Charging circuit and battery device

Abstract

The application discloses a charging circuit and a battery device, and relates to the technical field of battery devices. The charging circuit comprises a switching power supply module, a power gauge module and a main control module. The switching power supply module is used for converting an input external power supply into a charging power supply and outputting the charging power supply to a battery; the power gauge module is used for collecting charging parameters of the battery in a charging process and outputting corresponding charging parameter detection signals to the main control module; the main control module determines the charging parameters of the current battery according to the charging parameter detection signals, determines the health state of the current battery according to the charging parameters of the current battery and pre-stored battery factory charging parameters, and controls the working of the switching power supply module according to the health state of the current battery, so that the charging state of the current battery is adapted to the health state of the current battery. The application constructs active safety management and control based on charging parameters, so that the battery is always charged under safe conditions that are adapted to the current health degree of the battery in the whole life cycle, and the risk is reduced.

Description

Technical Field

[0001] This application relates to the field of battery equipment technology, and more particularly to charging circuits and battery equipment. Background Technology

[0002] With the widespread use of batteries in various products such as consumer electronics, electric vehicles, and energy storage systems, their safety issues are becoming increasingly prominent. Accidents such as fires and explosions caused by thermal runaway occur frequently, seriously threatening the personal and property safety of users and drawing widespread attention from all sectors of society.

[0003] Currently, mainstream battery charging safety protection schemes are still primarily based on "post-event response." For example, they rely on fuses to blow in the event of abnormally high current, or on the battery management system to cut off the circuit after detecting obvious abnormal signals such as overvoltage or overcurrent. However, these protection strategies are usually only triggered when the battery has already experienced significant failure, or even is close to the thermal runaway threshold, resulting in a significant response lag. This causes the battery system to be exposed to potential safety risks throughout the entire charging cycle, which not only limits further improvements in battery life but also fails to provide users with continuous and reliable safety assurance.

[0004] The above content is only used to help understand the technical solution of this application and does not represent an admission that the above content is prior art. Summary of the Invention

[0005] The main purpose of this application is to provide a charging circuit that aims to solve the problems of slow response and high safety risks in existing battery charging protection schemes.

[0006] To achieve the above objectives, the charging circuit proposed in this application includes a switching power supply module, a fuel gauge module, and a main control module; The controlled terminal of the switching power supply module is connected to the first signal output terminal of the main control module, and the power output terminal of the switching power supply module is used to connect to the battery; the switching power supply module is used to convert the input external power into charging power and output it to the battery. The fuel gauge module is connected in series between the battery and the switching power supply module. The voltage sampling terminal of the fuel gauge module is connected to the voltage detection terminal of the battery, and the signal output terminal of the fuel gauge module is connected to the signal input terminal of the main control module. The fuel gauge module is used to detect the charging parameters of the battery during the charging process and output the corresponding charging parameter detection signal to the main control module. The main control module is used to determine the current battery charging parameters based on the charging parameter detection signal, determine the current battery health status based on the current battery charging parameters and the pre-stored battery factory charging parameters, and control the operation of the switching power supply module based on the current battery health status, so that the current battery charging status is compatible with the current battery health status.

[0007] In one embodiment, the charging parameter detection signal includes a first charging parameter detection signal, which is used to indicate the change of battery voltage with charging time. The pre-stored battery factory charging parameters include the preset voltage change slope of the battery at different charging power levels and different charging times; determining the current battery charging parameters based on the charging parameter detection signal, and determining the current battery health status based on the current battery charging parameters and the pre-stored battery factory charging parameters include: Based on the first charging parameter detection signal, the first voltage change slope of the current battery voltage as a function of charging time is calculated. The current charging power level of the battery is detected, and based on the current charging power level of the battery and the pre-stored battery factory charging parameters, a preset voltage change slope of the battery at the same charging power level and the same charging time is determined. The first health status coefficient of the current battery is determined based on the ratio of the first voltage change slope to the preset voltage change slope.

[0008] In one embodiment, the charging parameter detection signal includes a second charging parameter detection signal, which is used to indicate the actual charge amount of the battery at different charging times; The pre-stored battery factory charging parameters include the preset charging amount of the battery at different charging power levels and different charging times. The step of determining the current battery charging parameters based on the charging parameter detection signal, and determining the current battery health status based on the current battery charging parameters and the pre-stored battery factory charging parameters, includes: Based on the second charging parameter detection signal, the actual charging amount of the battery during the preset charging time period is calculated; The current charging power level of the battery is detected, and based on the current charging power level of the battery and the pre-stored battery factory charging parameters, the preset charging amount of the battery during the preset charging time period at the same charging power level is determined. The second health state coefficient of the current battery is determined based on the actual charging amount and the preset charging amount.

[0009] In one embodiment, the pre-stored battery factory charging parameters include the preset maximum charging cut-off voltage of the battery at the factory. The step of adjusting the operating parameters of the switching power supply module according to the current battery health state, so that the current battery charging state is adapted to the current battery health state, includes: The safe charging cut-off voltage of the current battery is calculated based on the first health state coefficient of the current battery and the preset maximum charging cut-off voltage. When the current battery voltage is detected to have reached the safe charging cutoff voltage, the switching power supply module is controlled to stop charging the battery, so that the maximum voltage of the current battery does not exceed the safe charging cutoff voltage of the current battery.

[0010] In one embodiment, the pre-stored battery factory charging parameters include the preset maximum charging rate of the battery at the factory; adjusting the operating parameters of the switching power supply module according to the current battery health state to adapt the current battery charging state to the current battery health state includes: The safe charging rate of the current battery is calculated based on the second health state coefficient of the current battery and the preset maximum charging rate. The operation of the switching power supply module is controlled based on the current safe charging rate of the battery, so that the maximum charging rate of the current battery does not exceed the current safe charging rate of the battery.

[0011] In one embodiment, the switching power supply module includes an H-bridge circuit and an energy storage inductor, wherein the energy storage inductor is connected between the midpoint of the left arm of the H-bridge circuit and the midpoint of the right arm of the H-bridge circuit. The step of controlling the operation of the switching power supply module according to the current battery health state, so that the current battery charging state is adapted to the current battery health state, includes: Based on the current health status of the battery, determine the drive signal parameters of multiple switching transistors in the H-bridge circuit, wherein the drive signal parameters include at least the on-duty cycle; Based on the drive signal parameters of the multiple switching transistors, multiple drive signals are output to control the operation of the H-bridge circuit, so that the current charging state of the battery matches the current health state of the battery.

[0012] In one embodiment, the fuel gauge module includes a sampling resistor and a fuel gauge chip; The sampling resistor is connected in series between the battery and the switching power supply module; The fuel gauge chip has a first differential detection pin group and a voltage detection pin. The two pins of the first differential detection pin group are respectively connected to the two ends of the sampling resistor to detect the differential voltage across the sampling resistor to determine the charging current. The voltage detection pin of the fuel gauge chip is the voltage sampling terminal of the fuel gauge module and is used to detect the voltage of the battery.

[0013] In one embodiment, the fuel gauge module further includes: A first switching circuit is connected in series between the switching power supply module and the battery, and is used to connect or disconnect the circuit between the switching power supply module and the battery; The fuel gauge chip also has a protection drive pin, which is connected to the controlled terminal of the first switching circuit. The fuel gauge chip is also used to control the operation of the first switching circuit according to the charging current and / or the voltage of the battery.

[0014] In one embodiment, the charging circuit further includes: A protection circuit, connected in series between the switching power supply module and the battery, is used to connect or disconnect the circuit between the switching power supply module and the battery; The controlled terminal of the protection circuit is connected to the second signal output terminal of the main control module. The main control module is also used to control the operation of the protection circuit according to the current health status of the battery or an external trigger command.

[0015] This application also proposes a battery device, including a battery and a charging circuit as described above.

[0016] This application employs a charging circuit comprising a switching power supply module, a fuel gauge module, and a main control module. When the charging circuit charges the battery, the main control module starts and initializes, reading pre-stored factory charging parameters of the battery as a reference. The switching power supply module connects to an external power source and operates under controlled conditions, converting the input power into charging power output to the battery. Simultaneously, the fuel gauge module collects charging parameters such as battery voltage and actual charge amount per unit time, transmitting these parameters to the main control module as charging parameter detection signals. Subsequently, the main control module determines the current battery voltage, actual charge amount per unit time, and other charging parameters based on the received charging parameter detection signals, comparing and analyzing them with the pre-stored factory parameters to determine the battery's current health status. Finally, the main control module controls the operation of the switching power supply module according to the current battery health status, ensuring that the current battery charging state matches the current battery health status. For example, the worse the battery health status, the lower the maximum charging cutoff voltage and / or the lower the maximum charging rate is set to charge the battery, thereby ensuring that the battery is charged in a safe charging state matching its health level from the moment it leaves the factory. Thus, this application constructs an active safety management mechanism based on battery charging parameters by continuously assessing the battery health status throughout the entire charging cycle. This eliminates the hysteresis defect of existing solutions that only trigger protection when there is overvoltage, overcurrent, or near thermal runaway. It ensures that the battery is always charged under safe conditions that are compatible with its current health status throughout its entire life cycle. This reduces safety risks, effectively avoids the risk of cumulative damage, and extends the battery's service life. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application 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 this application. 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 A schematic diagram of the structure of an embodiment of the charging circuit provided in this application; Figure 2 A schematic diagram of another embodiment of the charging circuit provided in this application; Figure 3 An electronic circuit diagram of a switching power supply module according to an embodiment of the charging circuit provided in this application; Figure 4 Electronic circuit diagram of a fuel gauge module and a main control module according to an embodiment of the charging circuit provided in this application.

[0019] Explanation of icon numbers: 10. Switching power supply module; 20. Fuel meter module; 30. Main control module; 40. Protection circuit; 21. First switching circuit; U5. Fuel meter chip; R90. Sampling resistor; L3. Energy storage inductor.

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

[0021] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0022] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0023] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed in this application.

[0024] Currently, mainstream battery charging safety protection schemes are still primarily based on "post-event response." For example, they rely on fuses to blow in the event of abnormally high current, or on the battery management system to cut off the circuit after detecting obvious abnormal signals such as overvoltage or overcurrent. However, these protection strategies are usually only triggered when the battery has already experienced significant failure, or even is close to the thermal runaway threshold, resulting in a significant response lag. This causes the battery system to be exposed to potential safety risks throughout the entire charging cycle, which not only limits further improvements in battery life but also fails to provide users with continuous and reliable safety assurance.

[0025] This application proposes a charging circuit.

[0026] Please see Figure 1In one embodiment of this application, the charging circuit includes a switching power supply module 10, a fuel meter module 20, and a main control module 30. The controlled terminal of the switching power supply module 10 is connected to the first signal output terminal of the main control module 30, and the power output terminal of the switching power supply module 10 is used to connect to the battery; the switching power supply module 10 is used to convert the input external power into charging power and output it to the battery. The fuel gauge module 20 is connected in series between the battery and the switching power supply module 10. The voltage sampling terminal of the fuel gauge module 20 is connected to the voltage detection terminal of the battery, and the signal output terminal of the fuel gauge module 20 is connected to the signal input terminal of the main control module 30. The fuel gauge module 20 is used to detect the charging parameters of the battery during the charging process and output the corresponding charging parameter detection signal to the main control module 30. The main control module 30 is used to determine the current battery charging parameters based on the charging parameter detection signal, determine the current battery health status based on the current battery charging parameters and the pre-stored battery factory charging parameters, and control the operation of the switching power supply module 10 based on the current battery health status, so that the current battery charging status is compatible with the current battery health status.

[0027] In this embodiment, the charging circuit includes a switching power supply module 10, a fuel gauge module 20, and a main control module 30. The switching power supply module 10 can employ a DC / DC converter to convert the input external power supply into a charging power supply for the battery. The fuel gauge module 20 may include a fuel gauge chip U5 and a current sampling resistor. The current sampling resistor is connected in series in the charging circuit. The fuel gauge chip U5 is configured to collect the differential voltage across the current sampling resistor to determine the charging current, and is connected to the battery's voltage detection terminal via a voltage sampling terminal to detect the battery's terminal voltage. The main control module 30 may include an MCU chip and a non-volatile memory. The non-volatile memory stores the battery's factory charging parameters and supports recording charging parameters throughout its entire lifespan. The MCU chip is configured to determine the current battery health status based on the current battery charging parameters collected by the fuel gauge module 20 and the pre-stored battery factory charging parameters, and control the operation of the switching power supply module 10 to ensure that the current battery charging state matches the current battery health state.

[0028] It should be noted that this embodiment monitors the battery status from the moment the battery leaves the factory. For example, it monitors the integral of the charge over time and the change in the slope of the battery terminal voltage. Based on real-time data, it determines the real-time health status of the battery and executes corresponding control measures according to the real-time health status. For example, when it is detected that the current battery has aged to a certain extent, the maximum charging cut-off voltage and the maximum charging rate during battery charging can be reduced to achieve safe control of the battery throughout its entire life cycle and reduce safety risks.

[0029] It should be noted that during charging, a healthy battery can efficiently accept charging current and convert it into chemical energy for storage; however, an aged battery, limited by the loss of active lithium or capacity decay, has a significantly lower charge acceptance capacity than the factory standard, manifested as a faster voltage rise (larger voltage change slope) within the same time period, and the actual charging amount within the same time period is less than the factory value. Based on this, this embodiment can quantify the "attenuation of the actual charging amount within the same preset time period relative to the factory standard" and the "increase of the voltage change slope at the same power and charging time relative to the factory standard" to deduce the current health status of the battery, and adaptively adjust the maximum charging cut-off voltage and maximum charging rate accordingly. In this way, it ensures that the charging operation of the battery is always matched with the actual load-bearing capacity of the battery, thereby constructing an active safety protection mechanism that covers the entire battery life cycle and avoids the risk of thermal runaway from the source.

[0030] In this embodiment, when the charging circuit charges the battery, the main control module 30 starts and initializes, reading the pre-stored factory charging parameters of the battery as a reference. The switching power supply module 10 is connected to an external power source and operates in a controlled state, converting the input power into charging power output to the battery. Simultaneously, the fuel gauge module 20 collects charging parameters such as the battery voltage and the actual charging amount per unit time, and transmits these charging parameters to the main control module 30 as charging parameter detection signals. Subsequently, the main control module 30 determines the current battery voltage, actual charging amount per unit time, and other charging parameters based on the received charging parameter detection signals, and compares and analyzes them with the pre-stored factory parameters to determine the current health status of the battery. Finally, the main control module 30 controls the operation of the switching power supply module 10 according to the current battery health status, ensuring that the current battery charging state matches the current battery health status. For example, the worse the battery health status, the lower the maximum charging cutoff voltage and / or the lower the maximum charging rate is set to charge the battery, thereby ensuring that the battery is charged in a safe charging state that matches its health level from the moment it leaves the factory. Thus, this embodiment achieves charging safety throughout the battery's entire life cycle. Compared with existing technologies, this embodiment constructs an active safety management mechanism based on battery charging parameters by continuously evaluating the battery health status throughout the entire charging cycle. This eliminates the hysteresis defect of existing solutions that only trigger protection when there is overvoltage, overcurrent, or near thermal runaway. It ensures that the battery is always charged under safe conditions that are adapted to its current health status throughout its entire life cycle. This reduces safety risks, effectively avoids the risk of cumulative damage, and extends the battery's service life.

[0031] In one embodiment of this application, the charging parameter detection signal includes a first charging parameter detection signal, which is used to indicate the change of battery voltage with charging time. The pre-stored battery factory charging parameters include the preset voltage change slope of the battery at different charging power levels and charging times; the current battery charging parameters are determined based on the charging parameter detection signal, and the current battery health status is determined based on the current battery charging parameters and the pre-stored battery factory charging parameters, including: Based on the first charging parameter detection signal, the first voltage change slope of the current battery voltage as a function of charging time is calculated. Obtain the current charging power level of the battery, and based on the current charging power level of the battery and the pre-stored battery factory charging parameters, determine the preset voltage change slope of the battery at the same charging power level and the same charging time. The first health state coefficient of the current battery is determined based on the ratio of the first voltage change slope to the preset voltage change slope.

[0032] It should be noted that the main control module can obtain the current battery charging power level through the charger connected to the charging circuit, or through a user-triggered command; there are no restrictions here.

[0033] In this embodiment, the fuel gauge module 20 detects the change curve of the battery terminal voltage with charging time in real time at a preset sampling rate frequency (e.g., once per second), and outputs a first charging parameter detection signal containing a timestamp and voltage value. After receiving this signal, the main control module 30 selects a time window of the current charging stage (e.g., 1 minute after the SOC reaches 10%), and calculates the first voltage change slope of the voltage change with time during this time period using linear regression or differential algorithms. This slope intuitively reflects the internal resistance characteristics and polarization degree of the battery in the current charging state. The main control module 30 simultaneously detects the current charging power level (e.g., 10W, 18W, or fast charging level), and combines it with the current charging time period (1 minute after the SOC reaches 10%), retrieves the benchmark data that perfectly matches the power level and time period (1 minute after the SOC reaches 10%) from the pre-stored battery factory charging parameter library, and extracts the preset voltage change slope that the factory battery should have under the same operating conditions. This step ensures the accuracy of the comparison benchmark and eliminates the natural voltage fluctuation differences caused by different charging powers or different SOC ranges. The main control module 30 compares the measured first voltage change slope with the preset voltage change slope, calculates the ratio between the two, and thus determines the first health state coefficient. If the battery is healthy, the measured slope should be close to the preset slope (the ratio approaches 1); if battery aging leads to increased internal resistance, the measured slope will be significantly greater than the preset slope (the ratio is significantly greater than 1), and the health state coefficient will decrease accordingly, indicating a decline in battery health. For example, at the 18W fast charging level, when the battery charge is in the 10% to 20% range, the factory-set voltage rise characteristic of the battery is stable, and the factory-preset voltage change slope is 0.04 V / min (i.e., the voltage rises by 0.04 volts per minute). The fuel gauge module 20 detects that within the current 10% to 20% charging range, the battery voltage rapidly rises from 3.65V to 3.77V within 1 minute. The main control module 30 calculates the current first voltage change slope as 0.12V / min based on the collected data. The main control module 30 identifies that the current charging mode is "18W" and that it is "one minute after the SOC reaches 10%". It then retrieves the corresponding preset voltage change slope from memory, for example, 0.10V / min. The main control module 30 calculates the ratio of these two values ​​to be 1.2. The first health coefficient can be the reciprocal of 1.2, which is 0.83. Similarly, the first preset voltage change slope can be calculated one minute after the SOC reaches 20%, one minute after the SOC reaches 30%, or even longer charging periods during a single charge, thereby determining the current battery's first health state coefficient. No limitation is imposed here. Thus, this embodiment can continuously update the first health state coefficient during each battery charge, ensuring that the current battery charging state always matches the first health state coefficient.

[0034] In one embodiment of this application, the charging parameter detection signal includes a second charging parameter detection signal, which is used to indicate the actual amount of charge of the battery at different charging times. The pre-stored battery factory charging parameters include the preset charging amount of the battery at different charging power levels and different charging times. The charging parameters of the current battery are determined based on the charging parameter detection signal. The current battery health status is then determined based on the current charging parameters and the pre-stored factory charging parameters, including: The actual charge amount of the battery during the preset charging time period is calculated based on the second charging parameter detection signal. Obtain the current charging power level of the battery, and based on the current charging power level of the battery and the pre-stored battery factory charging parameters, determine the preset charging amount of the battery during the preset charging time period at the same charging power level. The second health state coefficient of the current battery is determined based on the actual charging amount and the preset charging amount.

[0035] In this embodiment, the fuel gauge module 20 detects the charging current and performs integration calculations at a preset sampling rate frequency (e.g., once per second) to detect the change curve of the charged capacity over charging time, and outputs a second charging parameter detection signal containing a timestamp and the charging amount. After receiving this signal, the main control module 30 determines the actual charging amount of the battery within a preset charging time period, such as the actual charge absorbed in one minute after the SOC reaches 10%. The main control module 30 simultaneously detects the current charging power level (e.g., 10W, 18W, or fast charging) and, combined with the preset charging time period (one minute after the SOC reaches 10%), retrieves benchmark data from the pre-stored battery factory charging parameter library that perfectly matches the power level and time period (one minute after the SOC reaches 10%), extracting the preset charging amount that the factory-manufactured battery should have under the same operating conditions. This ensures the accuracy of the comparison benchmark and eliminates differences in charging amount fluctuations caused by different charging powers or different SOC ranges. The main control module 30 compares the actual charging amount with the preset charging amount, calculates the ratio between the two, and thus determines the second health state coefficient. If the battery is healthy, the measured slope should be close to the preset slope (the ratio should be close to 1). If battery aging leads to increased internal resistance, the measured slope will be significantly greater than the preset slope (the ratio should be significantly less than 1). In this case, the health status coefficient will decrease accordingly, indicating a decline in battery health. For example, in 18W fast charging mode, when the battery is in the first minute after reaching 10% SOC, the factory-installed battery, due to its low internal resistance and low polarization, can maintain high-current charging. The factory-preset cumulative charging amount in this minute is 180 mAh (i.e., an average current of approximately 180 mA·min). When the user connects the charger, the charging circuit operates at 18W. The fuel gauge module 20 detects and integrates the current in real time, calculating the actual charge absorbed by the battery in the first minute after reaching 10% SOC. If the battery is aged, limited by the loss of active lithium, the fuel gauge module 20 detects that the actual charging amount in the first minute after reaching 10% SOC is only 144 mAh. The main control module 30 identifies the current operating condition as "18W level" and is within the "1 minute after SOC reaches 10%" window, retrieving the corresponding preset charging amount of 180 mAh from the memory. The main control module 30 calculates the ratio between the two to be 0.8 and directly maps this ratio of 0.8 to the second health state coefficient. This indicates that the current battery's charging acceptance capacity is only 80% of that of a new battery, directly reflecting the decline in battery health. Similarly, the preset time period can also be 1 minute after SOC reaches 20%, 1 minute after SOC reaches 30%, or even more charging time periods during a single charge. The actual charging amount for multiple preset time periods can also be calculated to determine the current battery's second health state coefficient; no limitations are imposed here. Thus, this embodiment can continuously update the second health state coefficient with each charge, ensuring that the current battery charging state always matches the second health state coefficient.

[0036] It should be noted that as batteries age, their internal resistance increases and polarization intensifies. If they are still charged at the maximum charging cutoff voltage of a new battery, the actual electrochemical potential inside the battery may have already exceeded the safety threshold, which can easily lead to lithium plating or electrolyte decomposition, resulting in the risk of thermal runaway.

[0037] In one embodiment of this application, the pre-stored battery factory charging parameters include the preset maximum charging cut-off voltage of the battery at the factory. Adjusting the operating parameters of the switching power supply module 10 according to the current battery health status to adapt the current battery charging state to the current battery health status includes: The safe charging cut-off voltage of the current battery is calculated based on the current battery's first state of health coefficient and the preset maximum charging cut-off voltage. When the current battery voltage is detected to have reached the safe charging cutoff voltage, the control switching power supply module 10 stops charging the battery, so that the maximum voltage of the current battery does not exceed the safe charging cutoff voltage of the current battery.

[0038] In this embodiment, the safe charging cut-off voltage can be linearly reduced according to the battery's aging level. Specifically, the safe charging cut-off voltage can be the product of a first health state coefficient and a preset maximum charging cut-off voltage. During battery charging, the main control module 30 detects the battery voltage through the fuel gauge module 20. When the battery voltage reaches the safe charging cut-off voltage, the main control module 30 determines that the battery has reached its physical safety limit under its current health state and controls the switching power supply module 10 to stop charging the battery or reduce the charging current to a trickle state close to zero. This embodiment prevents the risk of bulging, overheating, or even fire caused by overcharging, and extends the remaining battery life.

[0039] It should be noted that as the battery ages, its internal resistance increases, and the Joule heat generated by charging at high rates will increase significantly, which can easily exacerbate polarization reactions.

[0040] In one embodiment of this application, the pre-stored battery factory charging parameters include the preset maximum charging rate of the battery at the factory; adjusting the operating parameters of the switching power supply module 10 according to the current battery health state to adapt the current battery charging state to the current battery health state includes: The safe charging rate of the current battery is calculated based on the current battery's second state of health coefficient and the preset maximum charging rate. The operation of the switching power supply module 10 is controlled based on the current safe charging rate of the battery, so that the maximum charging rate of the current battery does not exceed the current safe charging rate of the battery.

[0041] In this embodiment, the safe charging rate can be linearly reduced according to the battery's aging level. Specifically, the safe charging rate can be the product of a second health state coefficient and a preset maximum charging rate. During battery charging, the main control module 30 can obtain the charging current and current full charge capacity of the charging circuit through the internal register of the fuel gauge module 20, and calculate the current charging rate based on the ratio of the two. When it is detected that the battery's charging rate attempts to exceed the battery's safe charging rate, the duty cycle of the switching power supply is immediately adjusted to force the battery's charging rate to be clamped below the safe charging rate, ensuring that the battery is always charged within the safe current range. Thus, this embodiment avoids charging the battery at a large current exceeding the safe charging rate, extending the battery's lifespan.

[0042] Please see Figure 3 In one embodiment of this application, the switching power supply module 10 includes an H-bridge circuit and an energy storage inductor L3, with the energy storage inductor L3 connected between the midpoint of the left arm of the H-bridge circuit and the midpoint of the right arm of the H-bridge circuit. Controlling the operation of the switching power supply module 10 according to the current battery health state, so that the current battery charging state is adapted to the current battery health state, includes: Based on the current health status of the battery, determine the drive signal parameters of multiple switching transistors in the H-bridge circuit. The drive signal parameters include at least the on-duty cycle. Based on the drive signal parameters of multiple switching transistors, multiple drive signals are output to control the operation of the H-bridge circuit, so that the current battery charging state matches the current battery health state.

[0043] In this embodiment, the H-bridge circuit includes four switching transistors (Q4, Q5, Q7, Q8). An energy storage inductor L3 is connected between the midpoint of the left arm (Q4, Q7) and the midpoint of the right arm (Q5, Q8) of the H-bridge circuit. The main control module 30 outputs four pulse width modulation signals according to the current health status of the battery, and dynamically adjusts the duty cycle of the four switching transistors to control the switching power supply module 10 to charge the current battery according to the condition of not exceeding the safe charging cutoff voltage and / or safe charging rate. During the energy transfer phase, Q4 and Q8 are turned on, while Q5 and Q7 are turned off. The current flows along the path VOUT2, Q4, L3, Q8 to GND. The current in the energy storage inductor L3 increases linearly and stores magnetic field energy, while simultaneously transferring energy to the P+ terminal. During the freewheeling phase, Q5 and Q7 are turned on, while Q4 and Q8 are turned off, forming a freewheeling loop. The current flows along the path GND, Q7, L3, Q5 to P+, and the induced electromotive force of L3 continues to release energy to the P+ terminal. It should be noted that the drive signal parameters may also include the phase difference between the left and right bridge arm switches. Specifically, in charging mode, the main control module 30 may also employ a phase-shift control strategy: During the energy transfer phase, by adjusting the phase difference between the left bridge arm (Q4 / Q7) and right bridge arm (Q5 / Q8) switch signals, the overlap time of simultaneous conduction of Q4 and Q8 is controlled, allowing the current to flow along the path from VOUT2, Q4, L3, Q8 to GND. The current in the energy storage inductor L3 increases linearly and stores magnetic field energy, while simultaneously transferring energy to the P+ terminal. During the freewheeling phase, the phase difference decreases or disappears, Q5 and Q7 conduct to form a freewheeling loop, and the current flows along the path from GND, Q7, L3, Q5 to P+, utilizing the induced electromotive force of L3 to continue releasing energy to the P+ terminal. In this process, the main control module 30 adjusts the duty cycle of energy transfer by increasing or decreasing the phase-shifting phase angle, thereby precisely controlling the charging current and ensuring the safety and reliability of the charging process.

[0044] Please see Figure 4 In one embodiment of this application, the fuel meter module 20 includes a sampling resistor R90 and a fuel meter chip U5; The sampling resistor R90 is connected in series between the battery and the switching power supply module 10; The fuel gauge chip U5 has a first differential detection pin group and a voltage detection pin. The two pins of the first differential detection pin group are respectively connected to the two ends of the sampling resistor R90 to detect the differential voltage across the sampling resistor R90 to determine the charging current. The voltage detection pin of the fuel gauge chip U5 is the voltage sampling terminal of the fuel gauge module 20 and is used to detect the battery voltage.

[0045] The fuel gauge module 20 also includes: The first switching circuit 21 is connected in series between the switching power supply module 10 and the battery, and is used to connect or disconnect the circuit between the switching power supply module 10 and the battery. The fuel gauge chip U5 also has a protection drive pin, which is connected to the controlled terminal of the first switching circuit 21. The fuel gauge chip U5 is also used to control the operation of the first switching circuit 21 according to the charging current and / or the battery voltage.

[0046] In this embodiment, during charging or discharging, current flows through the sampling resistor R90, generating a voltage drop. The fuel gauge chip U5 reads this voltage drop through the SRP / SRN differential pin and calculates the instantaneous charging current value according to Ohm's law. Thus, the fuel gauge chip U5 can calculate the actual charge amount of the battery during the current charging period based on the instantaneous charging current value and its internal coulomb counter. Furthermore, the fuel gauge chip U5 internally calculates the battery's full-charge capacity using the coulomb integration method, accumulating and integrating the inflow and outflow of charge during each complete charge-discharge cycle. When the battery reaches a fully charged state (meeting the safe charging cutoff voltage condition), the fuel gauge chip U5 automatically updates its internal full-charge capacity register to reflect the actual capacity changes with aging. Simultaneously, the fuel gauge chip U5 obtains the current battery terminal voltage through the voltage detection pin VC1. The fuel gauge chip U5 communicates with the main control module 30 via I2C through the SMBC and SMBD pins, sending a first charging parameter detection signal and a second charging parameter detection signal. Meanwhile, the fuel gauge chip U5 can also obtain the updated safe charging cutoff voltage from the main control module 30 to update the internal full charge capacity register when the battery reaches the updated safe charging cutoff voltage.

[0047] In this embodiment, the first switching circuit 21 includes a charging switch transistor Q15. The fuel gauge chip U5 also presets safety thresholds (such as overcurrent and overvoltage thresholds). During charging, the instantaneous charging current value is compared with the overcurrent threshold, and the battery voltage is compared with the overvoltage threshold. When both the detected charging current and battery voltage are within safe limits, the fuel gauge chip U5 outputs a high level through the protection drive pin CHG to control the charging switch transistor Q15 to conduct, thus opening the charging circuit. When the detected charging current value exceeds the overcurrent threshold or the battery voltage exceeds the overvoltage threshold, the protection drive pin CHG outputs a low level to control the charging switch transistor Q15 to turn off, thus disconnecting the charging circuit. It is understood that in the charging and discharging circuit, the first switching circuit 21 may also include a discharging switch transistor Q12 to control the conduction / discharge of the discharging circuit. It is also understood that the main control circuit can establish a communication connection with the fuel gauge module 20 via I2C, thereby controlling the conduction / discharge between the battery and the switching power supply module 10 through the fuel gauge module 20; this is not limited here. Thus, this embodiment can accurately collect charging current and battery voltage, improving detection accuracy, and can realize battery charging control, as well as overcurrent and overvoltage protection, ensuring strong safety.

[0048] Please see Figure 2 and Figure 4 In one embodiment of this application, the charging circuit further includes: Protection circuit 40 is connected in series between the switching power supply module 10 and the battery, and is used to connect or disconnect the circuit between the switching power supply module 10 and the battery. The controlled terminal of the protection circuit 40 is connected to the second signal output terminal of the main control module 30. The main control module 30 is also used to control the operation of the protection circuit 40 according to the current health status of the battery or external trigger commands.

[0049] In this embodiment, the protection circuit 40 includes a fusible protection element and a controllable discharge branch. The fusible protection element is connected in series in the charging circuit between the switching power supply module 10 and the battery, configured to disconnect the charging circuit when the current flowing through it exceeds a preset fusing threshold. One end of the controllable discharge branch is connected to the fusible protection element, and the other end is grounded. The second signal output terminal of the main control module 30 is connected to the controlled terminal EN of the controllable discharge branch and is configured to output a control signal to the controllable discharge branch when the battery's current health status is determined to be below a minimum health status limit, or when an external stop charging command is received. In response to the control signal, the controllable discharge branch switches from a cutoff state to a conduction state to generate an overcurrent pulse in the main charging circuit, forcing the fusible protection element to disconnect due to the current exceeding the preset fusing threshold, thereby cutting off the charging circuit. The fusible protection element can be implemented using a resettable fuse F1, and the controllable discharge branch can be implemented using a switching transistor Q16. Thus, this embodiment not only provides passive protection during normal overcurrent, but also actively controls disconnection under potential risks such as deep deterioration of battery health or abnormal environment (e.g., detecting excessively high ambient temperature), effectively preventing the risk of battery thermal runaway and improving the safety of the charging circuit.

[0050] This application also proposes a battery device, which includes a charging circuit. The specific structure of the charging circuit is as described in the above embodiments. Since this battery device adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0051] The battery device can also be used to discharge, providing power to external devices. The switching power supply module 10 of the charging circuit can also be used to convert the battery power into the power output required by the external devices. The fuel gauge module 20 can also be used to collect the discharge parameters of the battery during the discharge process. The main control module 30 can also control the discharge of the battery by the switching power supply module 10 according to the current health status of the battery, such as limiting the maximum discharge current, etc., which are not limited here.

[0052] The above description is merely an exemplary embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made based on the technical concept of this application and the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A charging circuit, characterized in that, Includes a switching power supply module, a fuel gauge module, and a main control module; The controlled terminal of the switching power supply module is connected to the first signal output terminal of the main control module, and the power output terminal of the switching power supply module is used to connect to the battery; the switching power supply module is used to convert the input external power into charging power and output it to the battery. The fuel gauge module is connected in series between the battery and the switching power supply module. The voltage sampling terminal of the fuel gauge module is connected to the voltage detection terminal of the battery, and the signal output terminal of the fuel gauge module is connected to the signal input terminal of the main control module. The fuel gauge module is used to detect the charging parameters of the battery during the charging process and output the corresponding charging parameter detection signal to the main control module. The main control module is used to determine the current battery charging parameters based on the charging parameter detection signal, determine the current battery health status based on the current battery charging parameters and the pre-stored battery factory charging parameters, and control the operation of the switching power supply module based on the current battery health status, so that the current battery charging status is compatible with the current battery health status.

2. The charging circuit as described in claim 1, characterized in that, The charging parameter detection signal includes a first charging parameter detection signal, which is used to indicate the change of battery voltage with charging time. The pre-stored battery factory charging parameters include the preset voltage change slope of the battery at different charging power levels and different charging times; determining the current battery charging parameters based on the charging parameter detection signal, and determining the current battery health status based on the current battery charging parameters and the pre-stored battery factory charging parameters include: Based on the first charging parameter detection signal, the first voltage change slope of the current battery voltage as a function of charging time is calculated. The current charging power level of the battery is detected, and based on the current charging power level of the battery and the pre-stored battery factory charging parameters, a preset voltage change slope of the battery at the same charging power level and the same charging time is determined. The first health status coefficient of the current battery is determined based on the ratio of the first voltage change slope to the preset voltage change slope.

3. The charging circuit as described in claim 1, characterized in that, The charging parameter detection signal includes a second charging parameter detection signal, which is used to indicate the actual amount of charge the battery receives at different charging times. The pre-stored battery factory charging parameters include the preset charging amount of the battery at different charging power levels and different charging times. The step of determining the current battery charging parameters based on the charging parameter detection signal, and determining the current battery health status based on the current battery charging parameters and the pre-stored battery factory charging parameters, includes: The actual charge amount of the battery during the preset charging time period is calculated based on the second charging parameter detection signal. The current charging power level of the battery is detected, and based on the current charging power level of the battery and the pre-stored battery factory charging parameters, the preset charging amount of the battery during the preset charging time period at the same charging power level is determined. The second health state coefficient of the current battery is determined based on the actual charging amount and the preset charging amount.

4. The charging circuit as described in claim 2, characterized in that, The pre-stored battery factory charging parameters include the preset maximum charging cut-off voltage of the battery. The step of adjusting the operating parameters of the switching power supply module according to the current battery health state, so that the current battery charging state is adapted to the current battery health state, includes: The safe charging cut-off voltage of the current battery is calculated based on the first health state coefficient of the current battery and the preset maximum charging cut-off voltage. When the current battery voltage is detected to have reached the safe charging cutoff voltage, the switching power supply module is controlled to stop charging the battery, so that the maximum voltage of the current battery does not exceed the safe charging cutoff voltage of the current battery.

5. The charging circuit as described in claim 3, characterized in that, The pre-stored battery factory charging parameters include the preset maximum charging rate of the battery; adjusting the operating parameters of the switching power supply module according to the current battery health status to adapt the current battery charging status to the current battery health status includes: The safe charging rate of the current battery is calculated based on the second health state coefficient of the current battery and the preset maximum charging rate. The operation of the switching power supply module is controlled based on the current safe charging rate of the battery, so that the maximum charging rate of the current battery does not exceed the current safe charging rate of the battery.

6. The charging circuit as described in claim 1, characterized in that, The switching power supply module includes an H-bridge circuit and an energy storage inductor. The energy storage inductor is connected between the midpoint of the left arm of the H-bridge circuit and the midpoint of the right arm of the H-bridge circuit. The step of controlling the operation of the switching power supply module according to the current battery health state, so that the current battery charging state is adapted to the current battery health state, includes: Based on the current health status of the battery, determine the drive signal parameters of multiple switching transistors in the H-bridge circuit, wherein the drive signal parameters include at least the on-duty cycle; Based on the drive signal parameters of the multiple switching transistors, multiple drive signals are output to control the operation of the H-bridge circuit, so that the current charging state of the battery matches the current health state of the battery.

7. The charging circuit as described in claim 1, characterized in that, The fuel meter module includes a sampling resistor and a fuel meter chip; The sampling resistor is connected in series between the battery and the switching power supply module; The fuel gauge chip has a first differential detection pin group and a voltage detection pin. The two pins of the first differential detection pin group are respectively connected to the two ends of the sampling resistor to detect the differential voltage across the sampling resistor to determine the charging current. The voltage detection pin of the fuel gauge chip is the voltage sampling terminal of the fuel gauge module and is used to detect the voltage of the battery.

8. The charging circuit as described in claim 7, characterized in that, The fuel gauge module also includes: A first switching circuit is connected in series between the switching power supply module and the battery, and is used to connect or disconnect the circuit between the switching power supply module and the battery; The fuel gauge chip also has a protection drive pin, which is connected to the controlled terminal of the first switching circuit. The fuel gauge chip is also used to control the operation of the first switching circuit according to the charging current and / or the voltage of the battery.

9. The charging circuit as described in claim 1, characterized in that, Also includes: A protection circuit, connected in series between the switching power supply module and the battery, is used to connect or disconnect the circuit between the switching power supply module and the battery; The controlled terminal of the protection circuit is connected to the second signal output terminal of the main control module. The main control module is also used to control the operation of the protection circuit according to the current health status of the battery or an external trigger command.

10. A battery device, characterized in that, Includes a battery and a charging circuit as described in any one of claims 1 to 9.

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