Battery voltameter, electronic equipment and method for determining electric quantity of battery

Abstract

The invention discloses a battery voltameter, electronic equipment and a method for determining the electric quantity of a battery, and the battery voltameter is used for detecting the electric quantity of a target battery in a battery circuit, and comprises a power supply unit which is used for outputting a power supply voltage; the bias voltage unit is connected with the power supply unit and used for converting the power supply voltage into bias voltage; the differential sampling unit is connected with the bias voltage unit and connected with a to-be-tested unit in the battery circuit, and the differential sampling unit is used for outputting voltage difference data according to the voltage of the to-be-tested unit and the bias voltage; and the control unit is connected with the differential sampling unit and the bias voltage unit, and is used for sampling the bias voltage output by the bias voltage unit and the voltage difference data output by the differential sampling unit, and obtaining the electric quantity of the target battery according to the difference value between the voltage difference data and the bias voltage. The precision of obtaining the electric quantity of the target battery can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of battery detection, and in particular to a battery fuel gauge, an electronic device, and a method for determining the battery power. Background Art

[0002] At present, in various electronic devices equipped with batteries, the control unit generally reads the battery voltage provided by the battery management unit of the battery and calculates the battery power according to the battery voltage. However, there is a problem of large voltage measurement error when directly obtaining the battery voltage through the battery management unit, which leads to low accuracy of the battery power obtained through the battery voltage, and thus fails to provide users with accurate power information of the electronic device, reducing the user experience. Summary of the invention

[0003] In view of this, the present application provides a battery power meter, an electronic device and a method for determining the battery power, which are used to improve the accuracy of obtaining the power of a target battery. The technical solution of the present application is as follows: A battery fuel gauge is used to detect the power level of a target battery in a battery circuit, and the battery fuel gauge includes: a power supply unit, used to output a power supply voltage; a bias voltage unit, connected to the power supply unit, used to convert the power supply voltage into a bias voltage; a differential sampling unit, connected to the bias voltage unit and to a unit to be tested in the battery circuit, the differential sampling unit being used to output pressure difference data according to the voltage of the unit to be tested and the bias voltage; a control unit, connected to the differential sampling unit and the bias voltage unit, used to sample the bias voltage output by the bias voltage unit and the pressure difference data output by the differential sampling unit, and obtain the power level of the target battery according to the difference between the pressure difference data and the bias voltage.

[0004] In one embodiment of the present application, the unit under test is connected to the positive terminal and the negative terminal of the target battery, the positive terminal of the target battery includes the ground terminal of the power circuit of the target battery, and the negative terminal of the target battery includes the battery ground terminal.

[0005] In one embodiment of the present application, the differential sampling unit includes: a differential amplifier circuit, connected to the unit to be tested and the bias voltage unit, for receiving the voltage of the unit to be tested and the bias voltage, and outputting the voltage difference data according to the voltage of the unit to be tested and the bias voltage.

[0006] In an embodiment of the present application, the differential sampling unit further includes: a filtering circuit connected to the differential amplifier circuit and the control unit, and configured to filter the pressure difference data and transmit the filtered data to the control unit.

[0007] In one embodiment of the present application, the differential amplifier circuit includes a first amplifier, a first resistor, a second resistor, a third resistor, a fourth resistor and a first capacitor; the first input terminal of the first amplifier is connected to the positive terminal of the target battery and the first terminal of the unit to be tested through the first resistor, and the second input terminal of the first amplifier is connected to the negative terminal of the target battery and the second terminal of the unit to be tested through the second resistor; the first input terminal of the first amplifier is also connected to the output terminal of the first amplifier through the third resistor, and the second input terminal of the first amplifier also receives the bias voltage through the fourth resistor; the first capacitor is connected in parallel with the unit to be tested.

[0008] In one embodiment of the present application, the filtering circuit includes a fifth resistor and a second capacitor; the first end of the fifth resistor is connected to the output end of the differential amplifier circuit, and the second end of the fifth resistor is connected to the control unit; the first end of the second capacitor is connected to the second end of the fifth resistor, and the second end of the second capacitor is grounded.

[0009] In one embodiment of the present application, the bias voltage unit includes: a voltage divider circuit connected to the power supply unit, used to divide the power supply voltage and output a divided voltage; a voltage following circuit connected to the voltage divider circuit, used to convert the divided voltage into the bias voltage and output it to the differential sampling unit and the control unit.

[0010] In one embodiment of the present application, the voltage divider circuit includes a sixth resistor and a seventh resistor, and the voltage following circuit includes a second amplifier, a third capacitor and a fourth capacitor; the first input terminal of the second amplifier is connected to the output terminal, the second input terminal of the second amplifier is connected to the first end of the sixth resistor, the second end of the sixth resistor is used to receive the supply voltage, and the second input terminal of the second amplifier is also grounded through the seventh resistor and through the third capacitor respectively; the output terminal of the second amplifier is grounded through the fourth capacitor and is connected to the differential sampling unit and the control unit.

[0011] In one embodiment of the present application, the power supply unit includes a power chip, a fifth capacitor and a sixth capacitor; the input end of the power chip is used to receive the power supply voltage and is grounded through the fifth capacitor; the ground end of the power chip is used for grounding; the output end of the power chip is used to output the supply voltage and is grounded through the sixth capacitor.

[0012] In an embodiment of the present application, the output end of the power chip is also connected to the control unit to provide a reference voltage for the control unit.

[0013] In an embodiment of the present application, the difference between the voltage difference data and the bias voltage is equal to n times the voltage of the unit under test, where n is the amplification factor of the differential amplifier circuit.

[0014] In an embodiment of the present application, the current value flowing through the unit to be tested is the same as the current value flowing through the target battery, and the unit to be tested is a sampling resistor.

[0015] A second aspect of the present application provides an electronic device, including a battery circuit and the battery fuel meter.

[0016] A third aspect of the present application provides a method for determining battery power, which is applied to a battery power meter, wherein the battery power meter is used to detect the power of a target battery in a battery circuit, and the battery power meter includes: a power supply unit, a bias voltage unit, and a differential sampling unit; the power supply unit is used to output a power supply voltage; the bias voltage unit is connected to the power supply unit and is used to convert the power supply voltage into a bias voltage; the differential sampling unit is connected to the bias voltage unit and is connected to a unit to be tested in the battery circuit, and the differential sampling unit is used to output pressure difference data according to the voltage of the unit to be tested and the bias voltage; the method includes: sampling the bias voltage output by the bias voltage unit and the pressure difference data output by the differential sampling unit; and obtaining the power of the target battery according to the difference between the pressure difference data and the bias voltage.

[0017] It can be understood that the present application outputs the power supply voltage through the power supply unit, and the bias voltage unit converts the power supply voltage into a bias voltage and transmits it to the differential sampling unit and the control unit. The differential sampling unit is connected to the target battery through the unit to be tested in the battery circuit to obtain the pressure difference data between the voltage of the unit to be tested and the bias voltage. The obtained pressure difference data is transmitted to the control unit. Since the control unit receives the bias voltage at the same time, the control unit can sample the bias voltage and the pressure difference data through the same analog-to-digital conversion module. The bias voltage and the pressure difference data are subtracted during calculation, which can eliminate the error caused by the sampling of the analog-to-digital conversion module, thereby improving the accuracy of obtaining the power of the target battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic block diagram of a battery fuel meter provided in an embodiment of the present application.

[0019] Figure 2 It is a schematic block diagram of a differential sampling unit provided in an embodiment of the present application.

[0020] Figure 3 This is a circuit diagram of a differential sampling unit provided in an embodiment of the present application.

[0021] Figure 4It is a schematic block diagram of a bias voltage unit provided in an embodiment of the present application.

[0022] Figure 5 It is a circuit diagram of a bias voltage unit provided in an embodiment of the present application.

[0023] Figure 6 It is a circuit diagram of a power supply unit provided in an embodiment of the present application.

[0024] Figure 7 It is a flowchart of a method for determining battery power provided in an embodiment of the present application. DETAILED DESCRIPTION

[0025] It should be noted that in the embodiments of the present application, "at least one" refers to one or more, and "more than one" refers to two or more than two. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B can be singular or plural. The terms "first", "second", "third", "fourth", etc. (if any) in the specification, claims and drawings of this application are used to distinguish similar objects, rather than to describe a specific order or sequence.

[0026] It should also be noted that the method disclosed in the embodiments of the present application or the method shown in the flowchart includes one or more steps for implementing the method. Without departing from the scope of the claims, the execution order of multiple steps can be interchangeable with each other, and some of the steps can also be deleted.

[0027] At present, in various electronic devices equipped with batteries, the control unit generally reads the battery voltage provided by the battery management unit of the battery and calculates the battery power according to the battery voltage. However, there is a problem of large voltage measurement error when directly obtaining the battery voltage through the battery management unit, which leads to low accuracy of the battery power obtained through the battery voltage, and thus fails to provide users with accurate power information of the electronic device, reducing the user experience.

[0028] The present application provides a battery power meter, an electronic device and a method for determining the battery power, which are used to improve the accuracy of obtaining the power of a target battery.

[0029] Please refer to Figure 1 , Figure 1 A schematic block diagram of a battery fuel gauge provided in an embodiment of the present application, wherein the battery fuel gauge 100 is used to detect the power level of a target battery 201 in a battery circuit 200. The battery fuel gauge 100 includes a power supply unit 110, a bias voltage unit 120, a differential sampling unit 130 and a control unit 140.

[0030] In an embodiment of the present application, the power supply unit 110 is used to output a power supply voltage. The bias voltage unit 120 is connected to the power supply unit 110 and is used to convert the power supply voltage into a bias voltage. The differential sampling unit 130 is connected to the unit to be tested 202 in the battery circuit 200, the unit to be tested 202 is connected to the target battery 201, and the differential sampling unit 130 is also connected to the bias voltage unit 120. The differential sampling unit 130 is used to output the voltage difference data according to the voltage and bias voltage of the unit to be tested 202. In some embodiments, the above-mentioned unit to be tested 202 can be the target battery 201, that is, the differential sampling unit 130 is directly connected to the target battery 201 in the battery circuit 200.

[0031] The control unit 140 is connected to the differential sampling unit 130 and the bias voltage unit 120. The control unit 140 is used to sample the bias voltage output by the bias voltage unit 120 and the pressure difference data output by the differential sampling unit 130, and obtain the power of the target battery 201 according to the difference between the pressure difference data and the bias voltage.

[0032] In some embodiments, in an electronic device provided with the battery fuel gauge 100 described above, the control unit 140 may be a main controller of the electronic device.

[0033] The supply voltage output by the power supply unit 110 can also be transmitted to the control unit 140, that is, the control unit 140 receives the supply voltage of the power supply unit 110 as a voltage reference source, thereby improving the accuracy of the control unit 140 when digitally sampling the pressure difference data.

[0034] It can be understood that the present application outputs the power supply voltage through the power supply unit 110, and the bias voltage unit 120 converts the power supply voltage into a bias voltage and transmits it to the differential sampling unit 130 and the control unit 140. The differential sampling unit 130 is connected to the target battery 201 through the unit to be tested 202 in the battery circuit 200 to obtain the pressure difference data between the voltage of the unit to be tested 202 and the bias voltage. The obtained pressure difference data is transmitted to the control unit 140. Since the control unit 140 receives the bias voltage at the same time, the control unit 140 can sample the bias voltage and the pressure difference data through the same analog-to-digital conversion module. The bias voltage and the pressure difference data are subtracted during calculation, which can eliminate the error caused by the sampling of the analog-to-digital conversion module, thereby improving the accuracy of obtaining the power of the target battery.

[0035] In some embodiments, the unit under test 202 is connected to the positive terminal and the negative terminal of the target battery 201, the positive terminal of the target battery 201 includes the ground terminal of the power circuit of the target battery 201, and the negative terminal of the target battery 201 includes the battery ground terminal, so as to avoid signal crosstalk between the power circuit of the target battery 201 and the differential sampling unit 130, thereby further improving the calculation accuracy of the battery power.

[0036] The current flowing through the unit under test 202 is the same as the current flowing through the target battery 201 . The current of the target battery 202 can be obtained by calculating the current of the unit under test 202 through the voltage of the unit under test 202 , and then the power of the target battery 202 can be calculated according to the current of the target battery 202 .

[0037] Please refer to Figure 2 , Figure 2 A schematic block diagram of a differential sampling unit 130 provided in an embodiment of the present application, wherein the differential sampling unit 130 includes a differential amplifier circuit 131 and a filter circuit 132 .

[0038] The differential amplifier circuit 131 is connected to the unit under test 202 and the bias voltage unit 120 , and is used for receiving the voltage and the bias voltage of the unit under test 202 , and outputting voltage difference data according to the voltage and the bias voltage of the unit under test 202 .

[0039] The filter circuit 132 is connected to the differential amplifier circuit 131 and the control unit 140 , and is used for filtering the pressure difference data and transmitting the filtered data to the control unit 140 .

[0040] Please refer to Figure 3 , Figure 3 A circuit diagram of a differential sampling unit 130 provided in an embodiment of the present application is provided, wherein the differential sampling unit 130 includes a differential amplifier circuit 131 and a filter circuit 132 .

[0041] In the embodiment of the present application, in the battery circuit 200, the unit under test 202 is a sampling resistor R0, a first end of the sampling resistor R0 is connected to the positive terminal of the target battery 201 and the first input terminal of the differential amplifier circuit 131, and a second end of the sampling resistor R0 is connected to the negative terminal of the target battery 201 and the second input terminal of the differential amplifier circuit 131.

[0042] The positive terminal of the target battery 201 includes the ground terminal PGND of the power circuit of the target battery 201 , and the negative terminal of the target battery 201 includes the battery ground terminal GND_BAT.

[0043] The differential amplifier circuit 131 includes a first amplifier A1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4 and a first capacitor C1. The first input terminal -IN1 of the first amplifier A1 is connected to the positive terminal of the target battery 201 (the ground terminal PGND of the power circuit) and the first terminal of the unit under test 202 (the sampling resistor R0) through the first resistor R1, and the second input terminal +IN1 of the first amplifier A1 is connected to the negative terminal of the target battery 201 (the battery ground terminal GND_BAT) and the second terminal of the unit under test 202 (the sampling resistor R0) through the second resistor R2. The first input terminal -IN1 of the first amplifier A1 is also connected to the output terminal OUT1 through the third resistor R3, and the second input terminal +IN1 of the first amplifier A1 also receives a bias voltage through the fourth resistor R4. The first capacitor C1 is connected in parallel with the unit under test 202 (sampling resistor R0 ).

[0044] It can be understood that in the embodiment of the present application, the first operational amplifier A1 amplifies the voltage difference between the two ends of the sampling resistor R0 by a preset multiple and then adds it to the bias voltage The differential processing is performed to output the voltage difference data. Therefore, the difference between the voltage difference data and the bias voltage is equal to n times the voltage of the unit under test 202, where n is the gain of the differential amplifier circuit. For example, when the gain of the first operational amplifier A1 is 10 times, then , where is the pressure difference data, is the voltage difference across the sampling resistor R0.

[0045] The filter circuit 132 includes a fifth resistor R5 and a second capacitor C2. A first end of the fifth resistor R5 is connected to the output end OUT1 of the differential amplifier circuit 131, and a second end of the fifth resistor R5 is connected to the control unit 140. A first end of the second capacitor C2 is connected to the second end of the fifth resistor R5, and a second end of the second capacitor C2 is grounded.

[0046] Please refer to Figure 4 , Figure 4 A schematic block diagram of a bias voltage unit 120 provided in an embodiment of the present application, wherein the bias voltage unit 120 includes a voltage divider circuit 121 and a voltage follower circuit 122 .

[0047] The voltage divider circuit 121 is connected to the power supply unit 110, and is used to receive the power supply voltage output by the power supply unit 110, divide the power supply voltage and output the divided voltage. The voltage follower circuit 122 is connected to the voltage divider circuit 121, and is used to convert the divided voltage into a bias voltage and output it to the differential sampling unit 130 and the control unit 140.

[0048] Please refer to Figure 5 , Figure 5A circuit diagram of a bias voltage unit 120 provided in an embodiment of the present application. The bias voltage unit 120 includes a voltage divider circuit 121 and a voltage follower circuit 122. The voltage divider circuit 121 includes a sixth resistor R6 and a seventh resistor R7. The voltage follower circuit 122 includes a second amplifier A2, a third capacitor C3 and a fourth capacitor C4.

[0049] In the embodiment of the present application, the first input terminal -IN2 of the second amplifier A2 is connected to the output terminal OUT2, the second input terminal +IN2 of the second amplifier A2 is connected to the first end of the sixth resistor R6, the second end of the sixth resistor R6 is used to receive the power supply voltage V, and the second input terminal +IN2 of the second amplifier A2 is also grounded through the seventh resistor R7 and the third capacitor C3. The output terminal OUT2 of the second amplifier A2 is grounded through the fourth capacitor C4 and is connected to the differential sampling unit 130 and the control unit 140.

[0050] It can be understood that in the circuit of the bias voltage unit 120, the supply voltage V passes through the sixth resistor R6 and the seventh resistor R7 and then is input to the second amplifier A2, forming a voltage following circuit, which can convert the supply voltage V into a bias voltage after passing through the second amplifier A2. , while increasing the bias voltage The anti-interference ability makes the bias voltage More stable, thereby improving the sampling accuracy of the differential sampling unit 130.

[0051] Please refer to Figure 6 , Figure 6 A circuit diagram of a power supply unit 110 provided in an embodiment of the present application, wherein the power supply unit 110 includes a power chip U1, a fifth capacitor C5 and a sixth capacitor C6.

[0052] In the embodiment of the present application, the input terminal IN of the power chip U1 is used to receive the power supply voltage VCC and is grounded through the fifth capacitor C5. The ground terminal GND of the power chip U1 is used for grounding. The output terminal OUT of the power chip U1 is used to output the power supply voltage V and is grounded through the sixth capacitor C6.

[0053] In the embodiment of the present application, the control unit 140 is further configured to: And differential pressure data A high-precision battery current of the target battery 201 is obtained, and the power level of the target battery 201 is obtained according to the battery current and the real-time voltage of the target battery 201 .

[0054] For example, the sampling resistance of the differential sampling unit 130 is the resistance of the sampling resistor R0 in the above embodiment, and the amplification factor of the differential sampling unit 130 is the amplification factor of the first amplifier A1 (for example, 10). Then, the formula: , , the above high-precision battery current can be obtained .

[0055] In some embodiments, the output terminal OUT of the power chip U1 is also connected to the control unit 140 to provide a reference voltage for the control unit 140. Since the reference voltage output by the power chip U1 is stable and accurate, the accuracy of the analog-to-digital conversion module of the control unit 140 during sampling can be improved.

[0056] In the embodiment of the present application, after obtaining the battery current and real-time voltage, the control unit 140 can obtain the real-time power of the target battery 201 according to the battery current and real-time voltage, and can obtain the current charging or discharging power percentage of the target battery 201 by integrating the real-time power and dividing it by the rated power value of the target battery 201. When discharging, the control unit 140 can obtain the current power of the target battery 201 by subtracting the above power percentage from the remaining power percentage of the target battery 201. When charging, the control unit 140 can obtain the current power of the target battery 201 by adding the above power percentage to the remaining power percentage of the target battery 201.

[0057] In some embodiments, the control unit 140 may be connected to a battery management unit of the target battery 201 to obtain the real-time voltage of the target battery 201 , or a voltage sampling unit may be provided in the battery fuel meter 100 , and the voltage sampling unit is respectively connected to the positive terminal and the negative terminal of the target battery 201 , for collecting the real-time voltage of the target battery 201 and transmitting it to the control unit 140 .

[0058] The control unit 140 can also With bias voltage The size relationship between them determines whether the target battery 201 is currently in a discharging state or a charging state.

[0059] The present application also provides an electronic device, including a target battery 201 and a battery meter of any of the above embodiments. It can be understood that the beneficial effects of the electronic device can refer to the beneficial effects of the battery meter in the above embodiments, which will not be repeated here. The electronic device can be an intelligent robot device such as a lawn mower robot, and the control unit 140 can be a main controller of the lawn mower robot.

[0060] Please refer to Figure 7 , Figure 7A flowchart of a method for determining battery power provided in an embodiment of the present application. The method for determining battery power is applied to a battery fuel gauge, which is used to detect the power of a target battery in a battery circuit, and the battery fuel gauge includes a power supply unit, a bias voltage unit, and a differential sampling unit according to any of the above embodiments.

[0061] The power supply unit is used to output the power supply voltage. The bias voltage unit is connected to the power supply unit and is used to convert the power supply voltage into the bias voltage. The differential sampling unit is connected to the bias voltage unit and is connected to the unit to be tested in the battery circuit. The differential sampling unit is used to output the pressure difference data according to the voltage and the bias voltage of the unit to be tested.

[0062] The method for determining the battery charge specifically includes the following steps: Step S71: sampling the bias voltage output by the bias voltage unit and the voltage difference data output by the differential sampling unit.

[0063] Step S72: obtaining the power of the target battery according to the difference between the voltage difference data and the bias voltage.

[0064] In the embodiments of the present application, the beneficial effects of the method for determining the battery power level can refer to the beneficial effects of the battery power meter in any of the aforementioned embodiments, which will not be described in detail here.

[0065] An embodiment of the present application further provides a computer storage medium, which stores a computer program. When the computer program is executed by a processor, the processor executes the above-mentioned method for determining the battery power.

[0066] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer storage medium or transmitted through the computer storage medium. The computer instructions may be transmitted from a website site, computer, server or data center to another website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a digital versatile disc (DVD)), or a semiconductor medium (eg, a solid state disk (SSD)).

[0067] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. The aforementioned storage medium includes: ROM, RAM, magnetic disk or optical disk and other media that can store program codes. In the absence of conflict, the technical features in this embodiment and the implementation scheme can be combined arbitrarily.

[0068] The embodiments described above are merely preferred embodiments of the present application and are not intended to limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements made to the technical solutions of the present application by ordinary technicians in this field should fall within the protection scope determined by the claims of the present application.

Claims

1. A battery fuel gauge, characterized in that: The battery fuel gauge is used to detect the power level of a target battery in a battery circuit, and the battery fuel gauge includes: A power supply unit, used for outputting a power supply voltage; a bias voltage unit, connected to the power supply unit, and configured to convert the power supply voltage into a bias voltage; A differential sampling unit connected to the bias voltage unit and to the unit to be tested in the battery circuit, the differential sampling unit being used to output voltage difference data according to the voltage of the unit to be tested and the bias voltage; A control unit is connected to the differential sampling unit and the bias voltage unit, and is used to sample the bias voltage output by the bias voltage unit and the pressure difference data output by the differential sampling unit, and obtain the power of the target battery according to the difference between the pressure difference data and the bias voltage.

2. The battery fuel gauge according to claim 1, wherein: The unit under test is connected to the positive terminal and the negative terminal of the target battery, the positive terminal of the target battery includes the ground terminal of the power circuit of the target battery, and the negative terminal of the target battery includes the battery ground terminal.

3. The battery fuel gauge according to claim 1, wherein: The differential sampling unit comprises: The differential amplifier circuit is connected to the unit to be tested and the bias voltage unit, and is used to receive the voltage of the unit to be tested and the bias voltage, and output the voltage difference data according to the voltage of the unit to be tested and the bias voltage.

4. The battery fuel gauge according to claim 3, characterized in that: The differential sampling unit also includes: The filter circuit is connected to the differential amplifier circuit and the control unit, and is used for filtering the pressure difference data and transmitting the filtered data to the control unit.

5. The battery fuel gauge according to claim 3, wherein: The differential amplifier circuit includes a first amplifier, a first resistor, a second resistor, a third resistor, a fourth resistor and a first capacitor; The first input terminal of the first amplifier is connected to the positive terminal of the target battery and the first terminal of the unit under test through the first resistor, and the second input terminal of the first amplifier is connected to the negative terminal of the target battery and the second terminal of the unit under test through the second resistor; The first input end of the first amplifier is also connected to the output end of the first amplifier through a third resistor, and the second input end of the first amplifier receives the bias voltage through a fourth resistor; the first capacitor is connected in parallel with the unit under test.

6. The battery fuel gauge according to claim 4, characterized in that: The filter circuit includes a fifth resistor and a second capacitor; The first end of the fifth resistor is connected to the output end of the differential amplifier circuit, and the second end of the fifth resistor is connected to the control unit; the first end of the second capacitor is connected to the second end of the fifth resistor, and the second end of the second capacitor is grounded.

7. The battery fuel gauge according to claim 1, wherein: The bias voltage unit comprises: A voltage dividing circuit, connected to the power supply unit, for dividing the supply voltage and then outputting a divided voltage; The voltage following circuit is connected to the voltage dividing circuit and is used for converting the divided voltage into the bias voltage and outputting the bias voltage to the differential sampling unit and the control unit.

8. The battery fuel gauge according to claim 7, wherein: The voltage divider circuit includes a sixth resistor and a seventh resistor, and the voltage follower circuit includes a second amplifier, a third capacitor and a fourth capacitor; The first input terminal of the second amplifier is connected to the output terminal, the second input terminal of the second amplifier is connected to the first terminal of the sixth resistor, the second terminal of the sixth resistor is used to receive the supply voltage, and the second input terminal of the second amplifier is also grounded through the seventh resistor and the third capacitor respectively; the output terminal of the second amplifier is grounded through the fourth capacitor and is connected to the differential sampling unit and the control unit.

9. The battery fuel gauge according to claim 1, wherein: The power supply unit includes a power chip, a fifth capacitor and a sixth capacitor; The input end of the power chip is used to receive the power supply voltage and is grounded through the fifth capacitor; the ground end of the power chip is used to be grounded; the output end of the power chip is used to output the supply voltage and is grounded through the sixth capacitor.

10. The battery fuel gauge according to claim 9, wherein: The output end of the power chip is also connected to the control unit to provide a reference voltage for the control unit.

11. The battery fuel gauge according to claim 3, wherein: The difference between the voltage difference data and the bias voltage is equal to n times the voltage of the unit under test, where n is the amplification factor of the differential amplifier circuit.

12. The battery fuel gauge according to claim 1, wherein: The current value flowing through the unit to be tested is the same as the current value flowing through the target battery, and the unit to be tested is a sampling resistor.

13. An electronic device, characterized in that: The invention comprises a battery circuit and a battery fuel gauge as claimed in any one of claims 1 to 12.

14. A method for determining battery power, characterized in that: Applied to a battery fuel meter, the battery fuel meter is used to detect the power of a target battery in a battery circuit, the battery fuel meter comprises: a power supply unit, a bias voltage unit and a differential sampling unit; The power supply unit is used to output a power supply voltage; the bias voltage unit is connected to the power supply unit and is used to convert the power supply voltage into a bias voltage; the differential sampling unit is connected to the bias voltage unit and is connected to the unit to be tested in the battery circuit, and the differential sampling unit is used to output pressure difference data according to the voltage of the unit to be tested and the bias voltage; The method comprises: sampling the bias voltage output by the bias voltage unit and the voltage difference data output by the differential sampling unit; The power level of the target battery is obtained according to the difference between the voltage difference data and the bias voltage.

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