Battery pack with multi-voltage switching function and voltage switching method

Abstract

The embodiment of the invention relates to the technical field of lithium batteries, and discloses a battery pack with a multi-voltage switching function and a voltage switching method. The method comprises the following steps: acquiring communication data of external equipment, and judging a product type of the external equipment according to the communication data; judging whether to execute output voltage switching operation or not according to the product type; if the type of the external equipment is matched with the current output voltage of the battery pack, the battery pack keeps the output voltage unchanged; if the type of the external equipment is not matched with the current output voltage of the battery pack, the battery pack carries out voltage switching to be matched with the battery pack. The product type of the external equipment is judged through the battery pack, the output voltage is controlled to be switched according to the product type, and a single battery pack can be suitable for various voltage platform tools and chargers.

Description

[Technical field]

[0001] The embodiments of the present invention relate to the technical field of lithium batteries, and in particular to a battery pack with a multi-voltage switching function and a voltage switching method. [Background Technology]

[0002] With the widespread popularity of lithium-ion battery products, the platformization of power tools and chargers is also constantly improving. Currently, there are many voltage platforms that can be used with battery packs with different output voltages.

[0003] Currently, there are many types of voltage platform tools and chargers. Most of the existing battery packs are of a single voltage and can only serve one voltage platform tool. When using multiple power tools, it is necessary to prepare multiple battery packs with different output voltages, which increases the complexity and cost.

[0004] In addition, the products currently on the market simply install two sets of batteries in one housing in order to output dual voltages. Secondly, the voltage selection and replacement of the battery is achieved through the series connection of external plug-ins, and its discharge management is also completed externally. The battery pack cannot automatically switch the voltage mode and select the most suitable voltage output according to the voltage type required by the connected external device, making the battery pack not intelligent enough.

[0005] Therefore, it is necessary to propose a battery pack and a voltage switching method with multi-voltage switching function, which can satisfy that a single battery pack can be applicable to multiple voltage platform tools and chargers without adding additional components, and the battery pack can automatically switch the voltage mode according to the voltage type required by the connected external device, and select the most suitable voltage output, making the battery pack more intelligent. [Summary of the invention]

[0006] The purpose of the embodiments of the present application is to provide a battery pack and a voltage switching method with a multi-voltage switching function, by which the product type of an external device is determined by the battery pack, and the output voltage is switched according to the product type, so that a single battery pack can be applicable to a variety of voltage platform tools and chargers. The battery pack can also automatically switch the voltage mode according to the voltage type required by the connected external device, and select the most suitable voltage output, making the battery pack more intelligent.

[0007] In order to solve the above technical problems, an embodiment of the present application provides a battery pack with a multi-voltage switching function, and the battery pack with a multi-voltage switching function at least includes:

[0008] a first battery pack, the first battery pack being electrically connected to a first control unit that monitors the first battery pack individually;

[0009] a second battery pack, the second battery pack being electrically connected to a second control unit that monitors the second battery pack individually;

[0010] a switching unit, the switching unit being electrically connected to the first battery pack, the second battery pack, the first control unit, and the second control unit;

[0011] Among them, the first control unit includes a first communication unit, and the second control unit includes a second communication unit. The first communication unit and the second communication unit transmit data through a first communication method; the first control unit communicates with an external device through a second communication method and determines the type of the external device. When the type of the external device matches the current output voltage of the battery pack, the battery pack maintains the output voltage unchanged; when the type of the external device does not match the current output voltage of the battery pack, the battery pack performs voltage switching to match the external device.

[0012] In some embodiments of the present application, the first battery pack includes multiple battery cells, and the negative electrode of at least one battery cell among the multiple battery cells is connected to the negative electrode of the battery pack with multi-voltage switching function; the second battery pack includes multiple battery cells, and the positive electrode of at least one battery cell among the multiple battery cells is connected to the positive electrode of the battery pack with multi-voltage switching function.

[0013] In some embodiments of the present application, the switching unit includes multiple switching switches, and the multiple switching switches include at least a first switching switch, a second switching switch and a third switching switch; one end of the first switching switch is connected to the positive electrode of at least one battery cell in the first battery group, and the other end is connected to the positive electrode of at least one battery cell in the second battery group; one end of the second switching switch is connected to the negative electrode of at least one battery cell in the first battery group, and the other end is connected to the negative electrode of at least one battery cell in the second battery group; one end of the third switching switch is connected to the positive electrode of at least one battery cell in the first battery group, and the other end is connected to the negative electrode of at least one battery cell in the second battery group.

[0014] In some embodiments of the present application, the first communication mode includes isolated communication.

[0015] In some embodiments of the present application, the external device includes a charger or a working device using a battery pack.

[0016] In some embodiments of the present application, the battery pack also includes a communication conversion unit, which is connected between the first control unit of the battery pack and the communication port, and is used to convert the data transmission mode between the first control unit and the external device from a two-wire mode to a single-wire mode.

[0017] In some embodiments of the present application, the communication conversion unit also has an abnormal protection function. When any battery pack is abnormal, the first control unit communicates with the external device through the communication conversion unit to inform the external device to shut down.

[0018] The present application also provides a voltage switching method, which is applied to a battery pack with a multi-voltage switching function, and the method includes:

[0019] Acquire communication data of an external device, and determine a product type of the external device according to the communication data;

[0020] Determining whether to perform an output voltage switching operation according to the product type;

[0021] If the type of the external device matches the current output voltage of the battery pack, the battery pack maintains the output voltage unchanged;

[0022] If the type of the external device does not match the current output voltage of the battery pack, the battery pack performs voltage switching to match the external device.

[0023] In some embodiments of the present application, the first output voltage is less than the second output voltage.

[0024] In some embodiments of the present application, the external device includes a charger or a working device using a battery pack. [Drawings]

[0025] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0026] Figure 1 The structural principle of a battery pack with multi-voltage switching function provided by an embodiment of the present application is Figure 1 ;

[0027] Figure 2 The structural principle of a battery pack with multi-voltage switching function provided by an embodiment of the present application is Figure 2 ;

[0028] Figure 3 The structural principle of a battery pack with multi-voltage switching function provided by an embodiment of the present application is Figure 3 ;

[0029] Figure 4 is a schematic diagram of an electronic switch driving circuit provided in an embodiment of the present application;

[0030] Figure 5 This is a flow chart of a voltage switching method for a battery pack with a multi-voltage switching function provided in one embodiment of the present application.

[0031] Among them, 100—battery pack; 101—first battery group; 102—second battery group; 110—first control unit; 120—second control unit; 130—communication conversion unit; 140—switching unit; 111—first communication unit; 121—second communication unit; P+—positive electrode of battery pack; P-—negative electrode of battery pack; D—communication port; 1011, 1012, 1013, 1014, 1015—battery cells of the first battery group; 1021, 1022, 1023, 1024, 1025—battery cells of the second battery group; S1, S2, S3—switching switches. [Specific implementation method]

[0032] To facilitate understanding, some illustrations of concepts related to the embodiments of the present application are given by way of example for reference.

[0033] It should be noted that in this application, "at least one" means one or more, and "more than one" means two or more than two. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The terms "first", "second", "third", "fourth", etc. (if any) in the specification, claims and drawings of this application are used to distinguish similar objects, rather than to describe a specific order or sequence.

[0034] Currently, there are many types of voltage platform tools and chargers. Most of the existing battery packs are of a single voltage and can only serve one voltage platform tool. When using multiple power tools, it is necessary to prepare multiple battery packs with different output voltages, which increases the complexity and cost.

[0035] In order to output dual voltage, the products currently on the market simply install two sets of batteries in one housing. Secondly, the voltage selection and replacement of the battery is achieved through the series connection of external plug-ins, and its discharge management is also completed externally. The battery pack cannot automatically switch the voltage mode and select the most suitable voltage output according to the voltage type required by the connected external device, making the battery pack not intelligent enough.

[0036] In response to the above problems, the present application provides a battery pack with multi-voltage switching function and a voltage switching method.

[0037] Embodiment 1

[0038] This embodiment provides a battery pack with a multi-voltage switching function. Figure 1-Figure 3 The battery pack 100 has a battery pack positive electrode P+, ​​a battery pack negative electrode P- and a communication port D. When the external device and the battery pack 100 are matched and connected, the battery pack positive electrode P+ is connected to the positive terminal of the external device, the battery pack positive electrode P- is connected to the negative terminal of the external device, and the battery pack communication port D is connected to the communication terminal of the external device to realize data transmission.

[0039] The battery pack 100 also has a first battery group 101, a second battery group 102, a first control unit 110, a second control unit 120, a communication conversion unit 130, and a switching unit 140; the first battery group 101 is composed of a plurality of battery cells (1011, 1012, 1013, 1014, 1015), the second battery group 102 is composed of a plurality of battery cells (1021, 1022, 1023, 1024, 1025), the switching unit 140 includes a plurality of switching switches (S1, S2, S3), the first control unit 110 includes a first communication unit 111, and the second control unit 120 includes a second communication unit 121.

[0040] The first battery group 101 is electrically connected to a first control unit 110 that monitors the first battery group 101 individually; the second battery group 102 is electrically connected to a second control unit 120 that monitors the second battery group 102 individually; the switching unit 140 electrically connects the first battery group 101, the second battery group 102, the first control unit 110 and the second control unit 120; wherein the first control unit 110 includes a first communication unit 111, the second control unit 120 includes a second communication unit 121, and the first communication unit 111 and the second communication unit 121 transmit data via a first communication method; the first control unit 110 communicates with an external device via a second communication method and determines the type of the external device, and when the type of the external device matches the current output voltage of the battery pack, the battery pack maintains the output voltage unchanged; when the type of the external device does not match the current output voltage of the battery pack, the battery pack switches from the current output voltage to the target output voltage. That is, the internal control logic of the battery pack is: the first control unit 110 determines whether to control the switching unit to perform a switching action according to the type of the external device. If so, the switching unit 140 is controlled to perform a switching action to switch the output voltage; if not, the switching unit 140 is controlled not to perform a switching action.

[0041] Specifically, the first battery group 101 includes a plurality of battery cells (1011, 1012, 1013, 1014, 1015), the plurality of battery cells are connected in series, and the negative pole of the battery cell 1025 is connected to the negative pole P- of the battery pack with multi-voltage switching function; the second battery group 102 includes a plurality of battery cells (1021, 1022, 1023, 1024, 1025), the plurality of battery cells are connected in series, and the positive pole of the battery cell 1021 is connected to the positive pole P+ of the battery pack with multi-voltage switching function.

[0042] Specifically, the switching unit 140 includes multiple switching switches (S1, S2, S3), one end of the switching switch S3 is connected to the positive electrode of at least one battery cell in the first battery group, and the other end is connected to the positive electrode of at least one battery cell in the second battery group; one end of the switching switch S2 is connected to the negative electrode of at least one battery cell in the first battery group, and the other end is connected to the negative electrode of at least one battery cell in the second battery group; one end of at least one switching switch among the multiple switching switches is connected to the positive electrode of at least one battery cell in the first battery group, and the other end is connected to the negative electrode of at least one battery cell in the second battery group.

[0043] Specifically, each battery cell of the first battery group 101 is connected to the first control unit 110, and the first control unit 110 detects the battery status of each battery cell (1011, 1012, 1013, 1014, 1015). Each battery cell of the second battery group 102 is connected to the second control unit 120, and the second control unit 120 detects the battery status of each battery cell ((1021, 1022, 1023, 1024, 1025), and the battery status includes but is not limited to battery voltage, battery temperature, battery charge status, battery chargeability mark, current, battery fault and other states.

[0044] Specifically, the communication conversion unit 130 is connected between the first control unit 111 of the battery pack 100 and the communication port D, and is used to convert the data transmission mode between the first control unit 111 and the external device from the two-wire mode to the single-wire mode. If two-wire communication is adopted, an electrode will be added, resulting in an increase in cost, while converting from the two-wire mode to the single-wire mode can reduce the production cost of the battery pack without affecting the function. The communication conversion unit 130 serves as a medium for data transmission between the first control unit 111 and the external device. The transmitted data includes but is not limited to: the voltage of a single battery cell of the battery, the temperature of a single battery cell of the battery, the battery voltage, the battery temperature, the number of battery cycles, the battery charge state, the battery rechargeable flag, the charging current, the battery type (series-parallel information, manufacturer information), fault history data, etc.

[0045] In this embodiment, when the battery pack 100 is not connected to an external device, the battery pack remains in the first output voltage mode.

[0046] When the battery pack 100 is connected to an external device, the battery pack maintains the first output voltage to power the external device. The first control unit 111 communicates with the external device through the communication port D and receives the communication data transmitted by the external device. The first control unit 111 determines the type of the external device according to the above communication data. If the type of the external device currently connected to the battery pack matches the first output voltage output by the battery pack, the battery pack maintains the current output voltage unchanged; if the type of the external device currently connected to the battery pack does not match the first output voltage output by the battery pack, the battery pack switches the output voltage from the first output voltage to the second output voltage. That is, the internal control logic of the battery pack is: the first control unit 111 determines whether the external device requires a single voltage or a dual voltage; if the external device requires a single voltage, that is, the battery pack 100 needs to output the first output voltage to power the external device, the first control unit 111 controls the switching unit 140 not to act, and the output voltage remains unchanged; if the external device requires a dual voltage, that is, the battery pack 100 needs to output the second output voltage to power the external device, the first control unit 111 controls the switching unit 140 to act, and the output voltage switches from the first output voltage to the second output voltage. The second output voltage is greater than the first output voltage. In a preferred embodiment, the second output voltage is an integer multiple of the first output voltage, such as two times, three times, four times, etc.

[0047] Specifically, when the battery pack 100 is not connected to an external device, the switch S1 is opened, the switch S2 is closed, the switch S3 is closed, the first battery group 110 and the second battery group 111 are connected in parallel, and the battery pack is in the first output voltage mode.

[0048] When the battery pack 100 is connected to an external device, in the initial connection state, the battery pack maintains the first output voltage mode, the switch S1 is disconnected, the switch S2 is closed, and the switch S3 is closed, and the first battery group 110 and the second battery group 111 are in a parallel state. The first control unit 111 is activated because the battery pack is powered on, and the first control unit 111 communicates with the external device via the communication conversion unit 130 and the communication port D to obtain the communication data transmitted by the external device. The first control unit 111 determines the type of the external device according to the above communication data, that is, determines whether the external device requires a single voltage or a dual voltage; if the external device requires a single voltage, the output voltage of the battery pack is kept unchanged, the switch S1 is kept disconnected, the switch S2 is closed, and the switch S3 is closed; if the external device requires a dual voltage, the conduction state of the switch is changed, the switch S1 is controlled to be closed, the switch S2 is disconnected, and the switch S3 is disconnected, so that the first battery group 110 and the second battery group 111 are in a series state, that is, the output voltage switching action of the battery pack is realized, and the output voltage is switched from the first output voltage to the second output voltage.

[0049] In this embodiment, the communication conversion unit 130 also has an abnormality protection function. When any battery pack is abnormal, the first control unit communicates with the external device through the communication conversion unit to inform the external device to shut down.

[0050] Specifically, when the battery pack 110 operates in the first output voltage mode, the first control unit 110 detects the battery status of each of the battery cells (1011, 1012, 1013, 1014, 1015). When any of the above battery cells fails, the failure state includes but is not limited to over-temperature and over-voltage state. The first control unit communicates with the external device through the communication conversion unit to inform the external device to shut down. The second control unit 120 detects the battery status of each of the battery cells ((1021, 1022, 1023, 1024, 1025). When any of the above battery cells fails, the The fault state includes but is not limited to over-temperature and over-voltage states. The second control unit 120 communicates with the first communication unit 111 in an isolated communication manner through the second communication unit 121. The second control unit 120 informs the first control unit 110 that the second battery pack 102 has a fault. The first control unit 110 receives the fault information notified by the second control unit 120 and notifies the external device of the fault information in a second communication manner, notifying the external device of the fault information, and the external device shuts down to achieve abnormal protection. The first control unit 110 sends a fault signal to the external device through the communication port D, including but not limited to sending high and low level signals and square wave signals.

[0051] The second communication method is different from the first communication method. The first communication method includes but is not limited to isolated communication. Isolated communication refers to a method in which DC and AC between different parts of a communication system are blocked by isolation technology while allowing signals and power to be transmitted between these parts. This technology is very important in many applications, such as using gate drivers on the high side of power supplies or motor drive circuits, protecting low-voltage circuits in high-voltage systems, communicating separately between systems with different voltage potentials, or preventing electric shock caused by the final product in high-voltage applications.

[0052] The application scenarios of isolated communication include but are not limited to: when the external nodes of the 485 communication interface are connected to high voltage, isolation can protect the back-end circuit from damage and avoid the risk of electric shock; when the 485 communication nodes are far apart and there is a voltage difference between the two ends of the earth, isolation can prevent the ground potential from affecting communication in the form of common mode voltage and avoid damage to the back-end circuit; between 485 communication nodes that are far apart, isolation can disconnect the ground loop and prevent the ground loop current from causing circuit system failure.

[0053] The technical solutions to achieve isolated communication include:

[0054] (1) Optocoupler isolation: The signal is isolated and transmitted through an optocoupler, which is a traditional isolation solution.

[0055] (2) Digital isolation: Using digital isolators, the encoding and decoding electronics are made using standard packaging and IC processes, supporting higher speeds and lower power consumption.

[0056] (3) Daisy chain communication solution: Communication isolation between high and low voltage is achieved through transformers or capacitors. The AFE on the high voltage side is powered entirely by the battery side, and no additional power supply is required.

[0057] (4) Both sides of the high and low voltage isolation are powered by themselves: When using digital isolation chips for communication, both sides of the isolation chip need to be powered. The high voltage side is powered by the battery through voltage conversion, and the low voltage side is powered by the low voltage.

[0058] Therefore, isolated communication is used to protect the communication system from high voltage and noise, ensuring the stability and security of communication. Through different isolation schemes, safe communication between systems with different voltage potentials can be achieved.

[0059] The second communication method includes but is not limited to UART protocol communication. Universal Asynchronous Receiver / Transmitter (Universal Asynchronous Receiver / Transmitter), commonly known as UART, is an asynchronous receiver / transmitter. It converts the data to be transmitted between serial communication and parallel communication. As a type of asynchronous serial communication protocol, UART works by transmitting each character of the transmitted data one by one.

[0060] When the battery pack 110 operates in the second output voltage mode, the first control unit 110 detects the battery status of each of the battery cells (1011, 1012, 1013, 1014, 1015). When any of the above battery cells is in a fault state, the fault state includes but is not limited to over-temperature and over-voltage state, the first control unit communicates with the external device through the communication conversion unit to inform the external device to shut down; the second control unit 120 detects the battery status of each of the battery cells ((1021, 1022, 1023, 1024, 1025). When any of the above battery cells is in a fault state, the fault The state includes but is not limited to over-temperature and over-voltage state. The second control unit 120 communicates with the first communication unit 111 in an isolated communication manner through the second communication unit 121. The second control unit 120 informs the first control unit 110 that the second battery pack 102 has a fault. The first control unit 110 receives the fault information informed by the second control unit 120 and informs the external device of the fault information in a second communication manner, informs the external device of the fault information, and the external device shuts down to achieve abnormal protection. The first control unit 110 sends a fault signal to the external device through the communication port D, including but not limited to sending high and low level signals and square wave signals.

[0061] In one implementation of this embodiment, the switching switch may be an electronic switch, as long as the switching switch can realize the switching of the circuit. In an optional embodiment, the electronic switch includes but is not limited to MOS (Metal-Oxide-Semiconductor Field-Effect Transistor, MOSFET), relay, reference Figure 2 In one embodiment shown, the switch is MOS. In a circuit where MOS is used as a switch, a parasitic body diode exists in the manufacturing process of MOS. The body diode has a unidirectional conduction function. Therefore, it is easy for a small amount of current to flow when MOS is in a non-conducting state. This phenomenon can cause the battery pack to charge each other, resulting in an unbalanced battery pack. Therefore, a pair of MOS tubes are required to be connected in series to realize the switch function. In this embodiment, each switch uses a group of back-to-back MOS, which is controlled by the driving circuit unit.

[0062] Specific reference Figure 4 The schematic diagram of the electronic switch driving circuit is shown. As shown in the figure, one of the pins of the first control unit is connected to the DCDC power module, and two of the pins of the first control unit are connected to the optocoupler 1 and the optocoupler 2 respectively, and the other ends of the optocoupler 1 and the optocoupler 2 are connected to a pair of back-to-back MOS via the gate driver; the DCDC power module is connected to the first control unit, the optocoupler 1 and the optocoupler 2 respectively, and the DCDC power module supplies power to the first control unit, the optocoupler 1 and the optocoupler 2; the isolated power supply is connected to the optocoupler 1 and the optocoupler 2 respectively, and the isolated power supply supplies power to the optocoupler 1 and the optocoupler 2. When the battery pack is powered on, the first control unit, the optocoupler 1, the optocoupler 2, and the gate driver draw power from the isolated power supply and the DCDC power module, and the first control unit outputs a first control signal to the optocoupler 1 and the optocoupler 2 to control the conduction and shutdown of the optocoupler 1 and the optocoupler 2; when the optocoupler 1 and the optocoupler 2 are turned on, the current passes through the gate driver to speed up the control of the conduction of the back-to-back MOS, so that the first control unit can control the MOS more quickly.

[0063] In another implementation of this embodiment, the switching switch may be a mechanical switch, as long as the switch can achieve the switching of the circuit. In an optional embodiment, refer to Figure 3 In one embodiment shown, the switching switch is a double-pole double-throw switch. In other alternative embodiments, the switching switch may be a normally open switch; for example: when the battery pack is not connected to an external device, that is, a working device or charger using the battery pack, the normally open switch is in S1 disconnected, S2 and S3 are in closed state, and the battery pack works in the first output voltage mode. When a working device or charger using the battery pack is connected, the special dual-voltage slide rail structure automatically changes the switch state, so that S1 is closed, S2 and S3 are disconnected, and the battery pack is in the second output voltage mode; when the working device or charger using the battery pack is removed, the special dual-voltage slide rail structure automatically changes the switch state, so that S1 is disconnected, S2 and S3 are closed, and the battery pack works in the first output voltage mode.

[0064] In another implementation of this embodiment, when the external device is a charger, in the initial connection state, the battery pack maintains the first voltage mode, the switch S1 is disconnected, the switch S2 is closed, the switch S3 is closed, and the first battery pack 110 and the second battery pack 111 are in a parallel state. The first control unit 111 is activated because the battery pack is powered on, and the first control unit 111 communicates with the external device via the communication conversion unit 130 and the communication port D to obtain the communication data transmitted by the external device. The first control unit 111 determines the type of the external device according to the above communication data, that is, determines whether the external device is a single voltage platform charger or a dual voltage platform charger; if the external device is a single voltage platform charger, the switch of the battery pack is kept unchanged, the switch S1 is kept disconnected, the switch S2 is closed, and the switch S3 is closed; if the external device is a dual voltage platform charger, the conduction state of the switch is changed to match the external device, the switch S1 is controlled to be closed, the switch S2 is disconnected, and the switch S3 is disconnected, so that the first battery pack 110 and the second battery pack 111 are in a series state, and the battery pack starts to charge.

[0065] Embodiment 2

[0066] refer to Figure 4 This embodiment provides a voltage switching method, which is applied to a battery pack with a multi-voltage switching function. The method is implemented based on all circuits of the battery pack with a multi-voltage switching function described in the above embodiment, and the method includes:

[0067] Acquire communication data of an external device, and determine a product type of the external device according to the communication data;

[0068] Determining whether to perform an output voltage switching operation according to the product type;

[0069] If the type of the external device matches the current output voltage of the battery pack, the battery pack maintains the output voltage unchanged;

[0070] If the type of the external device does not match the current output voltage of the battery pack, the battery pack performs voltage switching to match the external device.

[0071] Specifically, the first output voltage is less than the second output voltage. In a preferred embodiment, the second output voltage is an integer multiple of the first output voltage, such as two, three, four times, etc. The external device includes a charger or a working device using a battery pack.

[0072] Specifically, the first control unit 110 communicates with the external device through the second communication method and determines the type of the external device. When the type of the external device matches the current output voltage of the battery pack, the battery pack maintains the output voltage unchanged; when the type of the external device does not match the current output voltage of the battery pack, the battery pack switches the voltage to match the external device. That is, the internal control logic of the battery pack is: the first control unit 110 determines whether to control the switching unit to perform a switching action according to the type of the external device. If so, the switching unit 140 is controlled to perform a switching action to switch the output voltage; if not, the switching unit 140 is controlled not to perform a switching action.

[0073] In this embodiment, when the battery pack 100 is not connected to an external device, the battery pack remains in the first output voltage mode.

[0074] When the battery pack 100 is connected to an external device, the battery pack maintains the first output voltage to power the external device. The first control unit 111 communicates with the external device through the communication port D and receives the communication data transmitted by the external device. The first control unit 111 determines the type of the external device according to the above communication data. If the type of the external device currently connected to the battery pack matches the first output voltage output by the battery pack, the battery pack maintains the current output voltage unchanged; if the type of the external device currently connected to the battery pack does not match the first output voltage output by the battery pack, the battery pack switches the output voltage from the first output voltage to the second output voltage. That is, the internal control logic of the battery pack is: the first control unit 111 determines whether the external device requires a single voltage or a dual voltage; if the external device requires a single voltage, that is, the battery pack 100 needs to output the first output voltage to power the external device, the first control unit 111 controls the switching unit 140 not to act, and the output voltage remains unchanged; if the external device requires a dual voltage, that is, the battery pack 100 needs to output the second output voltage to power the external device, the first control unit 111 controls the switching unit 140 to act, and the output voltage switches from the first output voltage to the second output voltage. The second output voltage is greater than the first output voltage. In a preferred embodiment, the second output voltage is an integer multiple of the first output voltage, such as two times, three times, or four times.

[0075] Specifically, when the battery pack 100 is not connected to an external device, the switch S1 is opened, the switch S2 is closed, the switch S3 is closed, the first battery group 110 and the second battery group 111 are connected in parallel, and the battery pack is in the first output voltage mode.

[0076] When the battery pack 100 is connected to an external device, in the initial connection state, the battery pack maintains the first output voltage mode, the switch S1 is disconnected, the switch S2 is closed, and the switch S3 is closed, and the first battery group 110 and the second battery group 111 are in a parallel state. The first control unit 111 is activated because the battery pack is powered on, and the first control unit 111 communicates with the external device via the communication conversion unit 130 and the communication port D to obtain the communication data transmitted by the external device. The first control unit 111 determines the type of the external device according to the above communication data, that is, determines whether the external device requires a single voltage or a dual voltage; if the external device requires a single voltage, the output voltage of the battery pack is kept unchanged, the switch S1 is kept disconnected, the switch S2 is closed, and the switch S3 is closed; if the external device requires a dual voltage, the conduction state of the switch is changed, the switch S1 is controlled to be closed, the switch S2 is disconnected, and the switch S3 is disconnected, so that the first battery group 110 and the second battery group 111 are in a series state, that is, the output voltage switching action of the battery pack is realized, and the output voltage is switched from the first output voltage to the second output voltage.

[0077] In one implementation of this embodiment, the switching switch may be an electronic switch, as long as the switching switch can realize the switching of the circuit. In an optional embodiment, the electronic switch includes but is not limited to MOS (Metal-Oxide-Semiconductor Field-Effect Transistor, MOSFET), relay, reference Figure 2 In one embodiment shown, the switch is MOS. In a circuit where MOS is used as a switch, a parasitic body diode exists in the manufacturing process of MOS. The body diode has a unidirectional conduction function. Therefore, it is easy for a small amount of current to flow when MOS is in a non-conducting state. This phenomenon can cause the battery pack to charge each other, resulting in an unbalanced battery pack. Therefore, a pair of MOS tubes are required to be connected in series to realize the switch function. In this embodiment, each switch uses a group of back-to-back MOS, which is controlled by the driving circuit unit.

[0078] In another implementation of this embodiment, the switching switch may be a mechanical switch, as long as the switching switch can realize the switching of the circuit. In an optional embodiment, refer to Figure 3In one embodiment shown, the switching switch is a double-pole double-throw switch. In other alternative embodiments, the switching switch may be a normally open switch; for example: when the battery pack is not connected to an external device, that is, a working device or charger using the battery pack, the normally open switch is in S1 disconnected, S2 and S3 are in closed state, and the battery pack works in the first output voltage mode. When a working device or charger using the battery pack is connected, the special dual-voltage slide rail structure automatically changes the switch state, so that S1 is closed, S2 and S3 are disconnected, and the battery pack is in the second output voltage mode; when the working device or charger using the battery pack is removed, the special dual-voltage slide rail structure automatically changes the switch state, so that S1 is disconnected, S2 and S3 are closed, and the battery pack works in the first output voltage mode.

[0079] In another implementation of this embodiment, when the external device is a charger, in the initial connection state, the battery pack maintains the first voltage mode, the switch S1 is disconnected, the switch S2 is closed, the switch S3 is closed, and the first battery pack 110 and the second battery pack 111 are in a parallel state. The first control unit 111 is activated because the battery pack is powered on, and the first control unit 111 communicates with the external device via the communication conversion unit 130 and the communication port D to obtain the communication data transmitted by the external device. The first control unit 111 determines the type of the external device according to the above communication data, that is, determines whether the external device is a single voltage platform charger or a dual voltage platform charger; if the external device is a single voltage platform charger, the switch of the battery pack is kept unchanged, the switch S1 is kept disconnected, the switch S2 is closed, and the switch S3 is closed; if the external device is a dual voltage platform charger, the conduction state of the switch is changed to match the external device, the switch S1 is controlled to be closed, the switch S2 is disconnected, and the switch S3 is disconnected, so that the first battery pack 110 and the second battery pack 111 are in a series state, and the battery pack starts to charge.

[0080] That is, those skilled in the art can understand that all or part of the steps in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a program, and the program is stored in a storage medium, including several instructions to enable a device (which can be a single-chip microcomputer, chip, etc.) or a processor to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0081] Those skilled in the art will appreciate that the above embodiments are specific embodiments for implementing the present invention, and that in actual applications, various changes may be made in form and detail without departing from the spirit and scope of the present invention.

Claims

1. A battery pack with multi-voltage switching function, characterized in that: The battery pack with multi-voltage switching function comprises at least: a first battery pack, the first battery pack being electrically connected to a first control unit that monitors the first battery pack individually; a second battery pack, the second battery pack being electrically connected to a second control unit that monitors the second battery pack individually; a switching unit, the switching unit being electrically connected to the first battery pack, the second battery pack, the first control unit, and the second control unit; Among them, the first control unit includes a first communication unit, and the second control unit includes a second communication unit. The first communication unit and the second communication unit transmit data through a first communication method; the first control unit communicates with an external device through a second communication method and determines the type of the external device. When the type of the external device matches the current output voltage of the battery pack, the battery pack maintains the output voltage unchanged; when the type of the external device does not match the current output voltage of the battery pack, the battery pack performs voltage switching to match the external device.

2. The battery pack with multi-voltage switching function according to claim 1, characterized in that: The first battery pack includes multiple battery cells, and the negative electrode of at least one of the multiple battery cells is connected to the negative electrode of the battery pack with multi-voltage switching function; the second battery pack includes multiple battery cells, and the positive electrode of at least one of the multiple battery cells is connected to the positive electrode of the battery pack with multi-voltage switching function.

3. The battery pack with multi-voltage switching function according to claim 2, characterized in that: The switching unit includes multiple switching switches, and the multiple switching switches include at least a first switching switch, a second switching switch and a third switching switch; one end of the first switching switch is connected to the positive electrode of at least one battery cell in the first battery group, and the other end is connected to the positive electrode of at least one battery cell in the second battery group; one end of the second switching switch is connected to the negative electrode of at least one battery cell in the first battery group, and the other end is connected to the negative electrode of at least one battery cell in the second battery group; one end of the third switching switch is connected to the positive electrode of at least one battery cell in the first battery group, and the other end is connected to the negative electrode of at least one battery cell in the second battery group.

4. The battery pack with multi-voltage switching function according to claim 1, characterized in that: The first communication mode includes isolated communication.

5. The battery pack with multi-voltage switching function according to claim 1, characterized in that: The external device includes a charger or a working device using a battery pack.

6. The battery pack with multi-voltage switching function according to claim 1, characterized in that: The battery pack further includes a communication conversion unit, which is connected between the first control unit of the battery pack and a communication port and is used to convert a data transmission mode between the first control unit and an external device from a two-line mode to a single-line mode.

7. The battery pack with multi-voltage switching function according to claim 6, characterized in that: The communication conversion unit also has an abnormal protection function. When any battery pack is abnormal, the first control unit communicates with the external device through the communication conversion unit to inform the external device to shut down.

8. A voltage switching method, the method being applied to a battery pack having a multi-voltage switching function, characterized in that: The method comprises: Acquire communication data of an external device, and determine a product type of the external device according to the communication data; Determining whether to perform an output voltage switching operation according to the product type; If the type of the external device matches the current output voltage of the battery pack, the battery pack maintains the output voltage unchanged; If the type of the external device does not match the current output voltage of the battery pack, the battery pack voltage is switched to match the external device.

9. The voltage switching method according to claim 8, characterized in that: The first output voltage is lower than the second output voltage.

10. The voltage switching method according to claim 8, characterized in that: The external device includes a charger or a working device using a battery pack.

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