Battery management circuit module and mobile power supply equipment

Abstract

The invention discloses a battery management circuit module and mobile power supply equipment. The battery management circuit module comprises an external connection port, a battery connection port, a bidirectional power conversion unit, a charging and discharging switch unit, a non-resettable fusing unit and an intelligent management unit. Wherein the bidirectional power conversion unit is used for performing bidirectional voltage conversion between an external connection port and a power bus node; the charging and discharging switch unit and the non-resettable fusing unit are connected in series between the power bus node and the positive electrode interface of the battery connection port to form a high-side protection framework; the intelligent management unit is used for calculating the electric quantity state based on an impedance tracking algorithm and outputting a driving signal to the non-resettable fusing unit when a fault is detected. According to the invention, a high-side protection architecture is adopted to ensure stable communication, and a fault loop is physically cut off in combination with an active fusing mechanism, so that the safety and reliability of high-power fast charging are improved.

Description

Technical Field

[0001] This invention relates to the field of power management technology, and in particular to a battery management circuit module and a mobile power supply device. Background Technology

[0002] With the widespread adoption of the USB PD (Power Delivery) fast charging protocol, power banks that support high-power charging and discharging (such as 4-cell lithium battery power banks for laptop charging) have become the mainstream in the market. These devices typically need to support bidirectional input and output over a wide voltage range of 5V to 20V, placing extremely high demands on the safety and accuracy of the battery management system (BMS).

[0003] Battery management solutions in related technologies typically employ an architecture of microcontroller, buck-boost converter, and low-side protection. However, in this architecture, the protection switch is usually located in the battery negative terminal circuit (low-side drive), causing the battery negative terminal to float above system ground when the protection is disconnected. This can easily interfere with the stability of communication buses such as SMBus or I2C, resulting in abnormal data reading. Furthermore, the safety mechanism mainly relies on MOSFET switches for soft cutoff. However, in high-voltage fast charging scenarios, once a power device breaks down and short-circuits, the battery pack will be directly exposed to external high voltage, lacking an irreversible physical cutoff mechanism, posing a fire and explosion hazard. Summary of the Invention

[0004] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, the object of this invention is to provide a battery management circuit module and a mobile power supply device.

[0005] To achieve the above objectives, in one aspect, a battery management circuit module according to an embodiment of the present invention includes: External connection port, used to connect to external power supply or external load; The battery connection port includes a positive terminal interface for connecting to the positive terminal of the battery pack and a negative terminal interface for connecting to the negative terminal of the battery pack. A bidirectional power conversion unit is electrically connected between the external connection port and the power bus node, and is used for voltage conversion; A charge / discharge switch unit is connected in series between the power bus node and the positive terminal interface; A non-resettable fuse unit is connected in series in the power transmission path between the power bus node and the positive terminal interface; And an intelligent management unit, which is connected to the charging and discharging switch unit and the battery connection port respectively, for collecting voltage data through the battery connection port and calculating the power status based on the impedance tracking algorithm; The intelligent management unit is further provided with a fuse control terminal, which is configured to output a drive signal to the non-resettable fuse unit when a fault is detected, so as to physically fuse the power transmission path.

[0006] In addition, the battery management circuit module according to the above embodiments of the present invention may also have the following additional technical features: According to one embodiment of the present invention, the charge / discharge switch unit includes a first N-type field-effect transistor and a second N-type field-effect transistor connected back-to-back in series; The intelligent management unit has a charge pump drive circuit, which is connected to the gates of the first N-type field-effect transistor and the second N-type field-effect transistor via a high-side drive method.

[0007] According to one embodiment of the present invention, the non-resettable fuse unit includes a three-terminal chemical fuse, the three-terminal chemical fuse comprising a fuse body connected in series in the power transmission path, and a self-heating resistor for triggering the fuse body to melt; one end of the self-heating resistor is connected to the fuse body, and the other end is connected to the fuse control terminal of the intelligent management unit.

[0008] According to one embodiment of the present invention, it further includes a current sampling unit, the current sampling unit including a sampling resistor connected in series in the loop of the negative terminal interface; The intelligent management unit is connected to both ends of the sampling resistor via two sensing lines, forming a Kelvin connection structure.

[0009] According to one embodiment of the present invention, the bidirectional power conversion unit includes a Buck-Boost controller and a power inductor connected thereto; the Buck-Boost controller is used to drive the power inductor to store and release energy, so as to convert the voltage input to the external connection port into a charging voltage adapted to the battery connection port, or to convert the voltage of the battery connection port into a target output voltage and output it to the external connection port.

[0010] According to one embodiment of the present invention, a secondary protection circuit is further included, which is independent of the intelligent management unit and is connected in parallel between the positive interface and the negative interface; The secondary protection circuit is used to independently monitor the voltage of each cell connected through the battery connection port. When an overvoltage fault is detected, the output signal triggers the non-resettable fuse unit to operate.

[0011] According to one embodiment of the present invention, the battery connection port further includes a plurality of voltage sampling terminals for connecting cell nodes; The intelligent management unit includes multiple voltage detection pins, and each voltage detection pin is connected to the corresponding voltage sampling terminal through an RC filter circuit. The intelligent management unit also has a balancing switch. When the voltage difference between any two cells exceeds a preset threshold, the balancing switch is turned on to passively balance the cell with the higher voltage.

[0012] According to one embodiment of the present invention, a main control unit is further included. The main control unit is connected to the bidirectional power conversion unit and the intelligent management unit respectively via a communication bus, and is used to read the relative state of charge and health data calculated by the intelligent management unit.

[0013] According to one embodiment of the present invention, the external connection port is a Type-C interface; the Type-C interface includes configuration channel pins, and the configuration channel pins are connected to filter capacitors; the data transmission pins of the Type-C interface are connected to ESD electrostatic protection devices.

[0014] On the other hand, a mobile power supply device according to an embodiment of the present invention includes: case; A multi-cell lithium battery pack connected in series is housed within the casing; And the battery management circuit module as described above; the battery management circuit module is disposed inside the housing, the positive terminal of the multi-cell series-connected lithium battery pack is electrically connected to the positive terminal interface, and the negative terminal of the multi-cell series-connected lithium battery pack is electrically connected to the negative terminal interface.

[0015] The battery management circuit module and mobile power device provided in this embodiment of the invention form a high-side protection architecture by connecting the charge / discharge switch unit and the non-resettable fuse unit in series between the power bus node and the positive terminal interface. This effectively maintains the connection between the battery negative terminal and the system ground, preventing communication interference caused by ground potential fluctuations in traditional low-side protection. Simultaneously, the impedance tracking of the intelligent management unit achieves high-precision power metering through real-time monitoring of internal resistance. Furthermore, the active fuse control mechanism of the intelligent management unit can actively drive the non-resettable fuse unit to physically cut off the high-power transmission path when uncontrollable faults such as soft switch failure or severe overvoltage are detected. This prevents the risk of battery thermal runaway caused by short circuits in power devices during bidirectional high-power fast charging scenarios, improving safety redundancy and operational reliability.

[0016] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0018] Figure 1 This is a schematic block diagram of the battery management circuit module in an embodiment of the present invention; Figure 2 This is a circuit diagram of the bidirectional power conversion unit in the battery management circuit module of this invention embodiment; Figure 3 This is a circuit diagram of the charge / discharge switch unit, the non-resettable fuse unit, and the intelligent management unit in the battery management circuit module of this embodiment of the invention. Figure 4 This is a circuit diagram of the secondary protection circuit in the battery management circuit module in this embodiment of the invention; Figure 5 This is a circuit diagram of the main control unit in the battery management circuit module of this invention embodiment.

[0019] Figure label: 10. External connection port; 11. Battery connection port; 20. Bidirectional power conversion unit; 30. Charge / discharge switch unit; 40. Non-resettable fuse unit; 50. Intelligent management unit; 60. Secondary protection circuit; 70. Main control unit.

[0020] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0021] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0022] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "circumferential," and "radial," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0023] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0024] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., 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 or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0025] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0026] The battery management circuit module and the mobile power supply device having the same are described in detail below with reference to the accompanying drawings.

[0027] Reference Figures 1 to 5As shown, the battery management circuit module provided according to an embodiment of the present invention includes an external connection port 10, a battery connection port 11, a bidirectional power conversion unit 20, a charge / discharge switch unit 30, a non-resettable fuse unit 40, and an intelligent management unit 50.

[0028] Specifically, external connection port 10 is used to connect to an external power source or an external load. Through this external connection port 10, an external power source (such as an adapter) can be connected to receive charging energy to charge the battery pack, or an external load (such as a laptop, mobile phone, etc.) can be connected to supply power to the external load. Battery connection port 11 includes a positive interface (BAT+) for connecting to the positive terminal of the battery pack and a negative interface (BAT-) for connecting to the negative terminal of the battery pack. For example, external connection port 10 is a USB Type-C female connector, and its internal configuration channel pins (CC1, CC2) are equipped with a filter capacitor connected in parallel. This filter capacitor is located close to the interface and is used to filter out high-frequency noise to ensure the stability of the PD protocol handshake. Simultaneously, an ESD protection device (such as a TVS diode) is connected in parallel between the data transmission pin (DP / DM) of external connection port 10 and ground. This device can instantly conduct and discharge surge current when an electrostatic pulse is detected, thereby protecting the backend chip from damage.

[0029] This embodiment effectively solves the communication instability problem caused by noise by deploying a filter capacitor on the CC line and setting ESD protection on the data line, and builds a solid electrostatic protection barrier, significantly improving the electromagnetic compatibility and anti-interference reliability of the module.

[0030] A bidirectional power conversion unit 20 is electrically connected between the external connection port 10 and the power bus node for voltage conversion. This bidirectional power conversion unit 20, according to instructions from the intelligent management unit 50, can convert various voltages (e.g., 5V-20V) input to the external connection port 10 into a charging voltage suitable for the battery pack in charging mode; and in discharging mode, it converts the battery pack voltage into a stable output voltage required by the external load. By adopting this bidirectional conversion topology, the problem of voltage mismatch between the external environment and the battery is effectively solved, and the power conversion efficiency is improved.

[0031] A charge / discharge switch unit 30 is connected in series between the power bus node and the positive terminal interface (BAT+). This charge / discharge switch unit 30 is used to turn on the circuit during normal charging and discharging, and to perform a recoverable shutdown action when overcharging, over-discharging, or general overcurrent is detected. Because the switching device is located in the positive terminal circuit, the negative terminal of the battery pack is always connected to system ground (GND) with low impedance, thereby ensuring the stability of the reference potential of communication buses such as SMBus and I2C, and preventing communication interruption or data misreading caused by protection actions.

[0032] A non-resettable fuse unit 40 is connected in series on the power transmission path between the power bus node and the positive terminal interface. Unlike ordinary resettable fuses, this non-resettable fuse unit 40 is located in the series circuit of the charge / discharge switch unit 30. When serious faults such as MOSFET breakdown and short circuit or MCU crash leading to loss of control occur in the system, and conventional electronic switches cannot cut off the circuit, this non-resettable fuse unit 40 physically melts the circuit, isolates battery energy, and prevents thermal runaway or fire accidents.

[0033] The intelligent management unit 50 is signal-connected to both the charge / discharge switch unit 30 and the battery connection port 11. It is used to acquire voltage data through the battery connection port 11 and calculate the battery status based on an impedance tracking algorithm. Specifically, the intelligent management unit 50 uses a fuel gauge chip U3 (model BQ40Z50R1) to acquire the total voltage of the battery pack, the voltage of each individual cell, and the loop current data in real time via the battery connection port 11 (pins VC1 to VC4) through an ADC sampling channel. Furthermore, the intelligent management unit 50 integrates an impedance tracking algorithm, which can dynamically correct the battery's remaining capacity (SOC) and state of health (SOH) models by combining real-time current integration, temperature data, and changes in battery internal resistance. This allows it to provide accurate battery level display and range prediction even under conditions of battery aging or drastic temperature changes.

[0034] The intelligent management unit 50 also has a fuse control terminal (FUSE pin), configured to output a drive signal to the non-resettable fuse unit 40 when a fault is detected, to physically break the power transmission path. During use, the intelligent management unit 50 continuously monitors the circuit status. Once a serious fault is detected (e.g., the charging voltage continuously exceeds the safety threshold and the charge / discharge switch unit 30 does not respond, or a power transistor is detected to be short-circuited), the intelligent management unit 50 will immediately output a high level or drive signal through the fuse control terminal to drive the heating element inside the non-resettable fuse unit 40 to activate, quickly breaking the fuse in the main circuit, thereby completing the physical breaking of the power transmission path in a very short time to ensure safety.

[0035] According to the battery management circuit module provided in this embodiment of the invention, by connecting the charge / discharge switch unit 30 and the non-resettable fuse unit 40 in series between the power bus node and the positive terminal interface, a high-side protection architecture is formed. This effectively maintains the connection between the battery negative terminal and the system ground, preventing communication interference caused by ground potential fluctuations in traditional low-side protection. At the same time, the impedance tracking of the intelligent management unit 50 achieves high-precision power metering by monitoring the internal resistance in real time. The active fuse control mechanism of the intelligent management unit 50 can actively drive the non-resettable fuse unit 40 to operate when it detects uncontrollable faults such as soft switch failure or severe overvoltage, physically cutting off the high-power transmission path. This prevents the risk of battery thermal runaway caused by short circuits in power devices in bidirectional high-power fast charging scenarios, improving safety redundancy and operational reliability.

[0036] In one embodiment of the present invention, the charge / discharge switch unit 30 includes a first N-type field-effect transistor and a second N-type field-effect transistor connected back-to-back in series.

[0037] The intelligent management unit 50 has a charge pump drive circuit, which is connected to the gates of the first N-type field-effect transistor and the second N-type field-effect transistor via a high-side drive method (CHG pin, DSG pin).

[0038] In other words, the charge / discharge switching unit 30 uses N-channel field-effect transistors (FETs) as power switching devices, and its circuit topology is a back-to-back series configuration. The sources of the first N-type FET and the second N-type FET are connected to each other, forming a common-source structure. The drain of the first N-type FET is connected to one side of the power bus node, while the drain of the second N-type FET is connected to the positive terminal of the battery pack. This common-source connection allows the gates of the two FETs to share a common drive signal reference point, thus simplifying the wiring of the drive circuit. Simultaneously, the parasitic body diodes inside the two FETs are oriented in opposite directions. When both FETs are simultaneously in the off state, the charge / discharge circuit can be completely cut off, preventing current leakage in any single direction during charging or discharging, thus effectively blocking bidirectional current.

[0039] To drive the N-type field-effect transistor (FET) positioned on the high side of the power supply, the intelligent management unit 50 integrates a dedicated charge pump drive circuit. Since the N-type FET is located in the high-potential loop of the battery pack's positive electrode, its conduction condition requires the gate voltage to be higher than the source voltage by a threshold voltage. When the battery pack voltage is high, ordinary logic levels cannot directly drive the FET at this location. Therefore, the charge pump drive circuit is configured to boost the input low-voltage power supply or battery voltage to generate a drive voltage higher than the positive electrode voltage of the battery pack. This drive voltage is simultaneously coupled to the gates of the first and second N-type FETs via the high-side drive line, ensuring that the FET operates in the deep linear region when turned on, where its drain-source on-resistance is minimized.

[0040] During operation, the intelligent management unit 50 dynamically controls the operating state of the charge pump drive circuit based on monitored real-time voltage, current, and temperature parameters. In normal charging or discharging mode, the intelligent management unit 50 activates the charge pump drive circuit, outputting a high voltage to the gate, causing the first and second N-type field-effect transistors to conduct simultaneously, thus activating the power transmission path. When abnormal faults such as overcharging, over-discharging, short circuit, or over-temperature are detected, the intelligent management unit 50 immediately shuts down the charge pump drive circuit and controls the gate to discharge, rapidly lowering the gate-source voltage and forcing the first and second N-type field-effect transistors into the cutoff state, thereby protecting the downstream circuitry and battery pack. Furthermore, a Zener diode and a bleeder resistor are typically connected in parallel between the gate and source to prevent excessive gate voltage from breaking down the oxide layer and to ensure rapid discharge of the gate charge when the drive signal is withdrawn, improving the turn-off speed.

[0041] In one embodiment of the present invention, the non-resettable fuse unit 40 includes a three-terminal chemical fuse (PTC) comprising a fuse body connected in series in the power transmission path and a self-heating resistor for triggering the fuse body to melt. One end of the self-heating resistor is connected to the fuse body, and the other end is connected to the fuse control terminal of the intelligent management unit 50.

[0042] In practical circuit applications, this connection path typically includes a low-power switching transistor to receive the drive level from the intelligent management unit 50. When the intelligent management unit 50 detects an irreversible fault such as severe overcharging, overvoltage, or short circuit in the power MOSFET of the charge / discharge switching unit 30, it outputs a high-level signal or trigger signal to the fuse control terminal. This signal activates the self-heating resistor's circuit, causing current to flow through it and rapidly generating high-temperature Joule heat. Due to the efficient heat conduction structure between the self-heating resistor and the fuse body, the generated high temperature is instantly transferred to the fuse body. Combined with the internally encapsulated fluxing chemicals, the fuse body melts and physically breaks in a very short time, thereby severing the electrical connection between the battery pack and the external port.

[0043] The three-terminal chemical fuse with a self-heating resistor used in this embodiment, through active control by the intelligent management unit 50, solves the problems of slow melting speed, large influence of ambient temperature on the melting threshold, and inability to cope with small current overvoltage faults of traditional passive fuses. Utilizing the triggering of electrothermal melting, irreversible physical isolation of the power circuit can be implemented in extreme conditions such as short circuits caused by charge / discharge switch failure. This greatly reduces the safety hazards of battery fires caused by continuous overcharging or short circuits, and improves the safety redundancy of the entire battery management system.

[0044] In one embodiment of the present invention, the battery management circuit module further includes a current sampling unit, which includes a sampling resistor connected in series in the loop of the negative terminal interface. Both the charging current flowing into the battery from an external power source and the discharging current output by the battery to the load must flow through this sampling resistor, thereby generating a voltage drop signal across its terminals that is proportional to the current magnitude. To accommodate high-current applications, this sampling resistor is typically a milliohm-level (e.g., 1mΩ to 10mΩ) metal plate or metal film resistor to ensure sampling accuracy while minimizing power loss and heat generation.

[0045] The intelligent management unit 50 is connected to both ends of the sampling resistor via two sensing lines (SRP pin and SRN pin), forming a Kelvin connection structure. That is, the two sensing lines from the intelligent management unit 50 are not directly connected to the power pads or main current traces of the sampling resistor, but are independently connected to the voltage sensing point inside the sampling resistor. On the PCB layout, the two sensing lines are typically tightly coupled differential pairs, extending in parallel and of equal length to the analog-to-digital converter (ADC) input terminal inside the intelligent management unit 50. The intelligent management unit 50 directly reads the voltage difference across the sampling resistor via the two high-impedance sensing lines, uses differential amplification to filter out common-mode interference, and calculates the instantaneous current value and cumulative charge.

[0046] This embodiment employs a sampling resistor based on the negative electrode circuit combined with a Kelvin connection structure, which improves the metering accuracy of battery management. The Kelvin connection effectively separates the power circuit through which a large current flows from the detection circuit through which a micro-voltage signal is transmitted, avoiding measurement errors introduced by changes in PCB copper foil resistance and pad contact resistance with current and temperature, and ensuring the accuracy of the microvolt-level voltage signal.

[0047] In one embodiment of the present invention, the bidirectional power conversion unit 20 includes a Buck-Boost controller and a power inductor connected thereto. The Buck-Boost controller is used to drive the power inductor to store and release energy, so as to convert the voltage input to the external connection port 10 into a charging voltage adapted to the battery connection port 11, or to convert the voltage of the battery connection port 11 into a target output voltage and output it to the external connection port 10.

[0048] In this embodiment, the bidirectional power conversion unit 20 adopts a synchronous buck-boost circuit topology, including a highly integrated Buck-Boost controller chip (such as the SC8815QDER chip) and a power inductor (e.g., a power inductor with an inductance of approximately 4.7uH) that works in conjunction with it. The Buck-Boost controller is connected to an H-bridge switching array composed of four power transistors via a drive interface. This H-bridge switching array is divided into an input-side half-bridge and an output-side half-bridge, with the power inductor connected in series between the midpoint of the input-side half-bridge and the midpoint of the output-side half-bridge. The Buck-Boost controller integrates a pulse width modulation generator and a logic control unit, which can dynamically adjust the turn-on and turn-off timing and duty cycle of each power transistor in the H-bridge based on the detected real-time voltage difference between the input and output voltages, thereby precisely controlling the power inductor to perform high-frequency energy storage and release cycles.

[0049] When the circuit is in charging mode, the Buck-Boost controller uses the external power supply voltage input to the external connection port 10 as its input source. Regardless of whether the external input voltage is lower, higher, or equal to the current battery pack voltage (e.g., the external input range is 5V-20V), the Buck-Boost controller can automatically switch to Boost, Buck, or Buck-Boost buck-boost modes to pump energy to the battery connection port 11, thus charging the battery pack. Conversely, when the circuit is in reverse discharge mode, the Buck-Boost controller uses the battery voltage at the battery connection port 11 as its input source, driving the power inductor to reverse-transfer energy, converting the fluctuating battery voltage as the charge level decreases into a stable target voltage (such as a fixed 5V, 9V, or 12V) that meets the requirements of fast charging protocols such as USB PD, and outputting it to the external connection port 10 to supply external loads.

[0050] This embodiment utilizes a bidirectional conversion structure composed of a Buck-Boost controller and a power inductor, which features an extremely wide voltage regulation range and bidirectional energy flow capability. This not only achieves compatibility with external adapters of different specifications, ensuring efficient charging throughout the entire battery voltage variation process, but also guarantees low ripple and high stability in the external discharge output voltage, improving the energy conversion efficiency and user experience of the battery management module in fast-charging applications.

[0051] In one embodiment of the present invention, the battery management circuit module further includes a secondary protection circuit 60, which is independent of the intelligent management unit 50 and is connected in parallel between the positive terminal interface and the negative terminal interface.

[0052] The secondary protection circuit 60 is used to independently monitor the voltage of each cell connected through the battery connection port 11. When an overvoltage fault is detected, the output signal triggers the non-resettable fuse unit 40 to operate.

[0053] Specifically, the secondary protection circuit 60 mainly consists of a battery protection chip (such as the BQ296115 series chip) and its peripheral RC filter network. Its power input terminal and voltage detection terminal (VDD, V4, V3, V2) are connected in parallel with each individual cell in the battery pack (via CELL1 to CELL3 and BAT+). The operation of the secondary protection circuit 60 does not depend on the clock signal, firmware program, or communication bus of the intelligent management unit 50, but rather on an independent internal reference voltage source and voltage comparator array. Even if the intelligent management unit 50 crashes, malfunctions, or stops oscillating due to strong external interference, or if the system is in deep sleep mode and unable to execute the main protection logic, the secondary protection circuit 60 can still maintain a continuous online monitoring state relying on the battery's own power, thus forming another line of defense for battery safety management.

[0054] The secondary protection circuit 60 collects real-time voltage data of each cell in the battery pack through independent voltage sampling lines, monitoring the voltage of each individual cell. When the voltage of any cell rises and exceeds a preset threshold, and the duration of this overvoltage state exceeds the preset anti-interference delay time (e.g., 1 to 2 seconds) inside the battery protection chip, it is determined that the current state is an extremely dangerous overcharge state. At this time, the battery protection chip outputs a drive signal through its output pin (OUT pin). This drive signal directly turns on the drive switch in the heating resistor circuit of the non-resettable fuse unit 40, thereby triggering the self-heating resistor to heat up and forcibly blow the physical circuit.

[0055] This embodiment introduces a secondary protection circuit 60 that is electrically isolated from and logically independent of the intelligent management unit 50, and directly drives it to the non-resettable fuse unit 40, thereby achieving dual safety redundancy of the battery management system and preventing the risk of single-point failure.

[0056] In one embodiment of the present invention, the battery connection port 11 further includes a plurality of voltage sampling terminals (CELL1 to CELL3 and BAT+) for connecting cell nodes.

[0057] The intelligent management unit 50 includes multiple voltage detection pins (VC1-VC4), each of which is connected to the corresponding voltage sampling terminal through an RC filter circuit.

[0058] The intelligent management unit 50 also has a balancing switch. When the voltage difference between any two cells exceeds a preset threshold, the balancing switch is turned on to passively balance the cell with the higher voltage.

[0059] The intelligent management unit 50 (e.g., the BQ40Z50R1 chip) integrates multiple analog-to-digital converter (ADC) sampling interfaces. Each ADC interface serves as a voltage detection pin, monitoring the voltage state of a single battery cell. To ensure the accuracy and stability of the sampled data, an RC low-pass filter circuit, consisting of resistors and capacitors, is connected in series between each voltage sampling pin and the corresponding voltage detection pin of the intelligent management unit 50. This RC filter circuit filters out switching noise caused by the high-frequency switching of the power switching transistors during charging and discharging, as well as voltage spike interference caused by load changes. It smooths the acquired analog voltage signal before transmitting it to the ADC interface, enabling the intelligent management unit 50 to read a clean and stable DC voltage value.

[0060] To address the capacity imbalance issue caused by differences in internal resistance and self-discharge rate among individual cells in multi-cell lithium battery packs during use, the intelligent management unit 50 incorporates multiple equalization switches. Each equalization switch is connected in series with a power-dissipating resistor and then in parallel across the corresponding individual cell. The intelligent management unit 50 runs a voltage equalization algorithm that calculates and compares the voltage values ​​of each individual cell in real time. When the intelligent management unit 50 detects that the voltage difference between the highest and lowest voltage cells in the battery pack exceeds a preset equalization activation threshold, it determines that the battery pack is in an unbalanced state. At this time, the intelligent management unit 50 outputs a control signal to activate the equalization switch connected in parallel with the one or more cells with the higher voltage. After activation, some charging current or stored charge flows through the power-dissipating resistor and dissipates as heat, thereby reducing the terminal voltage of the high-voltage cell or slowing its voltage rise rate until the voltage difference among the individual cells falls back to within the preset stop threshold range, achieving cell voltage consistency.

[0061] This embodiment improves the sampling accuracy of battery management and extends the lifespan of the battery pack by setting up an RC filter circuit on the sampling path and introducing a passive equalization mechanism based on voltage difference triggering in the control logic. The RC filter circuit effectively reduces the impact of high-frequency interference on ADC sampling, ensuring the accuracy of voltage judgment and preventing false equalization triggering caused by spurious voltage fluctuations. The passive equalization strategy prevents individual cells from prematurely aging due to prolonged overcharging or over-discharging, thereby maximizing the overall usable capacity of the battery pack and extending the module's charge-discharge cycle.

[0062] In one embodiment of the present invention, the battery management circuit module further includes a main control unit 70, which is connected to the bidirectional power conversion unit 20 and the intelligent management unit 50 respectively via a communication bus, and is used to read the relative state of charge and health data calculated by the intelligent management unit 50.

[0063] Specifically, the main control unit 70 (e.g., a CSP32G230 chip) communicates with the bidirectional power conversion unit 20 and the intelligent management unit 50 via a digital communication bus (such as an I2C bus or an SMBus bus). The main control unit 70 can read battery parameters calculated in real time by the intelligent management unit 50 based on an impedance tracking algorithm through the communication bus in a periodic polling or interrupt-triggered manner. These parameters include at least the relative state of charge reflecting the remaining battery capacity percentage and health data reflecting the ratio of the battery's current maximum usable capacity to its factory nominal capacity.

[0064] In practical applications, on the one hand, the main control unit 70 can map the read relative state of charge data into a visual signal, driving an LED indicator array or display screen through pins (LED_CTL1 to LED_CTL5) to intuitively display the current battery level to the user. On the other hand, based on the battery health data and real-time status, the main control unit 70 sends control commands to the bidirectional power conversion unit 20 via the communication bus to dynamically adjust the charging and discharging strategy. For example, when a decline in battery health is detected, the main control unit 70 can instruct the bidirectional power conversion unit 20 to reduce the constant current setting value during charging to delay battery aging; or during external discharge, it can intelligently adjust the power configuration data packet broadcast by the PD protocol according to the remaining power level to prevent undervoltage protection from being triggered due to forced high power output in a low power state.

[0065] This embodiment coordinates the bidirectional power conversion unit 20 and the intelligent management unit 50 through the main control unit 70, realizing a hierarchical architecture that separates metering and control. By fully utilizing the advantages of the intelligent management unit 50, the accuracy of SOC and SOH data is ensured. Meanwhile, the main control unit 70 can implement flexible charging and discharging strategies and human-machine interaction, not only improving the user experience but also achieving refined management of the battery's entire lifecycle, optimizing overall energy efficiency and operational safety.

[0066] This invention also provides a mobile power supply device, including a housing, a multi-cell series-connected lithium battery pack, and a battery management circuit module as described in the above embodiments. The lithium battery pack is housed within the housing; the battery management circuit module is disposed within the housing; the positive terminal of the multi-cell series-connected lithium battery pack is electrically connected to the positive terminal interface, and the negative terminal of the multi-cell series-connected lithium battery pack is electrically connected to the negative terminal interface.

[0067] According to the mobile power supply device provided in the embodiments of the present invention, by connecting the charge / discharge switch unit 30 and the non-resettable fuse unit 40 in series between the power bus node and the positive terminal interface, a high-side protection architecture is formed, which effectively maintains the connection between the battery negative terminal and the system ground, and prevents communication interference problems caused by ground potential fluctuations in traditional low-side protection. At the same time, the impedance tracking of the intelligent management unit 50 achieves high-precision power metering by monitoring the internal resistance in real time. The active fuse control mechanism of the intelligent management unit 50 can actively drive the non-resettable fuse unit 40 to operate when it detects uncontrollable faults such as soft switch failure or severe overvoltage, physically cutting off the high-power transmission path. This prevents the risk of battery thermal runaway caused by short circuits of power devices in bidirectional high-power fast charging scenarios, and improves safety redundancy and operational reliability.

[0068] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0069] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A battery management circuit module, characterized in that, include: External connection port, used to connect to external power supply or external load; The battery connection port includes a positive terminal interface for connecting to the positive terminal of the battery pack and a negative terminal interface for connecting to the negative terminal of the battery pack. A bidirectional power conversion unit is electrically connected between the external connection port and the power bus node, and is used for voltage conversion; A charge / discharge switch unit is connected in series between the power bus node and the positive terminal interface; A non-resettable fuse unit is connected in series in the power transmission path between the power bus node and the positive terminal interface; And an intelligent management unit, which is connected to the charging and discharging switch unit and the battery connection port respectively, for collecting voltage data through the battery connection port and calculating the power status based on the impedance tracking algorithm; The intelligent management unit is further provided with a fuse control terminal, which is configured to output a drive signal to the non-resettable fuse unit when a fault is detected, so as to physically fuse the power transmission path.

2. The battery management circuit module according to claim 1, characterized in that, The charge / discharge switch unit includes a first N-type field-effect transistor and a second N-type field-effect transistor connected back-to-back in series; The intelligent management unit has a charge pump drive circuit, which is connected to the gates of the first N-type field-effect transistor and the second N-type field-effect transistor via a high-side drive method.

3. The battery management circuit module according to claim 1, characterized in that, The non-resettable fuse unit includes a three-terminal chemical fuse, which includes a fuse body connected in series in the power transmission path and a self-heating resistor for triggering the fuse body to melt; one end of the self-heating resistor is connected to the fuse body, and the other end is connected to the fuse control terminal of the intelligent management unit.

4. The battery management circuit module according to claim 1, characterized in that, It also includes a current sampling unit, which includes a sampling resistor connected in series in the loop of the negative terminal interface; The intelligent management unit is connected to both ends of the sampling resistor via two sensing lines, forming a Kelvin connection structure.

5. The battery management circuit module according to claim 1, characterized in that, The bidirectional power conversion unit includes a Buck-Boost controller and a power inductor connected thereto; the Buck-Boost controller is used to drive the power inductor to store and release energy, so as to convert the voltage input to the external connection port into a charging voltage adapted to the battery connection port, or to convert the voltage of the battery connection port into a target output voltage and output it to the external connection port.

6. The battery management circuit module according to claim 1, characterized in that, It also includes a secondary protection circuit, which is independent of the intelligent management unit and is connected in parallel between the positive interface and the negative interface; The secondary protection circuit is used to independently monitor the voltage of each cell connected through the battery connection port. When an overvoltage fault is detected, the output signal triggers the non-resettable fuse unit to operate.

7. The battery management circuit module according to claim 1, characterized in that, The battery connection port also includes multiple voltage sampling terminals for connecting cell nodes; The intelligent management unit includes multiple voltage detection pins, and each voltage detection pin is connected to the corresponding voltage sampling terminal through an RC filter circuit. The intelligent management unit also has a balancing switch. When the voltage difference between any two cells exceeds a preset threshold, the balancing switch is turned on to passively balance the cell with the higher voltage.

8. The battery management circuit module according to claim 1, characterized in that, It also includes a main control unit, which is connected to the bidirectional power conversion unit and the intelligent management unit respectively via a communication bus, and is used to read the relative state of charge and health data calculated by the intelligent management unit.

9. The battery management circuit module according to claim 1, characterized in that, The external connection port is a Type-C interface; the Type-C interface includes configuration channel pins, which are connected to filter capacitors; the data transmission pins of the Type-C interface are connected to ESD electrostatic protection devices.

10. A portable power bank device, characterized in that, include: case; A multi-cell lithium battery pack connected in series is housed within the casing; And the battery management circuit module as described in any one of claims 1 to 9; The battery management circuit module is disposed inside the housing. The positive terminal of the multi-cell series-connected lithium battery pack is electrically connected to the positive terminal interface, and the negative terminal of the multi-cell series-connected lithium battery pack is electrically connected to the negative terminal interface.

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