit 102. Exemplarily, they can use GaN HEMT bidirectional switches, JFETs, etc. The explanation in this section can be found in the relevant content above.

[0097] In some embodiments, the power tool battery pack 100 includes a control circuit board 140, on which the charging electronic switch 152 and / or discharging electronic switch 151 are disposed. The control circuit board 140 also includes a heat sink 160 corresponding to the electronic switch 150, which dissipates heat from the electronic switch 150. The heat sink 160 has a thermal conductivity greater than or equal to 0.5 W / (m·K). In some embodiments, the electronic switch 150 and the heat sink 160 are arranged in a one-to-one relationship. In some embodiments, the charging electronic switch 152 and / or discharging electronic switch 151 and their heat sink 160 are respectively disposed on two opposite surfaces of the control circuit board 140. In some embodiments, the charging electronic switch 152 and / or discharging electronic switch 151 and their heat sink 160 are disposed on the same surface of the control circuit board 140, with the heat sink 160 positioned opposite to the outside to dissipate heat from the electronic switch 150.

[0098] It should be noted that the various implementation methods and their specific embodiments described above can be combined with each other to comprehensively optimize the safety of the power tool battery pack in this application in terms of power failure protection, thermal management, and other aspects, as well as the accuracy, flexibility and efficiency of related controls, provided that there is no conflict in their characteristics.

[0099] 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, comprising: case; A battery module, housed within the casing, comprises multiple battery cells; The battery terminals include at least a positive terminal, a negative terminal, and a communication terminal, configured to electrically connect the battery pack to an external electrical device; A charging electronic switch is connected between the positive terminal of the battery module and the positive terminal to control the on / off state of the charging circuit; A discharge electronic switch is connected between the negative terminal of the battery module and the negative terminal to control the opening and closing of the discharge circuit.

2. The battery pack according to claim 1, wherein, The charging electronic switch and / or discharging electronic switch are configured as power electronic switches with bidirectional shutdown characteristics.

3. The battery pack according to claim 1, wherein, The charging electronic switch and / or discharging electronic switch are configured as power electronic switches without parasitic diodes.

4. The battery pack according to claim 1, further comprising: A heat sink is configured to dissipate heat from the charging electronic switch and / or the discharging electronic switch, and the thermal conductivity of the heat sink is greater than or equal to 0.5 W / (m·K).

5. The battery pack according to claim 4, wherein, The heat sink and its corresponding charging or discharging electronic switch are respectively disposed on two opposite sides of the control circuit board.

6. The battery pack according to claim 4, wherein, The heat sink and its corresponding charging or discharging electronic switch are disposed on the same surface of the control circuit board, and the heat sink is positioned above the electronic switch.

7. The battery pack according to claim 1, further comprising: The parameter detection module is configured to detect the electrical parameters of the battery terminals; The controller is configured to control the switching state of the charging electronic switch and / or discharging electronic switch based on the electrical parameters.

8. The battery pack according to claim 7, further comprising: The temperature sampling module is configured to collect the temperature at least near the battery terminals; The controller is configured to control the switching state of the charging electronic switch and / or discharging electronic switch in conjunction with the electrical parameters and the temperature.

9. The battery pack according to claim 7, wherein, The electrical parameters include one or more of the following parameters: voltage, current, resistance, and conductance of the communication terminal; capacitance, dielectric constant, conductance, and resistance of the positive and / or negative terminals.

10. The battery pack according to claim 7, wherein, The controller is configured to control the discharge electronic switch and / or charging electronic switch to turn off to cut off the discharge circuit and / or charging circuit when the electrical parameters are not within a preset value range.

11. A battery pack, comprising: case; A battery module, housed within the casing, comprises multiple battery cells; The battery terminals include at least a positive terminal, a negative terminal, and a communication terminal, configured to electrically connect the battery pack to an external electrical device; A charging electronic switch is connected between the negative terminal of the battery module and the negative terminal to control the on / off state of the charging circuit. A discharge electronic switch is connected between the positive terminal of the battery module and the positive terminal to control the opening and closing of the discharge circuit.

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