Battery current measurement method, battery current measurement circuit and electronic device

Abstract

A battery current measurement method, a battery current measurement circuit and an electronic device. The method comprises: acquiring a terminal voltage difference value of a copper foil (102) at a target measurement temperature, and the present current value of a control chip (101) (S201); on the basis of the terminal voltage difference value, the present current value, the target measurement temperature, and a theoretical copper foil impedance corresponding to the copper foil (102) at the target measurement temperature, determining a compensation impedance corresponding to the control chip (101) (S202); on the basis of the theoretical copper foil impedance corresponding to the copper foil (102) at the target measurement temperature, and the compensation impedance, determining a main loop impedance of a battery current measurement circuit (S203); and on the basis of the main loop impedance and the terminal voltage difference value, obtaining a measured current of the battery current measurement circuit at the target measurement temperature (S204). The present method can achieve the effects of measuring a battery current at a high precision and reducing the production cost of a battery current measurement circuit.

Description

Battery current measurement methods, battery current measurement circuits and electronic equipment

[0001] This application claims priority to Chinese Patent Application No. 202510491462.6, filed on April 15, 2025, entitled "Battery Current Measurement Method, Battery Current Measurement Circuit and Electronic Equipment", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of current measurement technology, and more specifically, to a battery current measurement method, a battery current measurement circuit, and an electronic device. Background Technology

[0003] In recent years, with the rapid growth of the national economy, various electronic devices have been introduced to the market, such as portable computers, smart TVs, and mobile phones. Many of these electronic devices rely on batteries for power, and the battery's operating status significantly affects the safety and reliability of these devices. Therefore, battery current measurement circuits are typically deployed in electronic devices to measure the battery's operating current in real time. Based on this current reading, the operating status of the battery and potential faults can be identified, thereby improving the safety and reliability of the electronic devices.

[0004] In related technologies, a precision resistive element R-sense is often deployed in the main circuit of the battery current measurement circuit. The measured current is obtained by measuring the resistance value and the voltage difference between the precision resistive element R-sense in the main circuit and calculating it based on Ohm's law.

[0005] However, when measuring battery current based on related technologies, there is a drawback: the high cost of precision resistor components leads to an increase in the production cost of battery current measurement circuits. Summary of the Invention

[0006] The purpose of this application is to provide a battery current measurement method, a battery current measurement circuit, and an electronic device, which can achieve high-precision measurement of battery current and reduce the production cost of the battery current measurement circuit.

[0007] The embodiments of this application are implemented as follows:

[0008] A first aspect of this application provides a battery current measurement method. The method is applied to a control chip in a battery current measurement circuit. The battery current measurement circuit also includes a copper foil. The control chip is connected to the copper foil, and a preset distance is provided between the copper foil and the control chip. The method includes:

[0009] Obtain the voltage difference across the copper foil at the target detection temperature and the current current value of the control chip;

[0010] The compensation impedance corresponding to the control chip is determined based on the terminal voltage difference of the copper foil, the current current value of the control chip, the target detection temperature, and the theoretical copper foil impedance corresponding to the copper foil at the target detection temperature. The theoretical copper foil impedance is determined based on multiple actual copper foil impedances obtained at each detection temperature.

[0011] The main circuit impedance of the battery current measurement circuit is determined based on the theoretical copper foil impedance corresponding to the copper foil at the target detection temperature and the compensation impedance corresponding to the control chip.

[0012] Based on the main circuit impedance and the voltage difference at the ends of the copper foil, the measured current of the battery current measurement circuit at the target detection temperature is obtained.

[0013] As one possible implementation, the theoretical copper foil impedance is determined based on multiple actual copper foil impedances obtained at various detection temperatures, including:

[0014] Based on each detection temperature and the corresponding actual copper foil impedance, the temperature impedance curve corresponding to the battery current measurement circuit is obtained by fitting.

[0015] Based on the correspondence between the detection temperature and the main circuit impedance indicated by the temperature impedance curve, the first impedance factor, the second impedance factor, the third impedance factor and the fourth impedance factor of the copper foil are determined.

[0016] Based on the first impedance factor, the second impedance factor, the third impedance factor, the fourth impedance factor, and each detection temperature, the theoretical copper foil impedance corresponding to the copper foil at each detection temperature is determined.

[0017] As one possible implementation, based on the first impedance factor, second impedance factor, third impedance factor, fourth impedance factor, and target detection temperature, the theoretical copper foil impedance corresponding to each detection temperature is determined, including:

[0018] Calculate the first product between the first impedance factor and the cube of the detected temperature;

[0019] Calculate the second product between the second impedance factor and the square of the detected temperature;

[0020] Calculate the third product between the third impedance factor and the detection temperature;

[0021] The summation of the first product, the second product, the third product, and the fourth impedance factor is calculated to obtain the theoretical copper foil impedance corresponding to each detection temperature.

[0022] As one possible implementation, the compensation impedance corresponding to the control chip is determined based on the terminal voltage difference of the copper foil, the current value of the control chip, the target detection temperature, and the theoretical copper foil impedance at the target detection temperature. This includes:

[0023] The actual resistance of the copper foil at the target detection temperature is determined based on the voltage difference across the copper foil and the current current of the control chip.

[0024] The compensation impedance corresponding to the control chip is determined based on the actual resistance of the copper foil at the target detection temperature and the theoretical copper foil impedance at the target detection temperature.

[0025] As one possible implementation, the actual resistance of the copper foil at the target detection temperature is determined based on the voltage difference across the copper foil and the current current value of the control chip, including:

[0026] Calculate the first ratio between the terminal voltage difference of the copper foil and the current current value of the control chip;

[0027] Based on the first ratio, determine the actual resistance of the copper foil at the target detection temperature.

[0028] As one possible implementation, the compensation impedance corresponding to the control chip is determined based on the actual resistance of the copper foil at the target detection temperature and the theoretical copper foil impedance at the target detection temperature, including:

[0029] Calculate the difference between the actual resistance of the copper foil at the target detection temperature and the theoretical copper foil impedance at the target detection temperature;

[0030] Based on the difference, determine the corresponding compensation impedance for the control chip.

[0031] As one possible implementation, the main circuit impedance of the battery current measurement circuit is determined based on the theoretical copper foil impedance at the target detection temperature and the compensation impedance of the control chip, including:

[0032] The sum of the theoretical copper foil impedance at the target detection temperature and the compensation impedance of the control chip is calculated to obtain the main circuit impedance of the battery current measurement circuit.

[0033] As one possible implementation, the measured current of the battery current measurement circuit at the target detection temperature is obtained based on the main circuit impedance and the voltage difference across the copper foil, including:

[0034] Calculate the second ratio between the terminal voltage difference of the copper foil and the impedance of the main circuit to obtain the measured current measured by the battery current measurement circuit at the target detection temperature.

[0035] A second aspect of this application provides a battery current measurement circuit, which includes: a battery module, a fuse unit, a switch unit, copper foil, and a control chip.

[0036] The first end of the battery module is connected to the first end of the control chip and the first end of the fuse unit, the second end of the battery module is connected to the second end of the control chip, and the third end of the battery module is connected to one end of the copper foil and the first sampling end of the control chip.

[0037] The second terminal of the fuse unit is connected to the first terminal of the switch unit, the control terminal of the fuse unit is connected to the third terminal of the control chip, and the third terminal of the fuse unit is connected to the copper foil.

[0038] The second end of the switching unit is connected to the positive power supply port, the control end of the switching unit is connected to the fourth end of the control chip, the second sampling end of the control chip is connected to the other end of the copper foil, and the copper foil is also used to connect to the negative power supply port;

[0039] The control chip is used to perform the steps of the battery current measurement method described in the first aspect above.

[0040] A third aspect of this application provides an electronic device that includes the battery current measurement circuit described in the second aspect above.

[0041] The beneficial effects of the embodiments of this application include:

[0042] This application provides a battery current measurement method. A control chip acquires the detected temperature in real time via a built-in temperature acquisition device. Simultaneously, it obtains the voltage difference between the copper foil terminals at the target detection temperature at the current moment through the ports connected to the control chip and the copper foil terminals. The current current flowing through the control chip is also acquired via a built-in current acquisition component. Based on the voltage difference between the copper foil terminals at the target detection temperature, the theoretical copper foil impedance, the current current value of the control chip, and the temperature indicated by the target detection temperature, the compensation impedance corresponding to the control chip is calculated. Based on the theoretical copper foil impedance at the target detection temperature and the compensation impedance corresponding to the control chip, the main circuit impedance of the battery current measurement circuit at the current moment is calculated. Finally, based on the main circuit impedance of the battery current measurement circuit at the current moment and the voltage difference between the copper foil terminals at the target detection temperature, the measurement current of the battery current measurement circuit at the target detection temperature is calculated. By replacing the expensive precision resistors in existing battery current measurement circuits with inexpensive copper foil, the cost of the battery current measurement circuit can be significantly reduced. The copper foil is positioned at a close, pre-set distance from the control chip, and their electrical connection ensures the measurement accuracy of the control chip. This achieves high-precision battery current measurement while reducing the production cost of the battery current measurement circuit. Attached Figure Description

[0043] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 is a schematic diagram of the structure of the first battery current measurement circuit provided in the embodiment of this application;

[0045] Figure 2 is a flowchart of the first battery current measurement method provided in the embodiment of this application;

[0046] Figure 3 is a flowchart of the second battery current measurement method provided in the embodiment of this application;

[0047] Figure 4 is a temperature impedance curve of a copper foil provided in an embodiment of this application;

[0048] Figure 5 is a schematic diagram of a temperature-impedance table for a copper foil provided in an embodiment of this application;

[0049] Figure 6 is a flowchart of the third battery current measurement method provided in the embodiments of this application;

[0050] Figure 7 is a system flowchart of a battery current measurement method provided in an embodiment of this application;

[0051] Figure 8 is a schematic diagram of the structure of the second battery current measurement circuit provided in the embodiment of this application;

[0052] Figure 9 is a schematic diagram of the structure of an electronic device provided in an embodiment of this application.

[0053] Figure descriptions: 10: Battery current measurement circuit; 101: Control chip; 102: Copper foil; 103: Battery module; 104: Fuse unit; 105: Switch unit; 20: Electronic equipment. Detailed Implementation

[0054] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, 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 some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0055] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0056] Currently, battery current measurement circuits are frequently deployed in electronic devices, with precision resistors placed in the main circuit. The measured current is obtained by measuring the resistance and voltage difference of these precision resistors and calculating the current using Ohm's law. However, this approach suffers from the high cost of precision resistors, resulting in high production costs for battery current measurement circuits.

[0057] To address this, this application provides a battery current measurement method. This method acquires the voltage difference between the copper foil terminals at a target detection temperature and the current value of the control chip. Based on the voltage difference between the copper foil terminals, the current value of the control chip, the target detection temperature, and the theoretical copper foil impedance at the target detection temperature, the compensation impedance of the control chip is calculated. The main circuit impedance of the battery current measurement circuit is then calculated based on the theoretical copper foil impedance at the target detection temperature and the compensation impedance of the control chip. Finally, the measurement current of the battery current measurement circuit at the target detection temperature is calculated based on the main circuit impedance and the voltage difference between the copper foil terminals. This achieves high-precision battery current measurement and reduces the production cost of the battery current measurement circuit.

[0058] It is worth noting that existing technologies calculate the current value of the main battery power supply circuit by measuring the resistance value of a precision resistor element deployed on the main circuit and the voltage difference across its terminals. However, the high cost of precision resistor elements further increases the production cost of the battery current measurement circuit. This application, however, replaces the precision resistor element in the prior art with copper foil. By obtaining the actual impedance of the copper foil and various detection temperatures, the theoretical impedance and compensation impedance of the copper foil are calculated. Based on the theoretical impedance and compensation impedance, the main circuit impedance is calculated. The measured current is obtained based on the actual voltage difference across the copper foil and the main circuit impedance. Thus, by replacing the expensive precision resistor element with inexpensive copper foil, the production cost of the battery current measurement circuit is reduced.

[0059] The battery current measurement method and battery current measurement circuit provided in this application will be explained in detail below with reference to the accompanying drawings.

[0060] Figure 1 is a schematic diagram of the structure of the first type of battery current measurement circuit provided in this application. Referring to Figure 1, the battery current measurement circuit 10 provided in this application embodiment includes: a control chip 101 and a copper foil 102. The control chip 101 and the copper foil 102 are electrically connected. A preset distance is provided between the copper foil 102 and the control chip 101 so that the control chip 101 can quickly obtain the real-time impedance and real-time operating temperature of the copper foil 102. The control chip 101 can be implemented by a Gauge IC, and this application does not specifically limit it.

[0061] Optionally, the control chip 101 has a pre-deployed battery current measurement algorithm, and the control chip 101 can calculate the main circuit current of the battery power supply circuit based on the internal algorithm and the acquired electrical parameter information.

[0062] Alternatively, copper foil 102 is an anionic electrolyte material, a thin, continuous metal foil deposited on the substrate layer of the circuit board. Copper foil 102 is made of copper plus a certain proportion of other metals and has extremely low production cost.

[0063] Optionally, the preset distance can be any value between 0.5 mm and 3 mm. The copper foil 102 is located below the control chip 101, and there is a relatively close preset distance between the copper foil 102 and the control chip 101. This can ensure that the copper foil 102 can effectively collect the temperature of the control chip 101 without affecting the power changes of the control chip 101.

[0064] It is worth noting that the battery current measurement method provided in this application is mainly applied to the battery current detection of computer equipment, but it does not mean that the battery current measurement method provided in this application is only applicable to the battery current detection of computer equipment. This application does not make any specific limitation in this regard.

[0065] Figure 2 is a flowchart of the first battery current measurement method provided in this application. This method is applied to the control chip 101 in the battery current measurement circuit 10 shown in Figure 1. Referring to Figure 2, the battery current measurement method provided in this application includes:

[0066] S201. Obtain the voltage difference between the copper foil terminals at the target detection temperature and the current current value of the control chip.

[0067] Optionally, the target detection temperature refers to the ambient temperature of the control chip at the current moment or the actual operating temperature of the copper foil at the current moment, wherein the ambient temperature of the control chip is approximately equal to the actual operating temperature of the copper foil.

[0068] Optionally, the control chip is connected to both ends of the copper foil. The control chip acquires the voltage values ​​at both ends of the copper foil in real time through the two ends electrically connected to the copper foil, and determines the voltage difference between the copper foil at the target detection temperature at the current moment based on the voltage values ​​at both ends of the copper foil. Here, the voltage difference refers to the potential difference between the voltage values ​​at both ends of the copper foil.

[0069] Optionally, the current value refers to the current value flowing through the control chip at the current moment. The control chip can obtain the current value through built-in current acquisition components such as ammeters and current meters. This application does not make specific limitations on this.

[0070] S202. Based on the terminal voltage difference of the copper foil, the current current value of the control chip, the target detection temperature, and the theoretical copper foil impedance corresponding to the copper foil at the target detection temperature, determine the compensation impedance corresponding to the control chip. The theoretical copper foil impedance is determined based on the multiple actual copper foil impedances obtained at each detection temperature.

[0071] Optionally, the theoretical copper foil impedance at the target detection temperature is calculated based on the actual copper foil impedance at the target detection temperature and the indicated temperature value. The compensation impedance for the control chip is then calculated based on the terminal voltage difference of the copper foil at the target detection temperature, the current current value of the control chip, the target detection temperature, and the theoretical copper foil impedance at the target detection temperature. Here, the compensation impedance refers to the impedance value that the control chip needs to compensate for on the copper foil at the current target detection temperature.

[0072] Optionally, the detected temperature can be the actual operating temperature of the copper foil, or it can be the operating environment temperature of the control chip. The detected temperature is mainly obtained by temperature acquisition devices such as thermometers or temperature sensors built into the control chip. This application does not make specific limitations on this.

[0073] Optionally, the actual copper foil impedance refers to the true impedance value of the copper foil at each detection temperature. The control chip obtains the true impedance value of the copper foil at each detection temperature through the sampling terminal connected to the copper foil, and calculates the theoretical impedance value of the copper foil at each detection temperature based on the mapping relationship between the true impedance value of the copper foil and each detection temperature.

[0074] Optionally, the theoretical copper foil impedance refers to the ideal impedance value of the copper foil at various detection temperatures, that is, the theoretical copper foil impedance refers to the impedance value of the copper foil under ideal conditions, while the actual copper foil impedance refers to the real impedance value of the copper foil affected by the external environment.

[0075] It is worth noting that copper foil impedance refers to the resistance of copper foil to the alternating current flowing through the battery current measuring circuit. The resistance of copper foil to the alternating current flowing through the battery current measuring circuit is affected by temperature.

[0076] Optionally, the control chip can perform impedance compensation on the copper foil based on the calculated compensation impedance to improve the electrical capability of the copper foil.

[0077] S203. Determine the main circuit impedance of the battery current measurement circuit based on the theoretical copper foil impedance corresponding to the copper foil at the target detection temperature and the compensation impedance corresponding to the control chip.

[0078] Optionally, the main circuit impedance of the battery current measurement circuit can be calculated based on the theoretical copper foil impedance at the target detection temperature and the compensation impedance of the control chip at the target detection temperature. The main circuit impedance refers to the total impedance of the battery current measurement circuit, and it significantly affects the safety and stability of the circuit.

[0079] S204. Based on the main circuit impedance and the terminal voltage difference of the copper foil, the measured current of the battery current measurement circuit at the target detection temperature is obtained.

[0080] Optionally, by substituting the main circuit impedance and the terminal voltage difference of the copper foil into Ohm's law I = U / R, the measured current of the battery current measuring circuit at the target detection temperature at the current moment can be calculated. The measured current indicates the current value of the battery detected by the battery current measuring circuit at the current moment.

[0081] In this embodiment, the control chip acquires the detected temperature in real time through its built-in temperature acquisition device. Simultaneously, it obtains the voltage difference between the copper foil terminals at the target detection temperature at the current moment through the ports connected to the control chip and the copper foil at both ends. It also acquires the current current flowing through the control chip at the current moment through its built-in current acquisition device. Based on the voltage difference between the copper foil terminals at the target detection temperature, the theoretical copper foil impedance, the current current value of the control chip, and the temperature indicated by the target detection temperature, the compensation impedance corresponding to the control chip is calculated. Based on the theoretical copper foil impedance at the target detection temperature and the compensation impedance corresponding to the control chip, the main circuit impedance of the battery current measurement circuit at the current moment is calculated. Based on the main circuit impedance of the battery current measurement circuit at the current moment and the voltage difference between the copper foil terminals at the target detection temperature, the measurement current of the battery current measurement circuit at the target detection temperature is calculated. By replacing the expensive precision resistors in existing battery current measurement circuits with inexpensive copper foil, the cost of the battery current measurement circuit can be significantly reduced. The copper foil is positioned directly below the control chip and electrically connected to it, ensuring the measurement accuracy of the control chip. This allows for high-precision measurement of battery current while reducing the production cost of battery current measurement circuits.

[0082] In one possible implementation, referring to Figure 3, the operation of determining the theoretical copper foil impedance mentioned in step S202 based on multiple actual copper foil impedances obtained at various detection temperatures can specifically be as follows:

[0083] S301. Based on each detection temperature and the corresponding actual copper foil impedance, the temperature impedance curve corresponding to the battery current measurement circuit is obtained by fitting.

[0084] Optionally, based on the mapping relationship between each detection temperature and each actual copper foil impedance, a temperature impedance curve corresponding to the battery current measurement circuit is fitted. The temperature impedance curve is used to describe the linear relationship between each detection temperature and the main circuit impedance of the battery current measurement circuit.

[0085] S302. Based on the correspondence between the detection temperature and the main circuit impedance indicated by the temperature impedance curve, determine the first impedance factor, second impedance factor, third impedance factor and fourth impedance factor of the copper foil.

[0086] Optionally, the main circuit impedance refers to the sum of the compensation impedance of the control chip in the battery current measurement circuit at each detection temperature and the theoretical copper foil impedance.

[0087] Optionally, the first impedance factor, the second impedance factor, the third impedance factor, and the fourth impedance factor are all factors that affect the impedance value of the copper foil. The first impedance factor, the second impedance factor, the third impedance factor, and the fourth impedance factor are only used to distinguish the number of impedance factors and do not represent the magnitude of the influence of the impedance factors.

[0088] Optionally, based on the linear relationship between multiple detection temperatures and multiple main circuit impedances indicated by the temperature impedance curve, the values ​​of the first impedance factor, the second impedance factor, the third impedance factor, and the fourth impedance factor affecting the copper foil impedance are calculated.

[0089] It is worth noting that the first impedance factor, the second impedance factor, the third impedance factor, and the fourth impedance factor are calculated constant factors that affect the actual copper foil impedance and have no actual physical meaning.

[0090] S303. Based on the first impedance factor, the second impedance factor, the third impedance factor, the fourth impedance factor, and each detection temperature, determine the theoretical copper foil impedance corresponding to the copper foil at each detection temperature.

[0091] Optionally, based on the first impedance factor, the second impedance factor, the third impedance factor, the fourth impedance factor, and the detection temperature at the current moment, the theoretical copper foil impedance at the current detection temperature can be calculated.

[0092] It is worth noting that the main circuit impedance of the battery current measurement circuit is the theoretical impedance. The main circuit impedance of the battery current measurement circuit is the sum of impedances calculated based on the theoretical copper foil impedance and the compensation impedance of the control chip.

[0093] In one optional embodiment, Figure 4 is a temperature impedance curve of copper foil provided in this application. Referring to Figure 4, based on each detection temperature and the actual copper foil impedance at each detection temperature, a temperature impedance curve between each detection temperature and the main circuit impedance of the battery current measuring circuit is fitted. In Figure 4, the main circuit impedance of the battery current measuring circuit has a linear relationship with each detection temperature. As the detection temperature increases, the main circuit impedance of the battery current measuring circuit also increases positively.

[0094] In one possible implementation, step S303 can specifically be:

[0095] Calculate the first product between the first impedance factor and the cube of the detected temperature;

[0096] Calculate the second product between the second impedance factor and the square of the detected temperature;

[0097] Calculate the third product between the third impedance factor and the detection temperature;

[0098] The summation of the first product, the second product, the third product, and the fourth impedance factor is calculated to obtain the theoretical copper foil impedance corresponding to each detection temperature.

[0099] Alternatively, the theoretical copper foil impedance at each detection temperature can be calculated according to the following formula (1):

[0100] R1=a×T^3+b×T^2+c×T+d(1)

[0101] It is worth noting that R1 represents the theoretical copper foil impedance at the detection temperature T, a represents the first impedance factor of the copper foil, b represents the second impedance factor of the copper foil, c represents the third impedance factor of the copper foil, d represents the fourth impedance factor of the copper foil, and T represents the detection temperature value at the current moment.

[0102] The first impedance factor a, the second impedance factor b, the third impedance factor c, and the fourth impedance factor d can be either positive or negative, and this application does not impose any specific limitations on them. It is worth noting that, to improve the accuracy of the actual operating temperature acquisition of the copper foil, the copper foil is positioned directly below the control chip. Furthermore, to improve the impedance acquisition accuracy of the copper foil, the fourth impedance factor d can be calibrated and adjusted under different temperature conditions.

[0103] Optionally, the calculated first impedance factor a, second impedance factor b, third impedance factor c, and fourth impedance factor d are configured into the control chip. The control chip can calculate the theoretical copper foil impedance corresponding to the copper foil at that temperature based on the real-time detected temperature value and the actual copper foil impedance.

[0104] In one optional embodiment, Figure 5 is a schematic diagram of a temperature-impedance table for copper foil provided in this application. Referring to Figure 5, the actual impedance is used to indicate the actual main circuit impedance of the battery current measurement circuit at the detection temperature, the theoretical impedance is used to indicate the main circuit impedance of the battery current measurement circuit at the detection temperature, and the error rate is used to indicate the error between the theoretical impedance and the actual impedance of the battery current measurement circuit. The theoretical impedance of the battery current measurement circuit is calculated from the theoretical copper foil impedance and the compensation impedance of the control chip, while the actual impedance of the battery current measurement circuit is the impedance obtained by direct measurement.

[0105] In one possible implementation, referring to Figure 6, step S202 can be specifically described as follows:

[0106] S601. Determine the actual resistance of the copper foil at the target detection temperature based on the terminal voltage difference of the copper foil and the current current value of the control chip.

[0107] Optionally, under a relatively stable temperature environment, the voltage values ​​at two points on the copper foil are collected via a cable connecting the control chip and the two ends of the copper foil, and the voltage difference between the ends of the copper foil is calculated. At the same time, the current value of the control chip at the current moment is obtained via the current acquisition device built into the control chip.

[0108] S602. Determine the compensation impedance corresponding to the control chip based on the actual resistance of the copper foil at the target detection temperature and the theoretical copper foil impedance at the target detection temperature.

[0109] Optionally, the compensation impedance that the control chip should provide can be obtained based on the difference between the actual resistance of the copper foil and the theoretical impedance of the copper foil at the target detection temperature at the current moment.

[0110] In one possible implementation, step S601 can specifically be:

[0111] Calculate the first ratio between the terminal voltage difference of the copper foil and the current current value of the control chip;

[0112] Based on the first ratio, determine the actual resistance of the copper foil at the target detection temperature.

[0113] Alternatively, the actual resistance of the copper foil at the target detection temperature at the current moment can be calculated according to the following formula (2):

[0114] Ra=V1÷I1(2)

[0115] It is worth noting that Ra represents the actual resistance of the copper foil at the target detection temperature at the current moment, V1 represents the voltage difference across the copper foil at the target detection temperature at the current moment, and I1 represents the current current of the control chip at the target detection temperature at the current moment.

[0116] In one possible implementation, step S602 can specifically be:

[0117] Calculate the difference between the actual resistance of the copper foil at the target detection temperature and the theoretical copper foil impedance at the target detection temperature;

[0118] Based on the difference, determine the corresponding compensation impedance for the control chip.

[0119] Alternatively, the compensation impedance that the control chip should provide at the target detection temperature at the current moment can be calculated according to the following formula (3):

[0120] R2 = Ra - R1(3)

[0121] It is worth noting that R2 represents the compensation impedance of the control chip at the target detection temperature at the current moment, Ra represents the actual resistance of the copper foil at the target detection temperature at the current moment, and R1 represents the theoretical copper foil impedance at the target detection temperature at the current moment.

[0122] In one possible implementation, step S203 can specifically be:

[0123] The sum of the theoretical copper foil impedance at the target detection temperature and the compensation impedance of the control chip is calculated to obtain the main circuit impedance of the battery current measurement circuit.

[0124] Optionally, the main circuit impedance of the battery current measurement circuit at the target detection temperature at the current moment can be calculated according to the following formula (4):

[0125] R=[a×T^3+b×T^2+c×T+d]+R2(4)

[0126] It is worth noting that R represents the main circuit impedance of the battery current measurement circuit at the target detection temperature at the current moment, a represents the first impedance factor of the copper foil, b represents the second impedance factor of the copper foil, c represents the third impedance factor of the copper foil, d represents the fourth impedance factor of the copper foil, T represents the detection temperature value at the current moment, and R2 represents the compensation impedance of the control chip at the target detection temperature at the current moment.

[0127] In one possible implementation, step S204 can specifically be:

[0128] Calculate the second ratio between the terminal voltage difference of the copper foil and the impedance of the main circuit to obtain the measured current measured by the battery current measurement circuit at the target detection temperature.

[0129] Alternatively, the measured current measured by the battery current measuring circuit at the target detection temperature at the current moment can be calculated according to the following formula (5):

[0130] I = V1 ÷ R (5)

[0131] It is worth noting that I represents the measured current of the battery current measuring circuit at the target detection temperature at the current moment, V1 represents the terminal voltage difference of the copper foil at the target detection temperature at the current moment, and R represents the main circuit impedance of the battery current measuring circuit at the target detection temperature at the current moment.

[0132] Figure 7 is a system flowchart of a battery current measurement method provided in this application. Referring to Figure 7, the actual copper foil impedance of the copper foil is tested at multiple detection temperatures, such as 0℃ to 60℃. Based on the actual copper foil impedance at these temperatures, the theoretical temperature impedance curve of the battery current measurement circuit is fitted. The first impedance factor, second impedance factor, third impedance factor, and fourth impedance factor of the copper foil are calculated and configured into the control chip. The control chip calculates the compensation impedance based on the real-time temperature and the actual copper foil impedance, and performs impedance compensation on the actual copper foil impedance. Based on the current voltage difference of the copper foil and the compensated main circuit impedance, the control chip calculates the measurement current of the battery current measurement circuit.

[0133] In one optional implementation, referring to FIG8, the battery current measurement circuit 10 provided in this application embodiment includes: a battery module 103, a fuse unit 104, a switch unit 105, a copper foil 102, and a control chip 101.

[0134] The first end of the battery module 103 is connected to the first end of the control chip 101 and the first end of the fuse unit 104, the second end of the battery module 103 is connected to the second end of the control chip 101, and the third end of the battery module 103 is connected to one end of the copper foil 102 and the first sampling end of the control chip 101.

[0135] The second end of the fuse unit 104 is connected to the first end of the switch unit 105, the control end of the fuse unit 104 is connected to the third end of the control chip 101, and the third end of the fuse unit 104 is connected to the copper foil 102.

[0136] The second end of the switching unit 105 is connected to the positive power supply port, the control end of the switching unit 105 is connected to the fourth end of the control chip 101, the second sampling end of the control chip 101 is connected to the other end of the copper foil 102, and the copper foil 102 is also used to connect to the negative power supply port.

[0137] The control chip 101 is used to implement any embodiment of the above-described battery current measurement method.

[0138] Figure 9 is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Referring to Figure 9, the electronic device 20 provided in this embodiment of the application includes a battery current measurement circuit 10. The electronic device 20 implements the steps in any of the above method embodiments via the control chip 101 in the battery current measurement circuit 10.

[0139] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0140] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for measuring battery current, characterized in that, The method is applied to a control chip in a battery current measurement circuit. The battery current measurement circuit also includes a copper foil. The control chip is connected to the copper foil, and a preset distance is maintained between the copper foil and the control chip. The method includes: Obtain the voltage difference across the copper foil at the target detection temperature and the current current value of the control chip; The compensation impedance corresponding to the control chip is determined based on the terminal voltage difference of the copper foil, the current current value of the control chip, the target detection temperature, and the theoretical copper foil impedance corresponding to the copper foil at the target detection temperature. The theoretical copper foil impedance is determined based on multiple actual copper foil impedances obtained at each detection temperature. The main circuit impedance of the battery current measurement circuit is determined based on the theoretical copper foil impedance corresponding to the copper foil at the target detection temperature and the compensation impedance corresponding to the control chip. The measured current of the battery current measuring circuit at the target detection temperature is obtained based on the main circuit impedance and the terminal voltage difference of the copper foil.

2. The battery current measurement method according to claim 1, characterized by, The theoretical copper foil impedance is determined based on multiple actual copper foil impedances obtained at various detection temperatures, including: Based on each detection temperature and the corresponding actual copper foil impedance, the temperature impedance curve corresponding to the battery current measurement circuit is fitted to obtain the battery current measurement circuit. Based on the correspondence between the detection temperature and the main circuit impedance indicated by the temperature impedance curve, the first impedance factor, the second impedance factor, the third impedance factor, and the fourth impedance factor of the copper foil are determined. Based on the first impedance factor, the second impedance factor, the third impedance factor, the fourth impedance factor, and each detection temperature, the theoretical copper foil impedance corresponding to the copper foil at each detection temperature is determined.

3. The battery current measurement method according to claim 2, characterized by, The step of determining the theoretical copper foil impedance corresponding to each detection temperature based on the first impedance factor, the second impedance factor, the third impedance factor, the fourth impedance factor, and the target detection temperature includes: Calculate the first product between the first impedance factor and the cube of the detected temperature; Calculate the second product between the second impedance factor and the square of the detected temperature; Calculate the third product between the third impedance factor and the detected temperature; The sum of the first product, the second product, the third product, and the fourth impedance factor is calculated to obtain the theoretical copper foil impedance corresponding to the copper foil at each of the detection temperatures.

4. The battery current measurement method of claim 1, wherein, The step of determining the compensation impedance corresponding to the control chip based on the terminal voltage difference of the copper foil, the current current value of the control chip, the target detection temperature, and the theoretical copper foil impedance corresponding to the copper foil at the target detection temperature includes: The actual resistance of the copper foil at the target detection temperature is determined based on the voltage difference across the copper foil and the current current value of the control chip. The compensation impedance corresponding to the control chip is determined based on the actual resistance of the copper foil at the target detection temperature and the theoretical copper foil impedance at the target detection temperature.

5. The battery current measurement method according to claim 4, wherein Determining the actual resistance of the copper foil at the target detection temperature based on the terminal voltage difference of the copper foil and the current current value of the control chip includes: Calculate a first ratio between the terminal voltage difference of the copper foil and the current current value of the control chip; Based on the first ratio, the actual resistance of the copper foil at the target detection temperature is determined.

6. The battery current measurement method according to claim 4, wherein The step of determining the compensation impedance corresponding to the control chip based on the actual resistance value of the copper foil at the target detection temperature and the theoretical copper foil impedance at the target detection temperature includes: Calculate the difference between the actual resistance of the copper foil at the target detection temperature and the theoretical copper foil impedance at the target detection temperature; Based on the difference, the compensation impedance corresponding to the control chip is determined.

7. The battery current measurement method of claim 1, wherein, The step of determining the main circuit impedance of the battery current measurement circuit based on the theoretical copper foil impedance corresponding to the copper foil at the target detection temperature and the compensation impedance corresponding to the control chip includes: The sum of the theoretical copper foil impedance corresponding to the copper foil at the target detection temperature and the compensation impedance corresponding to the control chip is calculated to obtain the main circuit impedance of the battery current measurement circuit.

8. The battery current measurement method of claim 1, wherein, The step of obtaining the measurement current of the battery current measurement circuit at the target detection temperature based on the main circuit impedance and the terminal voltage difference of the copper foil includes: Calculate the second ratio between the terminal voltage difference of the copper foil and the impedance of the main circuit to obtain the measured current measured by the battery current measuring circuit at the target detection temperature.

9. A battery current measurement circuit, comprising: The battery current measurement circuit includes: a battery module, a fuse unit, a switch unit, copper foil, and a control chip; The first end of the battery module is connected to the first end of the control chip and the first end of the fuse unit, the second end of the battery module is connected to the second end of the control chip, and the third end of the battery module is connected to one end of the copper foil and the first sampling end of the control chip. The second end of the fuse unit is connected to the first end of the switch unit, the control end of the fuse unit is connected to the third end of the control chip, and the third end of the fuse unit is connected to the copper foil. The second end of the switching unit is connected to the positive power supply port, the control end of the switching unit is connected to the fourth end of the control chip, the second sampling end of the control chip is connected to the other end of the copper foil, and the copper foil is also used to connect to the negative power supply port; The control chip is used to perform the steps of the battery current measurement method according to any one of claims 1-8.

10. An electronic device, comprising: The electronic device is equipped with the battery current measurement circuit of claim 9.

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