Battery pack charging and discharging circuit and electric device

Abstract

The utility model belongs to BMS relevant technical field especially, it is more particularly to a kind of battery pack charging and discharging circuit and electrical equipment.Through being set in main control circuit in circuit, setting state monitoring circuit, cooperate vehicle-mounted circuit and charging circuit, to make battery pack wake up after pull-up power supply end keeps power supply, to make first wake-up end and state monitoring end keep high voltage;Switching circuit is used to make first wake-up end detect falling edge signal, to wake up battery pack and control discharge control end to open discharge;Load circuit is used to make state monitoring end monitor voltage change when charging circuit is incorporated, and control charging control end to open charging.Through the charging and discharging switching of state monitoring circuit to circuit, to make the versatility of circuit higher, more convenient battery pack incorporation and disassembly, and the battery pack incorporation of this mode does not need to carry out software logic and hardware change, and the circuit structure.

Description

Technical Field

[0001] This utility model belongs to the field of BMS related technology, and in particular relates to a battery pack charging and discharging circuit and electrical equipment. Background Technology

[0002] As lithium-ion batteries are increasingly used in two-wheeled vehicles, power tools, small household appliances and other fields, the requirements for battery life are also increasing. Therefore, it is necessary to design lithium-ion battery packs to achieve higher battery life requirements.

[0003] In existing technologies, the circuitry for multi-battery packs is often quite complex, and each battery pack requires additional control circuitry. This results in a complex control circuit structure for the entire multi-battery pack, making software control difficult. Furthermore, when merging battery packs with complex logic and structure, adjustments to both software and hardware are required, which hinders rapid disassembly. In some low-cost applications, such as two-wheeled vehicles, the highly complex circuit structure with its complex structure and software logic is not conducive to low-cost production and practical applications. Utility Model Content

[0004] To address the aforementioned problems, this invention proposes a battery pack charging and discharging circuit and related electrical equipment. By incorporating a status monitoring circuit, in conjunction with the vehicle's onboard circuitry and the charger's charging circuit, and through a switching circuit and a load circuit, the voltage changes in the status monitoring circuit are monitored. This allows the battery pack to switch charging and discharging modes based on the status monitoring circuit. Furthermore, when other battery packs of different specifications are integrated, the same circuit can be used to achieve automatic switching between charging and discharging modes without altering the control logic. Moreover, abnormalities between battery packs will not affect each other's operational status.

[0005] In a first aspect, this utility model proposes a battery pack charging and discharging circuit, comprising: The main control circuit includes a charging control terminal, a discharging control terminal, a first wake-up terminal, and a status monitoring terminal; the charging control terminal is used to control the charging of the battery pack, and the discharging control terminal is used to control the discharging of the battery pack. The status monitoring circuit is equipped with a pull-up power supply terminal, a status input terminal, and a status output terminal; the pull-up power supply terminal is connected to the main control circuit; the status output terminal is connected to the first wake-up terminal and the status monitoring terminal. The vehicle-mounted circuit includes a first signal output terminal, a positive terminal of the charging and discharging circuit, and a negative terminal of the charging and discharging circuit; a switching circuit is provided between the first signal output terminal and the negative terminal of the charging and discharging circuit. The charging circuit is provided with a second signal output terminal; a load circuit is provided between the second signal output terminal and the negative terminal of the charging circuit. The first signal output terminal and the second signal output terminal are connected to the status input terminal; after the battery pack is woken up, the pull-up power supply terminal maintains power supply so that the first wake-up terminal and the status monitoring terminal maintain a high voltage; the switching circuit is used to enable the first wake-up terminal to detect the falling edge signal, thereby waking up the battery pack and controlling the discharge control terminal to start discharging; the load circuit is used to enable the status monitoring terminal to detect the voltage change when the charging circuit is connected and control the charging control terminal to start charging.

[0006] By incorporating a status monitoring circuit within the main control circuit, in conjunction with the vehicle-mounted circuit and charging circuit, the power supply terminal of the battery pack is kept powered after wake-up, ensuring a high voltage at both the first wake-up terminal and the status monitoring terminal. A switching circuit enables the first wake-up terminal to detect a falling edge signal, thereby waking up the battery pack and controlling the discharge control terminal to initiate discharge. A load circuit allows the status monitoring terminal to detect voltage changes when the charging circuit is connected and controls the charging control terminal to start charging. The status monitoring circuit enables charging and discharging switching, resulting in greater circuit versatility and easier integration and removal of battery packs. This method of battery pack integration requires no changes to software logic or hardware, and the circuit structure is simple, ensuring that the operating states of different battery packs do not interfere with each other.

[0007] In some implementations, the main control circuit includes a first chip and a second chip. The charging control terminal and the discharging control terminal are located on the first chip, and the first wake-up terminal and the status detection terminal are located on the second chip. The status output terminal is connected to the second chip, and the pull-up power supply terminal is connected to the first chip. The first chip has a power output terminal, and the second chip has a power input terminal. The power output terminal is connected to the power input terminal so that when the battery pack is woken up, the first chip supplies power to the second chip and supplies power to the pull-up power supply terminal to realize the battery pack wake-up.

[0008] In some embodiments, the main control circuit further includes a first MOSFET, a second MOSFET, a first resistor, a second resistor, a third resistor, and a fourth resistor; the first and second resistors are connected in series and disposed between the positive terminal of the battery pack and the charging control terminal; the gate of the first MOSFET is connected between the first and second resistors, and the source of the first MOSFET is connected to the positive terminal of the battery pack; the third and fourth resistors are connected in series and disposed between the positive terminal of the charging / discharging circuit and the discharging control terminal; the gate of the second MOSFET is connected between the third and fourth resistors, and the source of the second MOSFET is connected to the positive terminal of the charging / discharging circuit; the drain of the first MOSFET and the drain of the second MOSFET are connected.

[0009] In some implementations, the condition monitoring circuit includes a fifth resistor, a sixth resistor, and a first diode; One end of the fifth resistor is connected to the pull-up power supply terminal, and the other end of the fifth resistor is connected to the anode of the first diode and one end of the sixth resistor; the other end of the sixth resistor is the status output terminal and is connected to the first wake-up terminal and the status monitoring terminal; the cathode of the first diode is the status input terminal.

[0010] In some embodiments, a wake-up circuit is also included. The wake-up circuit is provided with a second wake-up terminal and a wake-up input terminal. The second wake-up terminal is connected to the first chip, and the wake-up input terminal is connected to the positive terminal of the charging and discharging circuit, so as to wake up the battery pack through the wake-up circuit.

[0011] In some implementations, the wake-up circuit includes a seventh resistor, a Zener diode, an eighth resistor, a first capacitor, a second diode, and a ninth resistor; One end of the seventh resistor is the wake-up input terminal, and the other end of the seventh resistor is connected to the cathode of the Zener diode; the anode of the Zener diode is connected to one end of the eighth resistor and the first capacitor, the other end of the eighth resistor and the first capacitor is connected to the anode of the second diode, the cathode of the second diode is connected to one end of the ninth resistor, and the other end of the ninth resistor is the second wake-up terminal.

[0012] In some embodiments, a communication circuit is also included, which includes a third chip, a third diode, and an eleventh resistor; the third chip includes a first input terminal, a second input terminal, a communication output terminal, and a ground terminal; the third diode is connected between the first input terminal and the second input terminal, the eleventh resistor is disposed on the first input terminal, and the communication output terminal is connected to the second chip.

[0013] In some implementations, the load circuit includes a tenth resistor, which is disposed between the second signal output terminal and the negative terminal of the charging circuit.

[0014] In some implementations, the switching circuit includes a switch to turn the first signal output terminal and the negative terminal of the charging / discharging circuit on and off.

[0015] Secondly, this utility model also proposes an electrical device, including a battery pack charging and discharging circuit as proposed in the first aspect, at least two battery packs, a charger, and an electrical device body; the status input terminals of all battery packs are connected together, and the positive terminals of all battery packs are connected to the positive terminal of the charging and discharging circuit, and the negative terminals of all battery packs are connected to the negative terminal of the charging and discharging circuit. The battery pack charging and discharging circuit is set between each battery pack, charger, and the main body of the electrical device to enable the battery pack to switch between charging and discharging. A voltage equalization module is set between the battery packs to ensure that the high-voltage battery pack is discharged first.

[0016] The beneficial effects of the battery pack charging and discharging circuit and electrical equipment of this utility model are: By incorporating a status monitoring circuit within the main control circuit, in conjunction with the vehicle-mounted circuit and charging circuit, the power supply terminal of the battery pack is kept powered after wake-up, ensuring a high voltage at both the first wake-up terminal and the status monitoring terminal. A switching circuit is used to detect a falling edge signal at the first wake-up terminal, thereby waking up the battery pack and controlling the discharge control terminal to start discharging. A load circuit is used to detect voltage changes at the status monitoring terminal when the charging circuit is connected, and to control the charging control terminal to start charging. The status monitoring circuit enables charging and discharging switching, resulting in greater circuit versatility and easier integration and removal of the battery pack. Furthermore, this method of battery pack integration requires no changes to software logic or hardware, and the circuit structure is simple. Attached Figure Description

[0017] Figure 1 This is a framework diagram of a battery pack charging and discharging circuit according to the present invention. Figure 2 This is a circuit diagram of a battery pack charging and discharging circuit according to the present invention. Figure 3 This is a frame diagram of an electrical device according to the present invention. Detailed Implementation

[0018] The preferred embodiments of this application will now be described in detail with reference to the accompanying drawings, so that the advantages and features of this application can be more easily understood by those skilled in the art, thereby providing a clearer definition of the scope of protection of this application.

[0019] Please refer to the diagrams, where the same component symbols represent the same components. The principles of this application are illustrated by way of example implementation in a suitable computing environment. The following description is based on the specific embodiments of this application exemplified, and should not be construed as limiting other specific embodiments not detailed herein.

[0020] As used herein, the term "module" can refer to a software or hardware object that executes on the computing system. The various components, modules, engines, and services described herein can be implementations on the computing system. The apparatuses and methods described herein can be implemented in software or hardware, both of which are within the scope of this application.

[0021] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0022] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0023] Example 1: like Figure 1 As shown, this utility model proposes a battery pack charging and discharging circuit, including: The main control circuit 1 is equipped with a charging control terminal U1_47, a discharging control terminal U1_44, a first wake-up terminal U2_40, and a status monitoring terminal U2_17; the charging control terminal U1_47 is used to control the charging of the battery pack, and the discharging control terminal U1_44 is used to control the discharging of the battery pack. The status monitoring circuit 2 is equipped with a pull-up power supply terminal U1_37, a status input terminal VLOCK, and a status output terminal; the pull-up power supply terminal U1_37 is connected to the main control circuit 1; the status output terminal is connected to the first wake-up terminal U2_40 and the status monitoring terminal U2_17; The vehicle circuit 3 is provided with a first signal output terminal VLOCK1, a positive terminal P+ / C+ of the charging and discharging circuit, and a negative terminal P- / C- of the charging and discharging circuit; a switching circuit 31 is provided between the first signal output terminal VLOCK1 and the negative terminal P- / C- of the charging and discharging circuit. The charging circuit 4 is provided with a second signal output terminal VLOCK2; a load circuit 41 is provided between the second signal output terminal VLOCK2 and the negative terminal of the charging circuit 4. Among them, the first signal output terminal VLOCK1 and the second signal output terminal VLOCK2 are connected to the status input terminal VLOCK; after the battery pack is woken up, the pull-up power supply terminal U1_37 keeps the power supply, so that the first wake-up terminal U2_40 and the status monitoring terminal U2_17 keep the voltage high; the switching circuit 31 is used to enable the first wake-up terminal U2_40 to detect the falling edge signal, thereby waking up the battery pack and controlling the discharge control terminal U1_44 to start discharging; the load circuit 41 is used to enable the status monitoring terminal U2_17 to detect the voltage change when the charging circuit 4 is connected, and control the charging control terminal U1_47 to start charging.

[0024] Specifically, a main control circuit 1 is set up to control the charging and discharging of the battery pack. The charging control terminal U1_47 controls the power supply, more specifically, the charger charges the battery pack. The discharging control terminal U1_44 controls the battery pack to charge the electrical devices, more specifically, the entire vehicle. After the battery pack is woken up, voltage changes are detected by the first wake-up terminal U2_40 and the status monitoring terminal U2_17, respectively. The first wake-up terminal U2_40 mainly determines whether the battery pack has switched from charging mode to discharging mode or from sleep mode to discharging mode by detecting the falling edge. The principle is that after the battery pack is woken up, the power supply terminal U1_37 is pulled up to maintain a high voltage on both the first wake-up terminal U2_40 and the status monitoring terminal U2_17. Meanwhile, the vehicle circuit 3, through the switching circuit 31, ensures that when the circuit is turned on, the voltage at the first signal output terminal VLOCK1 is pulled low by the negative terminal P- / C- of the charging and discharging circuit, resulting in a falling edge signal. After detecting this falling edge signal, the main control circuit 1 opens the discharging control terminal U1_44 to discharge. In some more specific embodiments, the on-board circuit 3 is integrated into the vehicle interior, or it can be a separate external circuit to enable manual discharge on / off settings or provide additional judgment logic to control discharge. It is understood that the first wake-up terminal U2_40 needs to be implemented through the digital port of the main control circuit 1; for example, when a change from 1 to 0 is detected, it determines that the battery pack is entering an external discharge mode.

[0025] The status monitoring terminal U2_17 can monitor the voltage changes of the status monitoring circuit 2. When the voltage value enters a certain range, it can be determined that the charging mode has been entered. This is achieved by reducing the pulled-up voltage to a certain range through the load circuit 41 of the charging circuit 4, thereby realizing the voltage change at the status monitoring terminal, and then controlling the charging control terminal U1_47 of the main control circuit 1 to control the charging of the battery pack. In some more specific embodiments, the charging circuit 4 is located at the charging port of the charger, or it can be located in an external circuit outside the control circuit of the charger. It is only necessary to connect the status input terminal VLOCK and the second signal output terminal VLOCK2 when the charger is plugged in. It is understood that the status monitoring terminal needs to be located at the analog signal port of the main control circuit 1 to realize the monitoring of the voltage value.

[0026] It should be noted that the above method requires the first wake-up terminal U2_40 and the status monitoring terminal U2_17 to periodically scan the voltage, and the period interval can be set to 0.3mm. Meanwhile, to avoid misjudging the falling edge due to voltage division when the charger is plugged in, the main control circuit 1 usually needs to be turned on for a period of time before switching from charging to discharging. When switching from charging to discharging, combined with the voltage value judged by the status monitoring terminal U2_17, this embodiment provides a more specific implementation of the control method of the above circuit. The pull-up power supply terminal U1_37 is usually 3.3V. If the voltage detected by the status monitoring terminal U2_17 during charging is 1.2V-2.8V, and after the switch circuit 31 is turned on, the status monitoring circuit 2 will be pulled down to close to 0V by the negative terminal P- / C- of the charging and discharging circuit. Therefore, when the falling edge is detected, the status monitoring terminal U2_17 of the status monitoring circuit 2 detects close to 0V for a certain period of time, and then the charging control terminal U1_47 is turned off and the discharging control terminal U1_44 is turned on, so that the battery pack can switch from charging to discharging. When the battery pack is in sleep mode, the voltage divider value is periodically scanned by the status monitoring terminal U2_17. When the voltage value enters the range of 1.2V-2.8V, it automatically enters the charging state and will remain in the charging state.

[0027] By incorporating a status monitoring circuit 2 within the main control circuit 1, in conjunction with the vehicle-mounted circuit 3 and the charging circuit 4, the power supply terminal U1_37 is kept powered after the battery pack is woken up, ensuring that the first wake-up terminal U2_40 and the status monitoring terminal U2_17 maintain a high voltage. The switching circuit 31 enables the first wake-up terminal U2_40 to detect a falling edge signal, thereby waking up the battery pack and controlling the discharge control terminal U1_44 to start discharging. The load circuit 41 enables the status monitoring terminal U2_17 to detect voltage changes when the charging circuit 4 is connected, and controls the charging control terminal U1_47 to start charging. The status monitoring circuit 2 performs the charging / discharging switching, resulting in greater circuit versatility and easier integration and removal of the battery pack. Furthermore, this method of battery pack integration requires no changes to software logic or hardware, and the circuit structure is simple.

[0028] Example 2: like Figure 2 As shown, this embodiment further optimizes and explains the circuit proposed in Embodiment 1: In some embodiments, the main control circuit 1 includes a first chip U1 and a second chip U2. A charging control terminal U1_47 and a discharging control terminal U1_44 are disposed on the first chip U1, and a first wake-up terminal U2_40 and a status detection terminal are disposed on the second chip U2. A status output terminal is connected to the second chip U2. A pull-up power supply terminal U1_37 is connected to the first chip U1. The first chip U1 is provided with a power output terminal, and the second chip U2 is provided with a power input terminal. The power output terminal is connected to the power input terminal so that when the battery pack is woken up, the first chip U1 supplies power to the second chip U2 and supplies power to the pull-up power supply terminal U1_37 to realize the battery pack wake-up.

[0029] Specifically, the first chip U1 is an AFE chip such as the BQ769X0 series, mainly responsible for sampling and protecting parameters such as voltage, current, and temperature of the battery pack. The second chip U2 is an MCU such as the STM32 series, enabling sampling, monitoring, and control of parameters such as voltage, current, and temperature of the battery pack. The first chip U1 outputs a power supply voltage to the power supply input of the second chip U2 through its power supply output terminal, enabling the first chip U1 to output the voltage required by the pull-up power supply terminal U1_37, which is typically 3.3V. Furthermore, the first chip U1 controls the battery pack to charge through the charging control terminal U1_47 and controls the battery pack to discharge through the discharging control terminal U1_44. Furthermore, the first chip U1 also includes the conventional peripheral circuitry of the AFE chip, and the second chip U2 also includes the conventional peripheral circuitry of the MCU, thereby maintaining the normal functions of the first chip U1 and the second chip U2, as well as the conventional connection between the AFE and the MCU, such as voltage detection lines, current detection lines, clock lines, etc. It also includes the conventional connection of the first chip U1 to the negative terminal B- of the battery pack, as well as the inherent grounding wire and filter capacitor of the first chip U1 and the second chip U2. The above are conventional settings and will not be described in detail here. A conventional data transmission channel is set between the first chip U1 and the second chip U2 to realize the data transmission of CAN communication, so that after the second chip U2 analyzes, the first chip U1 controls the switching on and off of charging and discharging. This connection is a conventional setting in the field when connecting the MCU and the AFE, and will not be described in detail here either.

[0030] In some embodiments, the main control circuit 1 further includes a first MOSFET Q1, a second MOSFET Q2, a first resistor R1, a second resistor R2, a third resistor R3, and a fourth resistor R4; the first resistor R1 and the second resistor R2 are connected in series and disposed between the positive terminal B+ of the battery pack and the charging control terminal U1_47; the gate of the first MOSFET Q1 is connected between the first resistor R1 and the second resistor R2, and the source of the first MOSFET Q1 is connected to the positive terminal B+ of the battery pack; the third resistor R3 and the fourth resistor R4 are connected in series and disposed between the positive terminal P+ / C+ of the charging and discharging circuit and the discharging control terminal U1_44; the gate of the second MOSFET Q2 is connected between the third resistor R3 and the fourth resistor R4, and the source of the second MOSFET Q2 is connected to the positive terminal P+ / C+ of the charging and discharging circuit; the drain of the first MOSFET Q1 and the drain of the second MOSFET Q2 are connected.

[0031] Specifically, the first MOSFET Q1 controls the charging state, and the second MOSFET Q2 controls the discharging state. These two MOSFETs are connected between the positive terminal B+ of the battery pack and the charging port, and their drains are connected to each other, causing them to conduct in opposite directions. This alters the flow direction of the circuit, enabling the switching between charging and discharging of the battery pack. Multiple parallel lines are placed on both sides of the source and drain of the MOSFETs to improve current carrying capacity. Furthermore, a first resistor R1 and a second resistor R2, a third resistor R3, and a fourth resistor R4 are connected in series on both sides of the first MOSFET Q1 and the second MOSFET Q2. Resistors R1 and R3 are pull-down resistors for protection drive, while R2 and R4 are current-limiting resistors for charging.

[0032] In some embodiments, the status monitoring circuit 2 includes a fifth resistor R5, a sixth resistor R6, and a first diode D1; One end of the fifth resistor R5 is connected to the pull-up power supply terminal U1_37, and the other end of the fifth resistor R5 is connected to the anode of the first diode D1 and one end of the sixth resistor R6; the other end of the sixth resistor R6 is the status output terminal and is connected to the first wake-up terminal U2_40 and the status monitoring terminal U2_17; the cathode of the first diode D1 is the status input terminal VLOCK.

[0033] Specifically, the fifth resistor R5 is a pull-up resistor, which can be selected from 1KΩ to 10KΩ; the sixth resistor R6 is a current-limiting resistor, which can be between 100Ω and 4.7KΩ; the first diode D1 is a high-voltage isolation diode, which can be a low-conductivity Schottky diode, mainly requiring low leakage current and a withstand voltage higher than twice the highest voltage of the battery pack. The sixth resistor R6 is mainly used for the condition monitoring circuit 2 to detect the voltage divider value.

[0034] In some embodiments, a wake-up circuit is also included. The wake-up circuit is provided with a second wake-up terminal and a wake-up input terminal. The second wake-up terminal is connected to the first chip U1, and the wake-up input terminal is connected to the positive terminal P+ / C+ of the charging and discharging circuit, so as to wake up the battery pack through the wake-up circuit.

[0035] In some embodiments, the wake-up circuit includes a seventh resistor R7, a Zener diode Z, an eighth resistor R8, a first capacitor C1, a second diode D2, and a ninth resistor R9. One end of the seventh resistor R7 is the wake-up input terminal, and the other end of the seventh resistor R7 is connected to the cathode of the Zener diode Z. The anode of the Zener diode Z is connected to one end of the eighth resistor R8 and the first capacitor C1. The other end of the eighth resistor R8 and the first capacitor C1 is connected to the anode of the second diode D2. The cathode of the second diode D2 is connected to one end of the ninth resistor R9. The other end of the ninth resistor R9 is the second wake-up terminal.

[0036] Specifically, a wake-up circuit is used to wake up the battery pack, and a wake-up signal is output to the first chip U1 through the second wake-up terminal. The wake-up input terminal is connected to the positive terminal of the charging and discharging circuit, that is, after the charger is plugged in, the positive terminal receives voltage from the wake-up input terminal. The seventh resistor R7 is a conventional resistor, which can be between 100Ω and 10KΩ. The Zener diode Z is a common diode with a Zener voltage between 2*n - over-discharge voltage*n, where n is the number of cells in series. The Zener diode Z is used to stabilize the voltage within a certain amplitude, but this amplitude does not meet the amplitude required by the wake-up signal output by the second wake-up terminal. The regulated voltage passes through the eighth resistor R8 and the first capacitor C1 in parallel to form an RC circuit. The eighth resistor R8 is used to store the discharge capacity, and the first capacitor C1 is used to isolate the charging signal pulse. After the first capacitor C1 is fully charged, an activation pulse is output. Only when the amplitude of this pulse meets the activation condition of the wake-up signal can the delayed wake-up function be achieved by controlling the charging time of the first capacitor C1. The second diode, D2, protects the circuit from reverse voltage flow and has a withstand voltage greater than twice the maximum voltage of the battery pack. The ninth resistor, R9, is a standard current-limiting and voltage-dividing resistor with a resistance range of 1KΩ-47KΩ.

[0037] In some embodiments, a communication circuit is also included, which includes a third chip U3, a third diode D3, and an eleventh resistor R11. The third chip U3 includes a first input terminal U3_1, a second input terminal U3_2, a communication output terminal U3_4, and a ground terminal U3_3. The third diode D3 is connected between the first input terminal U3_1 and the second input terminal U3_2, the eleventh resistor R11 is disposed on the first input terminal U3_1, and the communication output terminal U3_4 is connected to the second chip U2.

[0038] Specifically, the communication circuit can be used for communication between the battery pack and external circuits, and can be a CAN communication circuit. It mainly includes a third chip U3, which is used for communication signal isolation input. The first input terminal U3_1 is the CAN H terminal, and the second input terminal U3_2 is the CAN L terminal to generate a differential signal through the two ports. The communication output terminal U3_4 is connected to the second chip U2 and is used to communicate information such as the battery pack voltage and address. The third diode D3 is a conventional diode with a withstand voltage greater than twice the highest voltage of the battery pack, and the eleventh resistor has a resistance value between 1KΩ and 47KΩ. Furthermore, when the communication circuit is integrated into the vehicle, if the battery pack needs to discharge to the vehicle, the vehicle usually needs to press switch S1 for a certain period of time to determine whether the battery pack needs to be woken up from sleep mode to discharge. After pressing for a certain period, the MCU can determine whether to continue discharging by detecting the presence of the communication output terminal U3_4. At this time, the function of switch S1 can be ignored to avoid needing to keep the switch pressed to achieve continuous battery pack discharge.

[0039] Furthermore, during parallel connection, the communication circuit allows each battery pack to broadcast its own message. Successful connection is indicated by other battery packs being able to receive the message; failure indicates a communication breakdown. When multiple packs are connected in parallel, the communication circuit can pre-define communication addresses via a communication protocol to distinguish between different battery packs. It can also transmit the voltage level of its own battery pack to the outside world, allowing an additional equalization module to prioritize the discharge of high-voltage battery packs. In parallel connection, the size of the battery packs can also be used to determine if parallel connection is possible; generally, a voltage difference of less than 0.8V is required. The total pack size can also be calculated based on the voltage levels. This circuit enables control between battery packs.

[0040] In some embodiments, the load circuit 41 includes a tenth resistor R10, which is disposed between the second signal output terminal VLOCK2 and the negative terminal of the charging circuit 4. Specifically, the tenth resistor R10 is used to divide the voltage after the load circuit 41 is connected, so that the voltage drops to the required voltage value.

[0041] In some embodiments, the switching circuit 31 includes a switch S1 to switch the first signal output terminal VLOCK1 and the negative terminal P- / C- of the charging / discharging circuit on and off. The switching circuit 31 pulls down the voltage value of the first signal output terminal VLOCK1 to manually terminate charging on the vehicle and switch to vehicle discharge. Alternatively, by influencing the voltage value of VLOCK1 through S1, the battery pack is awakened from its dormant state (neither discharging nor charging) and put into full vehicle charging mode.

[0042] Example 3: like Figure 3 As shown, this embodiment proposes an electrical device, including a battery pack charging and discharging circuit as proposed in the first aspect, at least two battery packs, a charger, and an electrical device body; the status input terminals VLOCK of all battery packs are connected together, and the positive terminals B+ of all battery packs are connected to the positive terminals P+ / C+ of the charging and discharging circuit, and the negative terminals B- of all battery packs are connected to the negative terminals P- / C- of the charging and discharging circuit. The battery pack charging and discharging circuit is set between each battery pack, charger, and the main body of the electrical device to enable the battery pack to switch between charging and discharging. A voltage equalization module is set between the battery packs to ensure that the high-voltage battery pack is discharged first.

[0043] In some more specific embodiments, two battery packs are included. The positive terminals (B+) of the two battery packs are connected to the vehicle's discharge positive terminal and the charger's positive terminal on a single bus. The negative terminals of the two battery packs are connected to the vehicle's discharge negative terminal and the charger's negative terminal on a single bus. The first signal output terminal (VLOCK1) and the second signal output terminal (VLOCK2) are connected to the status input terminals (VLOCK) of the two battery packs. Furthermore, a CAN communication structure is also provided in the vehicle and the charger, with the CAN H connections of the battery packs, the vehicle, and the charger, and the CAN L connections of the battery packs, the vehicle, and the charger, to achieve connection between the battery pack, the charger, and the vehicle. When the battery packs are combined, the positive terminals (B+) and (B-) of the battery packs, the status input terminals (VLOCK), CAN H, and CAN L need to form a serial port, which can be plugged in to complete a simple connection.

[0044] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application.

Claims

1. A battery pack charging and discharging circuit, characterized in that, include: The main control circuit is equipped with a charging control terminal, a discharging control terminal, a first wake-up terminal, and a status monitoring terminal; The charging control terminal is used to control the charging of the battery pack, and the discharging control terminal is used to control the discharging of the battery pack. The status monitoring circuit is provided with a pull-up power supply terminal, a status input terminal, and a status output terminal; the pull-up power supply terminal is connected to the main control circuit; the status output terminal is connected to the first wake-up terminal and the status monitoring terminal. The vehicle-mounted circuit includes a first signal output terminal, a positive terminal of the charging and discharging circuit, and a negative terminal of the charging and discharging circuit; a switching circuit is provided between the first signal output terminal and the negative terminal of the charging and discharging circuit. The charging circuit is provided with a second signal output terminal; a load circuit is provided between the second signal output terminal and the negative terminal of the charging circuit. The first signal output terminal and the second signal output terminal are connected to the status input terminal; after the battery pack is woken up, the pull-up power supply terminal continues to supply power so that the first wake-up terminal and the status monitoring terminal maintain a high voltage; the switching circuit is used to enable the first wake-up terminal to detect a falling edge signal, thereby waking up the battery pack and controlling the discharge control terminal to start discharging; the load circuit is used to enable the status monitoring terminal to detect voltage changes when the charging circuit is connected and control the charging control terminal to start charging.

2. The battery pack charging and discharging circuit according to claim 1, characterized in that, The main control circuit includes a first chip U1 and a second chip U2. The charging control terminal and the discharging control terminal are disposed on the first chip U1, and the first wake-up terminal and the status detection terminal are disposed on the second chip U2. The status output terminal is connected to the second chip U2, and the pull-up power supply terminal is connected to the first chip U1. The first chip U1 is provided with a power output terminal, and the second chip U2 is provided with a power input terminal; the power output terminal is connected to the power input terminal so that when the battery pack is woken up, the first chip U1 supplies power to the second chip U2, and the first chip U1 supplies power to the pull-up power supply terminal to realize the battery pack wake-up.

3. The battery pack charging and discharging circuit according to claim 1, characterized in that, The main control circuit further includes a first MOSFET Q1, a second MOSFET Q2, a first resistor R1, a second resistor R2, a third resistor R3, and a fourth resistor R4; the first resistor R1 and the second resistor R2 are connected in series and disposed between the positive terminal of the battery pack and the charging control terminal; the gate of the first MOSFET Q1 is connected between the first resistor R1 and the second resistor R2, and the source of the first MOSFET Q1 is connected to the positive terminal of the battery pack; the third resistor R3 and the fourth resistor R4 are connected in series and disposed between the positive terminal of the charging and discharging circuit and the discharging control terminal; the gate of the second MOSFET Q2 is connected between the third resistor R3 and the fourth resistor R4, and the source of the second MOSFET Q2 is connected to the positive terminal of the charging and discharging circuit; the drain of the first MOSFET Q1 and the drain of the second MOSFET Q2 are connected.

4. The battery pack charging and discharging circuit according to claim 1, characterized in that, The status monitoring circuit includes a fifth resistor R5, a sixth resistor R6, and a first diode D1; One end of the fifth resistor R5 is connected to the pull-up power supply terminal, and the other end of the fifth resistor R5 is connected to the anode of the first diode D1 and one end of the sixth resistor R6; the other end of the sixth resistor R6 is the status output terminal and is connected to the first wake-up terminal and the status monitoring terminal; the cathode of the first diode D1 is the status input terminal.

5. The battery pack charging and discharging circuit according to claim 2, characterized in that, It also includes a wake-up circuit, which has a second wake-up terminal and a wake-up input terminal. The second wake-up terminal is connected to the first chip U1, and the wake-up input terminal is connected to the positive terminal of the charging and discharging circuit, so as to wake up the battery pack through the wake-up circuit.

6. The battery pack charging and discharging circuit according to claim 5, characterized in that, The wake-up circuit includes a seventh resistor R7, a Zener diode Z, an eighth resistor R8, a first capacitor C1, a second diode D2, and a ninth resistor R9. One end of the seventh resistor R7 is the wake-up input terminal, and the other end of the seventh resistor R7 is connected to the cathode of the Zener diode Z; the anode of the Zener diode Z is connected to one end of the eighth resistor R8 and the first capacitor C1, the other end of the eighth resistor R8 and the first capacitor C1 is connected to the anode of the second diode D2, the cathode of the second diode D2 is connected to one end of the ninth resistor R9, and the other end of the ninth resistor R9 is the second wake-up terminal.

7. The battery pack charging and discharging circuit according to claim 2, characterized in that, It also includes a communication circuit, which includes a third chip U3, a third diode D3, and an eleventh resistor R11; the third chip U3 includes a first input terminal, a second input terminal, a communication output terminal, and a ground terminal; the third diode D3 is connected between the first input terminal and the second input terminal, the eleventh resistor R11 is disposed on the first input terminal, and the communication output terminal is connected to the second chip U2.

8. The battery pack charging and discharging circuit according to claim 1, characterized in that, The load circuit includes a tenth resistor R10, which is disposed between the second signal output terminal and the negative terminal of the charging circuit.

9. The battery pack charging and discharging circuit according to claim 1, characterized in that, The switching circuit includes a switch S1 to switch the first signal output terminal and the negative terminal of the charging and discharging circuit on and off.

10. An electrical appliance, characterized in that, Includes a battery pack charging and discharging circuit as described in any one of claims 1-9, at least two battery packs, a charger, and a power device body; the status input terminals of all the battery packs are connected together, and the positive terminals of all the battery packs are connected to the positive terminal of the charging and discharging circuit, and the negative terminals of all the battery packs are connected to the negative terminal of the charging and discharging circuit. The battery pack charging and discharging circuit is disposed between each battery pack, the charger, and the electrical device body, so that the battery pack can switch between charging and discharging through the battery pack charging and discharging circuit. A voltage equalization module is disposed between the battery packs so that the high-voltage battery pack is discharged first.

Images