Dual-cell detection circuit, method and electronic equipment

Abstract

The present application provides a dual-cell detection circuit, method and electronic device. In the dual-cell detection circuit, a controller and a control circuit are used to control the generation of a controllable current between the two cells, so that energy transfer occurs between the two cells, and then the controller is used to collect the voltage signals of the two cells and the current signals between the two cells, respectively, to obtain the impedance spectra of the two cells, and to detect the health status of the two cells. In addition, the dual-cell detection circuit uses the cells as current excitation sources, and can implement impedance spectrum testing of the two cells without the need for external equipment to provide current excitation sources, thereby reducing detection costs.

Description

Technical Field

[0001] The present application relates to the field of electronic technology, and in particular to a dual-cell detection circuit, method and electronic equipment. Background Art

[0002] In electronic devices, such as mobile phones and tablets, dual-cell batteries can be used as the power source of electronic devices to provide longer battery life and higher power output. Especially for some high-power consumption applications, such as high-definition video playback, game running and multi-tasking, the dual-cell solution can increase the use time of electronic devices and meet the needs of users' daily use.

[0003] However, current technology cannot detect the health of the two cells separately during the use of electronic devices, and therefore cannot determine the degree of aging of the two cells in a timely manner. Cell aging may lead to problems such as increased cell temperature, reduced cell capacity, and cell damage. If the health of the two cells cannot be effectively detected, potential problems with the cells may not be identified in a timely manner, which may have a negative impact on the user experience and the overall performance of the device. Summary of the invention

[0004] The present application provides a dual-cell detection circuit, method and electronic device, which solves the problem that the health status of two cells cannot be detected separately during the use of the electronic device.

[0005] In order to achieve the above objectives, this application adopts the following technical solutions:

[0006] In a first aspect, the present application provides a dual-cell detection circuit for detecting the impedance of a first cell and a second cell, the circuit comprising a controller, a control circuit, a MOS tube and a detection circuit; wherein the first end of the first cell is connected to the first end of the second cell through the MOS tube and the detection resistor, and the second end of the first cell and the second end of the second cell are grounded;

[0007] The output voltage of the first battery cell is different from that of the second battery cell. When the controller outputs a PWM signal to the control circuit, the control circuit outputs a driving signal to the MOS tube according to the PWM signal, controls the resistance value of the MOS tube, and generates a current between the first battery cell and the second battery cell; the controller can obtain the impedance of the first battery cell and the second battery cell respectively according to the voltage at both ends of the first battery cell and the voltage at both ends of the second battery cell, as well as the current flowing through the detection resistor between the first battery cell and the second battery cell. The above dual-cell detection circuit can measure the impedance of the two batteries at a specific frequency, and then obtain the impedance spectra of the two batteries, so as to detect the health status of the two batteries.

[0008] In addition, the dual-cell detection circuit uses the cell as a current excitation source, and can realize online impedance spectrum testing of the two cells without the need for external equipment to provide a current excitation source, thereby reducing the detection cost. By controlling the current generated between the two cells, energy transfer occurs between the two cells, and when there is a voltage difference between the two cells, the two cells can be balanced and controlled, so that the voltages of the two cells eventually tend to be equal.

[0009] In a possible implementation, the control circuit includes an amplifier, a first resistor, a second resistor, a third resistor, and a fourth resistor; the resistance values ​​of the first resistor, the second resistor, the third resistor, and the fourth resistor are equal;

[0010] The controller is respectively connected to two ends of the first battery cell and two ends of the second battery cell, and is connected to the negative input end of the amplifier through a first resistor; the positive input end of the amplifier is connected to the first end of the detection resistor through a fourth resistor, and is grounded through a third resistor; the negative input end of the amplifier is connected to the second end of the detection resistor; the output end of the amplifier is connected to the gate of the MOS tube; the positive electrode of the first battery cell is connected to the drain of the MOS tube, and the negative electrode of the first battery cell is grounded; the positive electrode of the second battery cell is connected to the first end of the detection resistor, and the negative electrode of the second battery cell is grounded; the second end of the detection resistor is connected to the source of the MOS tube.

[0011] The control circuit is a negative feedback circuit that can dynamically adjust the voltage across the MOS tube according to the PWM signal and the voltage across the detection circuit, thereby controlling the resistance value of the MOS tube and changing the voltage division size between the MOS tube and the detection resistor, so that the current between the first battery cell and the second battery cell changes with the change of the PWM signal.

[0012] The controller collects the voltage across the first battery cell, the voltage across the second battery cell, and the current between the first battery cell and the second battery cell; it can then determine the impedance of the first battery cell based on the voltage and current across the first battery cell, and determine the impedance of the second battery cell based on the voltage and current across the second battery cell, thereby realizing online detection of the impedances of the two battery cells.

[0013] In one possible implementation, the controller includes a first analog-to-digital converter, a second analog-to-digital converter and a pulse width modulation (PWM) module; the first analog-to-digital converter is connected to two ends of a first battery cell, and the second analog-to-digital converter is connected to two ends of a second battery cell; the PWM module is connected to the negative input terminal of the amplifier through a first resistor; the first analog-to-digital converter is used to collect the voltage across the first battery cell; the second analog-to-digital converter is used to collect the voltage across the second battery cell; the PWM module is used to generate a PWM signal according to a sinusoidal function modulation of a preset frequency, and output the PWM signal to the amplifier.

[0014] The voltages of the two cells are collected by the first analog-to-digital converter and the second analog-to-digital converter, and the collected signals are converted from analog signals to digital signals so that the controller can process, analyze and control them. By switching the frequency of the sine function, the PWM module can modulate the sine function of different frequencies to obtain the corresponding PWM signal, so that the controller can measure the impedance of the first cell and the second cell at different frequencies, and then detect the health status of the two cells respectively.

[0015] In a possible implementation, the dual-cell detection circuit further includes a first low-pass filter and a second low-pass filter;

[0016] The output end of the first low-pass filter is connected to the first analog-to-digital converter, and the input end of the first low-pass filter is connected to the two ends of the first battery cell. The first low-pass filter can perform low-pass filtering on the signal collected from the two ends of the first battery cell to filter out the influence of high-frequency noise signals on the voltage detection accuracy;

[0017] The output end of the second low-pass filter is connected to the second analog-to-digital converter, and the input end of the second low-pass filter is connected to the two ends of the second battery cell. The second low-pass filter can be used to perform low-pass filtering on the signals collected from the two ends of the second battery cell to filter out the influence of high-frequency noise signals on the voltage detection accuracy.

[0018] In a possible implementation, the dual-cell detection circuit further includes a third low-pass filter, and the controller further includes a third analog-to-digital converter;

[0019] The output end of the third low-pass filter is connected to the third analog-to-digital converter, and the input end of the third low-pass filter is connected to both ends of the detection resistor; the third analog-to-digital converter is used to collect the current flowing through the detection resistor, and convert the current in the form of an analog signal into a current in the form of a digital signal; the third low-pass filter is used to perform low-pass filtering on the signal collected from both ends of the detection resistor, so as to filter out the influence of high-frequency noise signals on the accuracy of current detection.

[0020] In a second aspect, the present application provides a dual-cell detection method, which is applied to a dual-cell detection circuit, wherein the dual-cell detection circuit includes a control circuit, a MOS tube and a detection resistor; the first end of the first cell is connected to the first end of the second cell through the MOS tube and the detection resistor, and the second end of the first cell is grounded to the second end of the second cell; the control circuit is used to output a drive signal to the MOS tube according to a pulse width modulation PWM signal input at the input end;

[0021] By controlling the voltage difference between the first battery cell and the second battery cell and outputting a PWM signal to the control circuit, a current is generated between the first battery cell and the second battery cell; then, the impedance of the first battery cell is determined according to the current flowing through the detection resistor and the voltage across the first battery cell, and the impedance of the second battery cell is determined according to the current of the detection resistor and the voltage across the second battery cell, the impedances of the two battery cells are obtained respectively, so as to detect the health status of each of the two battery cells separately.

[0022] In a possible implementation, a PWM signal can be obtained by modulating a sine function of a preset frequency. By changing the frequency of the sine function, a PWM signal of a corresponding frequency can be modulated, and the impedances of the two cells at different frequencies can be measured to obtain the impedance spectrum of the first cell and the impedance spectrum of the second cell, and then the health status of the two cells can be evaluated based on the impedance spectrum.

[0023] In a possible implementation, the impedances of the first battery cell and the second battery cell corresponding to the sine functions of each frequency are measured by switching multiple frequency sine functions and modulating multiple frequency PWM signals. The impedance spectrum of the first battery cell is obtained based on the multiple impedances of the first battery cell, and then the health status of the first battery cell is detected based on the impedance spectrum of the first battery cell; similarly, the impedance spectrum of the second battery cell is obtained based on the multiple impedances of the second battery cell, and the health status of the second battery cell is detected based on the impedance spectrum of the second battery cell, thereby realizing online detection of the health status of the two battery cells.

[0024] In a possible implementation, the first battery cell and the second battery cell can be charged simultaneously to make a voltage difference between the first battery cell and the second battery cell; or any one of the first battery cell and the second battery cell can be charged to make a voltage difference between the first battery cell and the second battery cell.

[0025] In a third aspect, the present application provides an electronic device, including a power management module, a first battery cell, and a second battery cell;

[0026] The power management module is used to control the current generated between the first battery cell and the second battery cell, and to collect the voltage across the first battery cell, the voltage across the second battery cell, and the current between the first battery cell and the second battery cell; the impedance of the first battery cell is determined according to the voltage and current across the first battery cell, and the impedance of the second battery cell is determined according to the voltage and current across the second battery cell.

[0027] In a fourth aspect, the present application provides a computer storage medium, comprising computer instructions, which, when executed on an electronic device, enables the electronic device to execute the method described in any one of the second aspects.

[0028] In a fifth aspect, the present application provides a computer program product, comprising instructions; when the instructions are executed by an electronic device, the electronic device executes the method described in any one of the second aspects.

[0029] It can be seen from the above technical solution that the present application has the following beneficial effects:

[0030] The present application provides a dual-cell detection circuit, method and electronic device. In the dual-cell detection circuit, a controller and a control circuit are used to control the generation of a controllable current between the two cells, so that energy transfer occurs between the two cells, and then the controller is used to collect the voltage signals of the two cells and the current signals between the two cells, respectively, to obtain the impedance spectrum of the two cells, and to detect the health status of the two cells. In addition, the dual-cell detection circuit uses the cells as a current excitation source, and can implement impedance spectrum testing of the two cells without the need for an external device to provide a current excitation source, thereby reducing the detection cost. By controlling the current generated between the two cells, energy transfer occurs between the two cells, and when there is a voltage difference between the two cells, the two cells can be balanced and controlled, so that the voltages of the two cells eventually tend to be equal. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A schematic diagram of an impedance spectrum provided in an embodiment of the present application;

[0032] Figure 2 Another impedance spectrum schematic diagram provided in an embodiment of the present application;

[0033] Figure 3 A schematic diagram of the structure of a dual-cell detection circuit provided in an embodiment of the present application;

[0034] Figure 4 A schematic diagram of the structure of another dual-cell detection circuit provided in an embodiment of the present application;

[0035] Figure 5A A schematic diagram of a voltage provided in an embodiment of the present application;

[0036] Figure 5B A schematic diagram of a current provided in an embodiment of the present application;

[0037] Figure 6 A schematic diagram of the structure of another dual-cell detection circuit provided in an embodiment of the present application;

[0038] Figure 7 A sinusoidal pulse width modulation diagram provided in an embodiment of the present application;

[0039] Figure 8 A schematic diagram of the structure of another dual-cell detection circuit provided in an embodiment of the present application;

[0040] Fig. 9 A schematic diagram of the structure of a dual-cell detection circuit provided in an embodiment of the present application;

[0041] Fig.10 A schematic diagram of a dual-cell detection method provided in an embodiment of the present application;

[0042] Fig.11 A schematic diagram of another dual-cell detection method provided in an embodiment of the present application;

[0043] Fig.12 A schematic diagram of the structure of a battery cell provided in an embodiment of the present application;

[0044] Fig.13 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0045] The terms "first", "second", "third", etc. in the specification, claims and drawings of this application are used to distinguish different objects rather than to limit a specific order.

[0046] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0047] In order to make the description of the following embodiments clear and concise, a brief introduction to the related technology is first given:

[0048] Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET), hereinafter referred to as MOS tube, is a field effect transistor that can be widely used in analog circuits and digital circuits.

[0049] Dual-cell solution: The dual-cell solution refers to a power configuration solution that uses two cells in parallel. The basic principle of the dual-cell solution is to use two cells with the same or different capacities in parallel to increase the total battery capacity and power output, providing larger battery capacity, longer battery life, and higher power output. However, the dual-cell solution also has some challenges and limitations. For example, the inability to effectively monitor the aging health of the dual batteries may lead to imbalance between the batteries and unpredictable battery life.

[0050] Impedance spectroscopy: Impedance spectroscopy is an experimental technique used to study the electrical properties of electrochemical systems or materials, such as resistance, capacitance and conductivity. It studies the interaction between matter and electric field by measuring and analyzing the changes in resistance and capacitance at different frequencies. The basic principle of impedance spectroscopy is to use the resistance and capacitance response caused by alternating current signals in the electrochemical system or material to be tested, and to measure the relevant electrical parameters and construct an impedance spectrum by changing the frequency of the alternating current signal. Usually, an alternating current signal is used to excite the system to be tested, and then the voltage and current responses on the sample are measured.

[0051] In the dual-cell solution, since cells of different capacities have different characteristics and usage histories, the two cells are likely to age at different rates, which will cause the capacity difference between the two cells to gradually increase, making it difficult to accurately monitor the health of the two cells.

[0052] Furthermore, the health of the battery cell will change with factors such as usage time, number of charges, and charging rate. The two cells in a dual-cell solution may be affected by different usage patterns and environmental conditions, making it more difficult to accurately monitor the health of the two cells.

[0053] like Figure 1 and Figure 2 As shown, Figure 1 A schematic diagram of an impedance spectrum provided in an embodiment of the present application, Figure 2 Another impedance spectrum diagram provided in the embodiment of the present application. Figure 1 and Figure 2 In the figure, the abscissa Z' is the real part of the impedance, and the ordinate -Z" is the imaginary part of the impedance. Figure 1 The solid line in the figure is the impedance measured at room temperature, and the dotted line is the impedance measured after the temperature is lowered. Figure 2 The solid line in the middle is the impedance measured when the number of charge and discharge cycles of the battery cell is 0, and the dotted line is the impedance measured after the number of charge and discharge cycles of the battery cell increases.

[0054] In view of the technical problem that the health status of the two cells cannot be measured in the dual-cell solution, the present application provides a dual-cell detection circuit, method and electronic device. In the dual-cell detection circuit, a controller and a control circuit are used to control the generation of a controllable current between the two cells, so that energy transfer occurs between the two cells, and then the controller is used to collect the voltage signals of the two cells and the current signals between the two cells, respectively, to obtain the impedance spectra of the two cells, and to detect the health status of the two cells.

[0055] The dual-cell detection circuit and method provided in the embodiments of the present application are applicable to electronic devices using dual-cell solutions, such as foldable mobile phones, tablet computers, laptop computers, and other portable electronic devices (such as wireless headphones, handheld game consoles, and portable speakers, etc.). The dual-cell solution provides these electronic devices with longer battery life and higher power output to meet users' requirements for battery life and performance.

[0056] Among them, foldable phones can be divided into outward foldable phones, inward foldable phones and clamshell foldable phones.

[0057] The most common type of foldable phone is the outward foldable phone, whose screen can be folded outward from the center to fold the phone into a smaller form. When unfolded, the screen is fully displayed on the front of the phone and provides a larger working area. When folded, the outward foldable phone is more portable and easy to carry.

[0058] The inward folding phone is the opposite of the outward folding phone. Its screen can be folded from the outside to the inside. When folded, the screen is inside, which can provide better screen protection. When unfolded, the inward folding phone provides a large-screen experience similar to the outward folding phone.

[0059] The top-bottom folding phone folds vertically, just like a traditional flip phone. Its screen folds vertically to form a smaller, more compact shape. When unfolded, the top-bottom folding phone's screen presents a vertical strip, similar to a regular smartphone screen.

[0060] In addition, the dual-cell detection circuit and method provided in the embodiments of the present application are also applicable to other energy storage devices that adopt dual-cell solutions, such as portable power banks, power tools, and electric vehicles for outdoor adventures.

[0061] The following is an introduction to the dual-cell detection circuit provided in the embodiment of the present application in conjunction with the accompanying drawings. Figure 3 As shown, Figure 3 The schematic diagram of the structure of a dual-cell detection circuit provided in an embodiment of the present application is shown in FIG. The dual-cell detection circuit is used to detect the impedance of the first cell 300 and the second cell 400, and the dual-cell detection circuit includes a controller 100, a control circuit 200, a MOS tube and a detection resistor Rs. Figure 3 The positive electrode of the first battery cell 300 is used as the first end, the negative electrode of the first battery cell 300 is used as the second end, the positive electrode of the second battery cell 400 is used as the first end, and the negative electrode of the second battery cell 400 is used as the second end.

[0062] The first end of the first battery cell 300 is connected to the first end of the second battery cell 400 through the MOS tube and the detection resistor Rs, and the second end of the first battery cell 300 and the second end of the second battery cell 400 are grounded.

[0063] The controller 100 is used to output a pulse width modulation (PWM) signal to the control circuit 200. After receiving the PWM signal, the control circuit 200 can control the signal to the MOS tube according to the PWM signal to control the resistance change of the MOS tube, change the voltage division size of the MOS tube, and then control the current flowing through the detection resistor Rs.

[0064] After the controller 100 outputs the PWM signal to the control circuit 200, the current impedance of the first battery cell 300 can be calculated based on the current flowing through the detection resistor Rs and the voltage across the first battery cell 300; similarly, the current impedance of the second battery cell 400 can be calculated based on the current flowing through the detection resistor Rs and the voltage across the second battery cell 400.

[0065] In the embodiment of the present application, the control voltage output by the controller 100 to the control circuit 200 is in the form of a PWM signal. In the PWM signal, a periodic square wave signal is generated. By adjusting the ratio of the high level time of the square wave (usually referred to as "pulse width") to the total period, the magnitude of the control voltage can be changed. The voltage and current on the detection resistor Rs are affected by the control voltage, and the current on the detection resistor Rs changes with the change of the control voltage. When the PWM signal is at a high level, the control voltage is not 0, and there is current on the detection resistor Rs. When the PWM signal is at a low level, the control voltage is 0, and the current on the detection resistor Rs is also 0.

[0066] As a field effect transistor, MOS tube has three working modes, namely cut-off region, saturation region and linear region.

[0067] Cut-off Region: When the gate voltage of the MOS tube (the voltage input to the gate, i.e., the voltage output by the control circuit 200 to the MOS tube) is lower than the critical voltage, the MOS tube is completely cut off and does not conduct electricity. At this time, the MOS tube has a very high resistance. Therefore, the cut-off region can be regarded as a high resistance region of the MOS tube.

[0068] Saturation Region: When the gate voltage of the MOS tube is higher than the critical voltage, the MOS tube is in a saturated state, and the current passing through the MOS tube remains basically unchanged. In the saturation region, the MOS tube has a lower resistance, which can be regarded as the low resistance region of the MOS tube.

[0069] Linear region (Triode Region): When the gate voltage of the MOS tube is between the voltage required by the cut-off region and the saturation region, the MOS tube is in a linear state. In the linear region, the resistance of the MOS tube is between the resistance of the cut-off region and the saturation region, and the variable resistance can be achieved within a certain range by adjusting the control voltage.

[0070] In the embodiment of the present application, the control circuit 200 controls the resistance of the MOS tube by outputting a driving signal to the MOS tube, thereby adjusting the voltage division on the MOS tube. Since the detection resistor Rs is connected in series with the MOS tube, by controlling the voltage division on the MOS tube, the voltage on the detection resistor Rs can be adjusted, thereby controlling the current flowing through the detection resistor Rs.

[0071] The magnitude of the current flowing through the detection resistor Rs is the magnitude of the current between the first battery cell 300 and the second battery cell 400. By controlling the current on the detection resistor Rs, current flow and energy transfer occur between the first battery cell 300 and the second battery cell 400. The controller 100 can collect the voltage across the first battery cell 300 and the voltage across the second battery cell 400, and collect the current between the first battery cell 300 and the second battery cell 400, and then calculate the impedance of the first battery cell 300 and the second battery cell 400, respectively.

[0072] In the embodiment of the present application, the controller 100 can adjust the driving signal output by the control circuit 200 by controlling the PWM signal input by the control circuit 200 according to actual needs. The change of the driving signal will cause the resistance of the MOS tube to change, thereby adjusting the current and energy transfer between the first battery cell 300 and the second battery cell 400 to complete the impedance test.

[0073] In a possible implementation, the control circuit 200 includes an amplifier 201, a first resistor R1, a second resistor R2, a third resistor R3 and a fourth resistor R4; wherein the first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4 have the same resistance value. Figure 4 shown.

[0074] The controller 100 is connected to the positive and negative poles of the first battery cell 300 to collect the voltage across the first battery cell 300; the controller is connected to the positive and negative poles of the second battery cell 400 to collect the voltage across the second battery cell 400; the controller 100 collects the current between one pole connected to the MOS tube of the first battery cell 300 (i.e., the positive pole of the first battery cell 300) and one pole connected to the detection resistor Rs of the second battery cell 400 (i.e., the positive pole of the second battery cell 400), and the current between these two poles to obtain the current flowing between the first battery cell 300 and the second battery cell 400 through the detection resistor Rs; the controller 100 is connected to the negative input terminal of the amplifier 201 through the first resistor R1 to output a PWM signal to the amplifier 20.

[0075] The positive input terminal of the amplifier 201 is connected to the first end of the detection resistor Rs through the fourth resistor R4 and is grounded through the third resistor R3; the negative input terminal of the amplifier 201 is connected to the second end of the detection resistor Rs through the second resistor R2; the output terminal of the amplifier 201 is connected to the gate of the MOS tube.

[0076] The positive electrode of the first battery cell 300 is connected to the drain of the MOS tube, and the negative electrode of the first battery cell 300 is grounded. The positive electrode of the second battery cell 400 is connected to the first end of the detection resistor Rs, and the negative electrode of the second battery cell 400 is grounded. The second end of the detection resistor Rs is connected to the source of the MOS tube.

[0077] The output voltage of the output terminal of the amplifier 201 depends on the voltage difference between its positive input and negative input. The controller 100 adjusts the output voltage of the amplifier 201, that is, the voltage output to the MOS tube, by inputting a control voltage to the negative terminal of the control circuit 200.

[0078] In the above-mentioned dual-cell detection circuit, the controller 100 can collect the voltage across the first cell 300, the voltage across the second cell 400, and the current flowing through the detection resistor Rs between the first cell 300 and the second cell 400, and obtain the impedance of the first cell 300 and the second cell 400 through subsequent signal processing.

[0079] In the above dual-cell detection circuit, the first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4 have the same resistance value. There is a virtual short in the dual-cell detection circuit. That is, Among them, v s is the voltage value at the second end of the detection resistor Rs, v is the control voltage output by the controller, I o is the current value on the detection resistor Rs.

[0080] According to the above equation, we can deduce The current on the detection resistor Rs changes with the change of the control voltage. The change form of the control voltage is a PWM signal, and the change form of the current on the detection resistor Rs is also a PWM signal. When the PWM signal corresponding to the control voltage is a high level, the PWM signal corresponding to the current on the detection resistor Rs is also a high level; when the PWM signal corresponding to the control voltage is a low level, the PWM signal corresponding to the current on the detection resistor Rs is also a low level.

[0081] The control circuit 200 controls the resistance of the MOS tube according to the change of the control voltage, so that the resistance value of the MOS tube changes, and then generates a corresponding current on the detection resistor Rs, so that current flows between the first battery cell 300 and the second battery cell 400, providing conditions for the controller to calculate the impedance spectrum of the two battery cells. In the embodiment of the present application, the control voltage is a PWM signal, and the current flowing through the detection resistor Rs changes with the change of the PWM signal.

[0082] As an example, it is proposed that Figure 4 In the dual-cell detection circuit shown in FIG. 1 , the voltage of the first cell 300 is 4.5V, the voltage of the second cell 400 is 3.5V, and the resistance of the detection resistor Rs is 0.2 ohms. The PWM signal output by the controller 100 is as follows: Figure 5A As shown, the PWM signal is set to 100 Hz with a duty cycle of 50% and a voltage of 10 mV; the current flowing through the detection resistor Rs is as follows: Figure 5B As shown, a current of 0.5 amperes can be output, and the current changes with the change of the PWM signal. When the PWM signal corresponding to the voltage is at a high level, the current is 0.5 amperes, and when the PWM signal corresponding to the voltage is at a low level, the current is 0 amperes.

[0083] In a possible implementation, the controller 100 may modulate a corresponding PWM signal according to a sine function of a preset frequency. After the controller 100 determines the impedance of the first battery cell 300 and the second battery cell 400 under the sine function of the current preset frequency, the frequency of the sine function may be changed to change the frequency of the PWM signal, and then the impedance of the first battery cell 300 and the second battery cell 400 at other frequencies of the sine function may be measured.

[0084] By changing the frequency of the sine function multiple times, the impedance of the first battery cell 300 and the second battery cell 400 at different frequencies can be measured. The controller 100 can obtain the impedance spectrum of the first battery cell 300 according to the impedance of the first battery cell 300 at different frequencies, and can obtain the impedance spectrum of the second battery cell 400 according to the impedance of the second battery cell 400 at different frequencies, and then can detect the health status of the first battery cell 300 and the second battery cell 400 according to the impedance spectrum.

[0085] In the embodiments of the present application, the impedance spectrum can be used to evaluate the health and performance of the battery cell. By measuring the impedance spectrum of two battery cells, information about the electrochemical properties, conductivity, charge transfer rate, interface characteristics and battery capacity of the battery cell can be obtained, so as to analyze and monitor the aging and performance of the battery cell.

[0086] When the battery cell ages or is damaged, the characteristic parameters in the impedance spectrum will change. For example, the internal resistance of the battery cell may increase, the electrolyte conductivity may decrease, and the interface characteristics may deteriorate. By monitoring these changes, battery cell health problems can be detected early and corresponding measures can be taken, such as performing battery cell maintenance, replacing batteries, or optimizing charging management strategies.

[0087] By analyzing the impedance spectrum, the electrochemical properties, conductivity, charge transfer rate, interface characteristics and battery capacity of the battery can be evaluated, thereby realizing the monitoring and analysis of battery aging and performance changes, which helps to optimize the stability, reliability and service life of the dual-cell solution.

[0088] In one possible implementation, Figure 6 As shown. The controller includes a PWM module 101, a first analog-to-digital converter 102 (can be referred to as ADC102) and a second analog-to-digital converter 103 (can be referred to as ADC103). The PWM module 101 is connected to the negative input terminal of the amplifier 201 through a first resistor R1; the first analog-to-digital converter 102 is connected to both ends of the first battery cell 300; and the second analog-to-digital converter 203 is connected to both ends of the second battery cell 400.

[0089] An analog-to-digital converter is a circuit component used to convert analog signals into digital signals. It is one of the common input modules in digital systems. It is used to convert analog signals from the external environment (such as voltage, current, temperature, etc.) into digital form so that the digital system can process, analyze and control them.

[0090] The first analog-to-digital converter 102 is used to collect the voltage across the first battery cell 300 and convert the voltage in the form of an analog signal into a voltage in the form of a digital signal; the second analog-to-digital converter 103 is used to collect the voltage across the second battery cell 400 and convert the voltage in the form of an analog signal into a voltage in the form of a digital signal.

[0091] The PWM module 101 is used to generate the PWM signal according to the sine function modulation of the preset frequency, and output the PWM signal to the amplifier 201. In the embodiment of the present application, the PWM module 101 outputs the control voltage to the comparator 201 in the form of a PWM signal. The control voltage is controlled by adjusting the duty cycle of the pulse. The pulse width refers to the high level time of the pulse signal in one cycle, and the duty cycle indicates the proportional relationship between the high level time and one cycle.

[0092] In the dual-cell detection circuit provided in the embodiment of the present application, compared with using a digital-to-analog converter to output a control voltage in the form of an analog signal, the PWM module outputs the control voltage in the form of a PWM signal, which has the following beneficial effects:

[0093] 1.PWM signals are digital signals that directly correspond to binary values ​​and can be more easily integrated and processed with digital systems. This reduces the complexity of analog signal transmission and processing.

[0094] 2. Digital signals have higher accuracy and stability and are not easily affected by noise and interference. Compared with analog signals, digital signals can more accurately represent and control voltage values ​​and provide higher control accuracy.

[0095] 3. Due to the programmability of digital signals, the frequency and duty cycle of the PWM signal can be easily adjusted to achieve different output voltages. Through software configuration, dynamic adjustment and flexible control of parameters can be achieved.

[0096] 4. Circuits that use PWM to output digital signals are usually simpler and less expensive. Compared to analog signal output using DAC modules, PWM modules usually require fewer hardware components, thereby reducing the size of the circuit and allowing for better integration in electronic devices.

[0097] 5. Since digital signals only switch between high and low levels, PWM signals usually have lower energy loss during transmission and processing than analog signals, thereby saving energy consumption.

[0098] In a possible implementation, the PWM module can use sinusoidal pulse width modulation technology to obtain a PWM signal according to a sinusoidal function modulation of a specified frequency. A PWM signal modulated by a sinusoidal function of a specific frequency is usually called a sinusoidal pulse width modulation (SPWM) signal. Figure 7 As shown, Figure 7 A sinusoidal pulse width modulation diagram is provided in the embodiment of the present application. Figure 7 The horizontal axis is time and the vertical axis is amplitude. The process of PWM module generating PWM signal can be:

[0099] First, a sinusoidal reference signal is generated using a sine function (such as Figure 7 The frequency and amplitude of the sine curve are determined by the desired output modulation frequency and amplitude; this can be done mathematically or by using an approximation algorithm for the sine function. Then, a fixed-frequency PWM signal (such as Figure 7The fixed frequency is usually much higher than the required modulation frequency. Further, the duty cycle of the PWM signal is modulated according to the sinusoidal reference signal and the amplitude modulation algorithm. Specifically, the sinusoidal reference signal is compared with the PWM signal, and the duty cycle is adjusted in each PWM cycle according to the comparison result to match the required sinusoidal waveform. Finally, the modulated PWM signal is output, and the duty cycle of the PWM signal has been modulated according to the sinusoidal function.

[0100] The use of sinusoidal pulse width modulation technology to generate PWM signals can achieve smooth modulation and transformation of voltage, making the output PWM signal close to a sinusoidal waveform. It should be noted that the quality and accuracy of the PWM signal depends on the generation algorithm of the sinusoidal reference signal and the performance of the PWM module. In practical applications, additional filtering and correction may be required to improve the waveform quality and reduce harmonics.

[0101] In the embodiment of the present application, PWM signals of different frequencies can be modulated by changing the frequency of the sine function, and the impedance of the first battery cell 300 and the second battery cell 400 at different frequencies can be detected.

[0102] There may be various interference sources in the above dual-cell detection circuit, such as electromagnetic radiation, switching interference, harmonics, etc. These noise signals may be mixed into the dual-cell detection circuit in the form of high frequency. These high-frequency signals may mislead and interfere with the accuracy of current and voltage measurement.

[0103] In one possible implementation, Figure 8 As shown, the dual-cell detection circuit further includes a first low-pass filter 500 and a second low-pass filter 600 .

[0104] The output end of the first low-pass filter 500 is connected to the first analog-to-digital converter 102, and the input end of the first low-pass filter 500 is connected to both ends of the first battery cell 300; the output end of the second low-pass filter 600 is connected to the second analog-to-digital converter 103, and the input end of the second low-pass filter 600 is connected to both ends of the second battery cell 400;

[0105] The first low-pass filter 500 is used to perform low-pass filtering on the signals collected from both ends of the first battery cell 300 ; the second low-pass filter 600 is used to perform low-pass filtering on the signals collected from both ends of the second battery cell 400 .

[0106] The controller 100 is connected to both ends of the first battery cell 300 through a first low-pass filter 500 to collect the voltage of the first battery cell 300 after low-pass filtering and noise reduction; the controller 100 is connected to both ends of the second battery cell 400 through a second low-pass filter 600 to collect the voltage of the second battery cell 400 after low-pass filtering and noise reduction; the controller 100 can also collect the current after low-pass filtering and noise reduction flowing between the first battery cell 300 and the second battery cell 400 through the detection resistor Rs through the first low-pass filter 500 and the second low-pass filter 600.

[0107] In an embodiment of the present application, a low-pass filter is used to remove high-frequency signals in the input signal (such as the voltage signal at both ends of the first battery cell 300 or the voltage signal at both ends of the second battery cell 400), thereby eliminating the interference of the high-frequency signal and retaining only the required low-frequency signal. This can effectively reduce the impact of high-frequency signals on detection accuracy and improve the anti-interference ability of the dual-cell detection circuit. In addition, the low-pass filter can also smooth the collected signal, so that the collected voltage and current are more stable and stable, thereby improving the stability of the dual-cell detection circuit.

[0108] In one possible implementation, Fig. 9 As shown. The dual-cell detection circuit also includes a third low-pass filter 700, and the controller 100 also includes a third analog-to-digital converter 104 (which can be referred to as ADC104). The third analog-to-digital converter 104 is connected to the output end of the third low-pass filter 700, and the input end of the third low-pass filter 700 is connected to the two ends of the detection resistor Rs. The third analog-to-digital converter 104 is used to collect the current signal on the detection resistor Rs as the current flowing through the detection resistor between the first battery cell 300 and the second battery cell 400, and convert the current in the form of an analog signal into the current in the form of a digital signal. The third low-pass filter 700 is used to perform low-pass filtering on the signal collected from both ends of the detection resistor Rs.

[0109] The current signal on the detection resistor Rs collected by the third analog-to-digital converter 104 is more accurate than the current signal obtained by the first analog-to-digital converter 102 and the second analog-to-digital converter 103, and can reduce the influence of the resistance of the connecting line between the two battery cells on the current to a certain extent. The impedance of the first battery cell 300 and the second battery cell 400 calculated based on the current across the detection resistor Rs is more accurate.

[0110] In a possible implementation, the flow of current between the first battery cell 300 and the second battery cell 400 requires not only the generation of current on the detection resistor Rs, but also the existence of a voltage difference between the first battery cell 300 and the second battery cell 400, that is, the voltage of the first battery cell 300 needs to be greater than the voltage of the second battery cell 400, or the voltage of the first battery cell 300 needs to be less than the voltage of the second battery cell 400. Therefore, before performing the impedance spectrum test, both battery cells can be charged, or only one of the battery cells can be charged to generate a voltage difference between the two battery cells. In addition, after charging is completed, it is necessary to stay still for a certain period of time, and then test after the battery state is stable.

[0111] Through the dual-cell detection circuit provided by the embodiment of the present application, the controller 100 sends a PWM signal to the control circuit 200, and the control circuit 200 controls the resistance value of the MOS tube according to the PWM signal, and indirectly adjusts the current on the detection resistor Rs, so that energy conversion occurs between the first cell 300 and the second cell 400, so that the two cells are respectively in a charging or discharging state, and then the controller 100 can calculate the impedance of the two cells. In addition, by changing the frequency of the PWM signal multiple times, the impedance of the two cells at different frequencies can be measured, and then the impedance spectra of the two cells are obtained respectively, and the health status of the two cells is detected respectively according to the impedance spectra.

[0112] In some existing impedance spectrum tests, which are usually offline tests, additional energy storage devices (such as inductors and capacitors) or power excitation devices are used to provide current excitation sources for the battery cells, so that the battery cells are in a charging or discharging state, and then the impedance spectrum of the battery cells is obtained to complete the battery cell health status detection.

[0113] However, the existing impedance spectrum test requires the use of external equipment, which is not only costly but also has complex test control logic. Since it requires external equipment, the existing impedance spectrum test is not suitable for real-time detection of the health status of the battery cell in portable electronic devices.

[0114] The dual-cell detection circuit provided in the embodiment of the present application controls the resistance value of the MOS tube, thereby controlling the current size on the detection resistor Rs, so that current flows between the first cell 300 and the second cell 400, and uses the power of the cell itself to provide a current excitation source, so that the impedance spectrum test of the two cells can be achieved without the help of external equipment. In addition, the dual-cell detection circuit can be integrated in electronic devices, and can complete online testing during the use of electronic devices, making it easier to perform impedance spectrum testing on dual cells and detect the health status of dual cells.

[0115] In addition, the dual-cell detection circuit provided in the embodiment of the present application can also realize balanced control of the dual-cells. Generally, it is usually necessary to keep the power in the two cells consistent. The difference in the power of the cells leads to different usage frequencies or different usage times of the two cells, which in turn leads to different aging degrees of the two cells.

[0116] The dual-cell detection circuit provided in the embodiment of the present application controls the current on the detection resistor Rs, so that current flows between the first cell 300 and the second cell 400 to transfer energy, and finally makes the voltage of the first cell 300 and the second cell 400 the same, stops the energy transfer, and completes the balanced control of the dual cells.

[0117] The above are some specific implementation methods of the dual-cell detection circuit provided in the embodiments of the present application. Based on this, the present application also provides a corresponding dual-cell detection method, which is applied to the dual-cell detection circuit. The dual-cell detection circuit includes a control circuit, a MOS tube and a detection resistor; the first end of the first battery cell is connected to the first end of the second battery cell through the MOS tube and the detection resistor, and the second end of the first battery cell and the second end of the second battery cell are grounded; the control circuit is used to output a drive signal to the MOS tube according to the pulse width modulation PWM signal input at the input end.

[0118] The following is an introduction to the method provided by the embodiment of the present application with reference to the accompanying drawings. Fig.10 As shown, the dual-cell detection method includes:

[0119] S1001: Control the first battery cell and the second battery cell to generate a voltage difference.

[0120] The existence of a voltage difference between the first battery cell and the second battery cell is a prerequisite for current to flow between the first battery cell and the second battery cell. The voltage of the first battery cell may be greater than the voltage of the second battery cell, or the voltage of the first battery cell may be less than the voltage of the second battery cell.

[0121] In the embodiment of the present application, the first battery cell and the second battery cell can be controlled to be charged separately so that a voltage difference is generated between the first battery cell and the second battery cell; or any one of the first battery cell and the second battery cell can be controlled to be charged so that a voltage difference is generated between the first battery cell and the second battery cell.

[0122] In the embodiment of the present application, any one of the dual cells can be controlled to independently power the electronic device, while the other cell maintains its current state, thereby causing a voltage difference between the first cell and the second cell.

[0123] Normally, the voltage of the first battery cell and the second battery cell should not be lower than 0.4 V. 0.4 V is the voltage at which the first battery cell and the second battery cell can work normally. If the voltage of the first battery cell and the second battery cell is lower than 0.4 V, the electronic device may not be powered, and the impedance spectrum test will also be affected to a certain extent.

[0124] After controlling the voltage difference between the first cell and the second cell, the first cell and the second cell need to be left to stand for a certain period of time. The cell will generate heat during the charging or discharging process, and standing still allows the cell to dissipate heat and return to normal temperature, so that the voltage and temperature inside the cell can be stabilized. The impedance of the cell is affected by temperature changes. After controlling the voltage difference between the first cell and the second cell, leaving the first cell and the second cell to stand can prevent the temperature changes caused by the charging and discharging of the cell from affecting the cell impedance spectrum test.

[0125] S1002: Output PWM signal to the control circuit.

[0126] In the embodiment of the present application, the control voltage is in the form of a PWM signal. By outputting the PWM signal to the control circuit, the control circuit can control the resistance of the MOS tube according to the PWM signal, adjust the voltage division between the MOS tube and the detection resistor, and then generate current between the first battery cell and the second battery cell. The PWM signal can be obtained by modulating the PWM module according to the sine function of the specified frequency.

[0127] S1003: Determine the impedance of the first battery cell according to the current flowing through the detection resistor and the voltage across the first battery cell.

[0128] S1004: Determine the impedance of the second battery cell according to the current flowing through the detection resistor and the voltage across the second battery cell.

[0129] The impedance of the first cell at the current frequency can be determined by the voltage across the first cell and the current flowing through the detection resistor between the first cell and the second cell. Similarly, the impedance of the second cell at the current frequency can be determined by the voltage across the second cell and the current flowing through the detection resistor between the first cell and the second cell.

[0130] In the embodiment of the present application, the voltage of the first battery cell and the second battery cell, and the current between the first battery cell and the second battery cell can be collected by an analog-to-digital converter. The current between the first battery cell and the second battery cell can be the current between one pole of the first battery cell connected to the second battery cell, and one pole of the second battery cell connected to the first battery cell; it can also be the current signal on the detection resistor.

[0131] In the embodiment of the present application, the collected voltage signal and current signal can be signals after low-pass filtering. Low-pass filtering can remove high-frequency signals in the signal, eliminate the interference of high-frequency signals, and only retain the required low-frequency signals. This can effectively reduce the impact of high-frequency signals on detection accuracy and improve the accuracy of dual-cell detection results.

[0132] Impedance is complex data in the frequency domain, including real and imaginary parts. Impedance is complex data in the frequency domain, which describes the impedance characteristics of the battery cell at a certain frequency. By calculating the amplitude and phase difference of voltage and current, the impedance of the battery cell at a certain frequency can be determined. After collecting the voltage and current, the current and the voltage of the battery cell are converted from time domain data to frequency domain data through fast Fourier transform (FFT). Then the impedance of the two batteries is calculated separately based on the frequency domain data.

[0133] In the impedance calculation of the battery cell, the voltage and current are usually time series data. After fast Fourier transform, the corresponding frequency domain data is obtained. Then, the frequency domain data corresponding to the voltage of the battery cell is divided by the frequency domain data corresponding to the current to obtain the frequency domain impedance value of the battery cell. The amplitude of the frequency domain impedance value of the battery cell is calculated to obtain the impedance amplitude of the battery cell at a certain frequency. The phase of the frequency domain impedance value is calculated to obtain the impedance phase of the battery cell at a certain frequency.

[0134] like Fig.11 As shown, in a possible implementation, the dual-cell detection method further includes:

[0135] S1005: Switching sine functions of multiple frequencies.

[0136] By switching the frequency of the sine function, the corresponding PWM signal can be modulated. In other words, different PWM signals can be modulated according to sine functions of different frequencies. The PWM signal is an important condition that affects the voltage across the first battery cell, the voltage across the second battery cell, and the current between the first battery cell and the second battery cell. By switching sine functions of multiple frequencies, the impedance of the first battery cell and the second battery cell at different frequencies can be obtained.

[0137] S1006: Determine the impedance of the first battery cell and the impedance of the second battery cell corresponding to the sinusoidal function of each frequency.

[0138] After the frequency of the sine function is switched, the impedance of the first battery cell and the impedance of the second battery cell at each frequency can be obtained by repeatedly executing steps S1002 to S1004.

[0139] S1007: Obtain an impedance spectrum of the first battery cell according to the multiple impedances of the first battery cell; and obtain an impedance spectrum of the second battery cell according to the multiple impedances of the second battery cell.

[0140] The impedance spectrum describes the impedance characteristics of the battery cell at each frequency. After obtaining the impedance amplitude and phase of the battery cell at each frequency, an impedance spectrum can be drawn to show the impedance characteristics and frequency response of the battery cell. Common impedance spectrum diagrams include frequency-modulus spectrum diagram (also called Bode diagram) and Nyquist diagram.

[0141] Through step S1007 , an impedance spectrum describing the impedance characteristics of the first battery cell at each frequency and an impedance spectrum describing the impedance characteristics of the second battery cell at each frequency can be obtained.

[0142] S1008: Determine a health state of the first battery cell according to the impedance spectrum of the first battery cell, and determine a health state of the second battery cell according to the impedance spectrum of the second battery cell.

[0143] Impedance spectroscopy can provide information about the health status of the battery cell. By analyzing the impedance spectrum, data can be obtained to help evaluate the health status of the battery cell, as follows:

[0144] Analyze the change of impedance modulus: The impedance spectrum is a complex value in the frequency domain. The modulus (Magnitude) in the impedance spectrum refers to the absolute value of the complex value of the impedance, which indicates the magnitude of the impedance. If the change of the impedance modulus exceeds the normal range, it may indicate that there is a problem with the battery cell. For example, a significant increase in the impedance modulus may indicate problems such as limited electrochemical reaction, high resistance, or electrode separation inside the battery cell.

[0145] Analyze the frequency response of the battery cell: The frequency response in the impedance spectrum refers to the response characteristics of the impedance to different frequencies, describing the changes in the impedance at each frequency. Analyzing the frequency response in the impedance spectrum can reveal the dynamic characteristics of the battery cell. For example, the peak and valley positions of the frequency response can provide information about the interface between the electrode and the electrolyte. The width and shape changes of the frequency response can reflect the characteristics of the electrode reaction speed, ion transport, etc., thereby evaluating the health of the battery cell.

[0146] Analyze equivalent circuit parameters: Extract equivalent circuit parameters from the impedance spectrum and establish an equivalent circuit model. Equivalent circuit parameters include resistance, capacitance, and inductance. Changing equivalent circuit parameters can reflect physical and chemical changes inside the battery cell. For example, a decrease in battery cell capacity, an increase in internal resistance, or a change in electrode material may indicate that the battery cell is aging or damaged.

[0147] Through the above dual-cell detection method, by controlling the voltage, a current is generated between the first cell and the second cell where there is a voltage difference, so that energy transfer occurs between the first cell and the second cell, and then the voltage signals of the first cell and the second cell, as well as the current signal between the first cell and the second cell are obtained, and the impedance spectra of the two cells are calculated to achieve the detection of the health status. In addition, the impedance spectrum of the dual cell can be completed online without the help of external equipment, which improves the convenience of detection and reduces the detection cost.

[0148] The dual-cell detection method can also be used to balance the dual-cells. The method also includes: when a voltage difference is detected between the first cell and the second cell, generating a control voltage and controlling the current generated on the detection resistor between the first cell and the second cell according to the control voltage.

[0149] By controlling the current generated on the detection resistor between the two cells, the current flows between the two cells, and the current flows from the cell with high voltage to the cell with low voltage. For example, if the voltage of the first cell is higher than the voltage of the second cell, the current flows from the first cell to the second cell. When the voltages of the two cells are equal, no energy transfer occurs between the two cells.

[0150] The above method can help maintain a voltage balance between the two battery cells, thereby improving the performance and life of the dual battery cells and optimizing the energy utilization and charging and discharging process of the dual battery cells.

[0151] The present application also provides a schematic diagram of the structure of the battery cell, such as Fig.12 As shown, the positive electrode of the open circuit voltage OCV is connected to one end of the capacitor C1 through the resistor R0, the voltage between the other end of the capacitor C1 and the negative electrode of the open circuit voltage OCV is the output voltage Vmdl of the battery cell, and the resistor Rn is connected in parallel across the capacitor C1, and U1 represents the polarization link in the battery cell.

[0152] The above are some specific implementations of dual-cell detection circuits and dual-cell detection methods provided in the embodiments of the present application. Based on this, the present application also provides corresponding electronic devices. In some embodiments, the electronic device may be an electronic device that adopts a dual-cell solution, such as a mobile phone, tablet computer, desktop, laptop, notebook computer, ultra-mobile personal computer (Ultra-mobile Personal Computer, UMPC), handheld computer, netbook, personal digital assistant (Personal Digital Assistant, PDA), wearable electronic device, smart watch and other devices. The present application does not impose any special restrictions on the specific form of the above electronic devices. In this embodiment, the structure of the electronic device can be as follows: Fig.13 As shown, Fig.13 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application.

[0153] like Fig.13 As shown, the electronic device may include a processor 110, an external memory interface 120, an internal memory 121, a universal serial bus (USB) interface 130, a charging management module 140, a power management module 141, a first battery cell 300, a second battery cell 400, an antenna 1, an antenna 2, a mobile communication module 150, a wireless communication module 160, an audio module 170, a speaker 170A, a receiver 170B, a microphone 170C, an earphone interface 170D, a sensor module 180, a button 190, a motor 191, an indicator 192, a camera 193, a display screen 194, and a subscriber identification module (SIM) card interface 195, etc. The sensor module 180 may include a pressure sensor 180A, a gyroscope sensor 180B, an air pressure sensor 180C, a magnetic sensor 180D, an acceleration sensor 180E, a distance sensor 180F, a proximity light sensor 180G, a fingerprint sensor 180H, a temperature sensor 180J, a touch sensor 180K, an ambient light sensor 180L, a bone conduction sensor 180M, etc.

[0154] It is to be understood that the structure illustrated in this embodiment does not constitute a specific limitation on the electronic device. In other embodiments, the electronic device may include more or fewer components than shown in the figure, or combine some components, or split some components, or arrange the components differently. The components shown in the figure may be implemented in hardware, software, or a combination of software and hardware.

[0155] The charging management module 140 is used to receive charging input from a charger. The charger may be a wireless charger or a wired charger. In some wired charging embodiments, the charging management module 140 may receive charging input from a wired charger through the USB interface 130. In some wireless charging embodiments, the charging management module 140 may receive wireless charging input through a wireless charging coil of an electronic device. While the charging management module 140 is charging the first battery cell 300 and the second battery cell 400, it may also power the electronic device through the power management module 141.

[0156] In an embodiment of the present application, the charging management module 140 can charge only the first battery cell 300 or the second battery cell 400 separately according to the control command of the power management module 141, or charge the first battery cell 300 and the second battery cell 400 at the same time to generate a voltage difference between the first battery cell 300 and the second battery cell 400.

[0157] The power management module 141 is used to connect the first battery cell 300 and the second battery cell 400, the charging management module 140 and the processor 110. The power management module 141 receives inputs from the first battery cell 300, the second battery cell 400 and / or the charging management module 140, and supplies power to the processor 110, the internal memory 121, the display screen 194, the camera 193, and the wireless communication module 160. The power management module 141 can also be used to monitor parameters such as battery capacity, battery cycle number, battery health status (leakage, impedance), etc. In some other embodiments, the power management module 141 can also be set in the processor 110. In other embodiments, the power management module 141 and the charging management module 140 can also be set in the same device.

[0158] In the embodiment of the present application, the power management module 141 is used to control the current generated between the first battery cell 300 and the second battery cell 400, and to collect the voltage across the first battery cell 300, the voltage across the second battery cell 400, and the current between the first battery cell 300 and the second battery cell 400; the impedance of the first battery cell 300 is determined according to the voltage and current across the first battery cell 300, and the impedance of the second battery cell is determined according to the voltage and current across the second battery cell 400.

[0159] In the embodiment of the present application, the power management module 141 integrates other components in the dual-cell detection circuit except the first cell 300 and the second cell 400, including a controller, a control circuit, a MOS tube and a detection resistor Rs. In the power management module 141, the controller outputs a control voltage to the control circuit, and the control circuit controls the resistance value of the MOS tube according to the control voltage, and indirectly adjusts the current on the detection resistor Rs, so that energy conversion occurs between the first cell 300 and the second cell 400, so that the two cells are respectively in a charging or discharging state, and then the voltage signal and current signal of the two cells are collected by the controller, and the impedance spectrum of the two cells is calculated to complete the detection of the health status of the two cells.

[0160] In the embodiment of the present application, the power management module 141 is also used to send a control command to the charging management module 140, thereby charging the first battery cell 300 and / or the second battery cell 400, so that a voltage difference is generated between the first battery cell 300 and the second battery cell 400.

[0161] In the embodiment of the present application, the power management module 141 is also used to balance the first battery cell 300 and the second battery cell 400 when a voltage difference is detected between the first battery cell 300 and the second battery cell 142, so that the voltages of the first battery cell 300 and the second battery cell 400 are equal.

[0162] The technical solution of this embodiment, in essence, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor to execute all or part of the steps of the method described in each embodiment. The aforementioned storage medium includes: flash memory, mobile hard disk, read-only memory, random access memory, magnetic disk or optical disk, etc., various media that can store program codes.

[0163] Each embodiment in this specification is described in a progressive manner, and the same and similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. Some or all of the modules can be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative work.

[0164] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A dual-cell detection circuit, characterized in that: Used to detect the impedance of a first battery cell and a second battery cell, the output voltages of the first battery cell and the second battery cell are different, comprising a controller, a control circuit, a MOS tube and a detection resistor; the control circuit comprises an amplifier, a first resistor, a second resistor, a third resistor and a fourth resistor; the resistance values ​​of the first resistor, the second resistor, the third resistor and the fourth resistor are equal; The first end of the first battery cell is connected to the first end of the second battery cell through the MOS tube and the detection resistor, and the second end of the first battery cell and the second end of the second battery cell are grounded; The controller is connected to two ends of the first battery cell and two ends of the second battery cell respectively, and is connected to the negative input terminal of the amplifier through the first resistor; The positive input terminal of the amplifier is connected to the first end of the detection resistor through the fourth resistor and is grounded through the third resistor; the negative input terminal of the amplifier is connected to the second end of the detection resistor; the output terminal of the amplifier is connected to the gate of the MOS tube; The positive electrode of the first battery cell is connected to the drain of the MOS tube, and the negative electrode of the first battery cell is grounded; the positive electrode of the second battery cell is connected to the first end of the detection resistor, and the negative electrode of the second battery cell is grounded; the second end of the detection resistor is connected to the source of the MOS tube; The controller is used to output a pulse width modulation (PWM) signal to the control circuit; The control circuit is used to output a driving signal to the MOS tube according to the PWM signal; The controller is used to collect the voltage across the first battery cell, the voltage across the second battery cell, and the current between the first battery cell and the second battery cell; The impedance of the first battery cell is determined according to the voltage across the first battery cell and the current, and the impedance of the second battery cell is determined according to the voltage across the second battery cell and the current.

2. The circuit according to claim 1, characterized in that The controller includes a first analog-to-digital converter, a second analog-to-digital converter and a pulse width modulation (PWM) module; The first analog-to-digital converter is connected to both ends of the first battery cell, and the second analog-to-digital converter is connected to both ends of the second battery cell; the PWM module is connected to the negative input end of the amplifier through the first resistor; The first analog-to-digital converter is used to collect the voltage across the first battery cell; the second analog-to-digital converter is used to collect the voltage across the second battery cell; the PWM module is used to generate the PWM signal according to sinusoidal function modulation of a preset frequency, and output the PWM signal to the amplifier.

3. The circuit according to claim 2, characterized in that The circuit also includes a first low-pass filter and a second low-pass filter; The output end of the first low-pass filter is connected to the first analog-to-digital converter, and the input end of the first low-pass filter is connected to the two ends of the first battery cell; the output end of the second low-pass filter is connected to the second analog-to-digital converter, and the input end of the second low-pass filter is connected to the two ends of the second battery cell.

4. The circuit according to claim 3, characterized in that The circuit further includes a third low pass filter, and the controller further includes a third analog to digital converter; The output end of the third low-pass filter is connected to the third analog-to-digital converter, and the input end of the third low-pass filter is connected to both ends of the detection resistor; the third analog-to-digital converter is used to collect the current flowing through the detection resistor.

5. A dual-cell detection method, applied to a dual-cell detection circuit, the dual-cell detection circuit comprising a control circuit, a MOS tube and a detection resistor; the first end of the first cell is connected to the first end of the second cell through the MOS tube and the detection resistor, and the second end of the first cell and the second end of the second cell are grounded; the control circuit comprises an amplifier, a first resistor, a second resistor, a third resistor and a fourth resistor; the resistance values ​​of the first resistor, the second resistor, the third resistor and the fourth resistor are equal; the positive input end of the amplifier is connected to the first end of the detection resistor through the fourth resistor, and is grounded through the third resistor; the negative input end of the amplifier is connected to the second end of the detection resistor, and receives a pulse width modulation PWM signal through the first resistor; the output end of the amplifier is connected to the gate of the MOS tube to output a driving signal to the MOS tube; The positive electrode of the first battery cell is connected to the drain of the MOS tube, and the negative electrode of the first battery cell is grounded; the positive electrode of the second battery cell is connected to the first end of the detection resistor, and the negative electrode of the second battery cell is grounded; the second end of the detection resistor is connected to the source of the MOS tube; The method comprises: Controlling the first battery cell and the second battery cell to generate a voltage difference; outputting the PWM signal to the control circuit; The impedance of the first battery cell is determined according to the current flowing through the detection resistor and the voltage across the first battery cell, and the impedance of the second battery cell is determined according to the current flowing through the detection resistor and the voltage across the second battery cell.

6. The method according to claim 5, characterized in that The PWM signal is modulated by a sinusoidal function of a preset frequency.

7. The method according to claim 6, characterized in that The method further comprises: Switching sine functions of multiple frequencies; Determine the impedance of the first battery cell and the impedance of the second battery cell corresponding to the sinusoidal function of each frequency; Obtaining an impedance spectrum of the first battery cell according to the multiple impedances of the first battery cell; obtaining an impedance spectrum of the second battery cell according to the multiple impedances of the second battery cell; The health status of the first battery cell is detected according to the impedance spectrum of the first battery cell; and the health status of the second battery cell is detected according to the impedance spectrum of the second battery cell.

8. The method according to any one of claims 5 to 7, characterized in that: The controlling the first battery cell and the second battery cell to generate a voltage difference comprises: The first battery cell and / or the second battery cell are controlled to be charged so that a voltage difference is generated between the first battery cell and the second battery cell.

9. An electronic device, characterized in that: include: A power management module, a first battery cell and a second battery cell; The power management module includes a controller, an amplifier, a first resistor, a second resistor, a third resistor and a fourth resistor; the resistance values ​​of the first resistor, the second resistor, the third resistor and the fourth resistor are equal; The first end of the first battery cell is connected to the first end of the second battery cell through a MOS tube and a detection resistor, and the second end of the first battery cell and the second end of the second battery cell are grounded; The controller is connected to two ends of the first battery cell and two ends of the second battery cell respectively, and is connected to the negative input terminal of the amplifier through the first resistor; The positive input terminal of the amplifier is connected to the first end of the detection resistor through the fourth resistor and is grounded through the third resistor; the negative input terminal of the amplifier is connected to the second end of the detection resistor; the output terminal of the amplifier is connected to the gate of the MOS tube; The positive electrode of the first battery cell is connected to the drain of the MOS tube, and the negative electrode of the first battery cell is grounded; the positive electrode of the second battery cell is connected to the first end of the detection resistor, and the negative electrode of the second battery cell is grounded; the second end of the detection resistor is connected to the source of the MOS tube; The power management module is used to output a driving signal to the MOS tube, control the current generated between the first battery cell and the second battery cell, and collect the voltage across the first battery cell, the voltage across the second battery cell, and the current between the first battery cell and the second battery cell; The impedance of the first battery cell is determined according to the voltage across the first battery cell and the current, and the impedance of the second battery cell is determined according to the voltage across the second battery cell and the current.

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