Battery cell-based battery measurement circuit, battery chip and battery measurement method

Abstract

The invention discloses a battery measuring circuit based on a battery unit, a battery chip and a battery measuring method, and relates to the technical field of battery voltage measurement. The actual capacity of the battery is measured by measuring the internal resistance of the battery. Specifically, voltages of a battery cell are correspondingly measured at different moments, and the voltages measured at the two different moments are stored in different capacitors, namely a first capacitor and a second capacitor. The voltage values of the two capacitors are transferred to the corresponding capacitors to measure the voltage values, the first capacitor and the second capacitor are connected with the in-phase end and the anti-phase end of the differential amplifier respectively, amplification of the voltage difference of the battery cells is achieved, and the voltage measurement precision of the battery cells is improved. The internal resistance of the battery core can be determined through the difference between the current values of the current measuring device at two different moments, so that the measurement accuracy of the battery core is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of battery voltage measurement, and in particular to a battery measurement circuit, a battery chip and a battery measurement method based on a battery unit. Background Art

[0002] A battery system is often composed of multiple battery cells. After the batteries are connected in series, the battery capacities vary, which may lead to inaccurate battery capacity measurement in the battery capacity measurement scheme.

[0003] In the traditional battery capacity measurement method, the battery capacity cannot be accurately determined from the battery voltage. If individual cells age, the corresponding battery internal resistance increases, causing the cell voltage to falsely increase during charging, which will be misjudged as an increase in capacity and then discharged. However, in the actual measurement process, the capacity is small, resulting in a vicious cycle of smaller capacity and easier discharge.

[0004] Therefore, how to improve the measurement accuracy of battery capacity is an urgent problem that those skilled in the art need to solve. Summary of the invention

[0005] The object of the present invention is to provide a battery measurement circuit, a battery chip and a battery measurement method based on a battery unit to solve the problem of low measurement accuracy of battery capacity.

[0006] In order to solve the above technical problems, the present invention provides a battery measurement circuit based on a battery unit, wherein the battery measurement circuit includes a switch matrix, a first capacitor, a second capacitor and a differential amplifier;

[0007] The switch matrix is ​​connected to the battery cell of the battery unit; the first capacitor and the second capacitor are correspondingly connected to the same target battery cell of the battery unit through the switch matrix, so that the same target battery cell is connected to the first capacitor at the first moment and connected to the second capacitor at the second moment; the battery unit is connected to the load, and the current measuring device is arranged in the power supply circuit of the battery unit and the load; wherein the battery unit includes at least one battery cell;

[0008] The first capacitor and the second capacitor are connected to the processor via the non-inverting terminal and the inverting terminal of the differential amplifier respectively; the processor is used to determine the internal resistance value of the target battery cell based on the difference between the amplified data of the difference between the voltage values ​​of the target battery cell corresponding to the first moment and the second moment output by the differential amplifier and the difference between the current values ​​corresponding to the current measuring device.

[0009] In one aspect, the switch matrix comprises a first switch unit;

[0010] The positive electrode of the battery cell passes through the two switches of the first switch unit, and is respectively connected to the first ends of the first capacitor and the second capacitor; the negative electrode of the battery cell passes through the other two switches of the first switch unit, and is respectively connected to the second ends of the first capacitor and the second capacitor.

[0011] On the other hand, the acquisition of the amplified data is determined by multiplying the amplification factor of the differential amplifier by the difference between the voltage values ​​of the same target battery cell; the amplification factor of the differential amplifier is determined by the number of the differential amplifiers connected in series.

[0012] On the other hand, the gain of the differential amplifier is also determined by the resistance relationship between the first resistor and the second resistor of the differential amplifier or by the capacitance relationship between the third capacitor and the fourth capacitor of the differential amplifier.

[0013] On the other hand, it also includes a first AD converter;

[0014] The first AD converter is connected to the output end of the differential amplifier and is also connected to the processor.

[0015] On the other hand, a second AD converter is also included;

[0016] The current measuring device is connected to the second AD converter and is used to measure the current of the battery cell of the power supply circuit and convert it into voltage to output to the second AD converter; the second AD converter is connected to the processor.

[0017] In order to solve the above technical problem, the present invention further provides a battery chip, comprising the above-mentioned battery measurement circuit based on the battery unit.

[0018] In order to solve the above technical problems, the present invention further provides a battery measurement method based on a battery cell, which is applied to a battery measurement circuit based on a battery cell. The method comprises:

[0019] Determine the target battery cell;

[0020] receiving amplified data of a voltage value determined by a voltage value stored in a first capacitor and a second capacitor at a first moment and a second moment of a target battery cell outputted from an output terminal of a differential amplifier; wherein the voltage values ​​corresponding to the first capacitor and the second capacitor are obtained by the target battery cell turning on switches of a correspondingly connected switch matrix and storing them at the first moment and the second moment;

[0021] The first moment and the second moment sent by the receiving current measuring device correspond to the current value of the target battery cell respectively;

[0022] The difference between the current values ​​is determined according to the current values ​​corresponding to the first moment and the second moment; and the internal resistance value of the target battery cell is determined according to the amplified data of the difference between the voltage values ​​and the difference between the current values.

[0023] The present invention provides a battery measurement circuit based on a battery cell, wherein the battery cell of the battery cell is connected to a switch matrix; a first capacitor and a second capacitor are connected to the same target battery cell of the battery cell via the switch matrix, so that the same target battery cell is connected to the first capacitor at the first moment and to the second capacitor at the second moment; the battery cell is connected to a load, and a current measuring device is arranged in a power supply circuit of the battery cell and the load; wherein the battery cell includes at least one battery cell; the first capacitor and the second capacitor are connected to a processor via the in-phase end and the inverting end of a differential amplifier; the processor is used to determine the internal resistance value of the target battery cell according to the difference between the amplified data of the difference between the voltage values ​​of the target battery cell at the first moment and the second moment output by the differential amplifier and the current value corresponding to the current measuring device. The present invention measures the actual capacity of the battery by measuring the internal resistance of the battery. Specifically, by measuring the voltage of the battery cell corresponding to different moments, the voltages measured at two different moments are stored in different capacitors, namely the first capacitor and the second capacitor. The voltage values ​​of the two capacitors are transferred to the corresponding capacitor components to measure the voltage values. The first capacitor and the second capacitor are respectively connected to the non-inverting terminal and the inverting terminal of the differential amplifier to amplify the voltage difference of the battery cells and improve the voltage measurement accuracy of each battery cell. Furthermore, the internal resistance of the battery cell can be determined by the difference in current values ​​of the current measuring device at two different times to improve the measurement accuracy of the battery cell. Compared with the traditional battery capacity measurement method, there is no risk of misjudgment due to measuring the battery capacity, and there will be no vicious cycle of smaller capacity and easier discharge.

[0024] In addition, the present invention also provides a battery chip and a battery measurement method based on a battery cell, which have the same beneficial effects as the above-mentioned battery measurement circuit based on a battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 It is the structural diagram of the traditional battery internal resistance measurement circuit;

[0027] Figure 2 A circuit diagram of a battery measurement circuit based on a battery cell provided by an embodiment of the present invention;

[0028] Figure 3 This is the schematic diagram of the battery internal resistance measurement circuit;

[0029] Figure 4 A structural diagram of another battery measurement circuit based on a battery cell provided by an embodiment of the present invention;

[0030] Figure 5 A structural diagram of a differential amplifier provided in an embodiment of the present invention;

[0031] Figure 6 A structural diagram of another differential amplifier provided in real time by the present invention;

[0032] Figure 7 A schematic diagram of step 1 of measuring the internal resistance of a battery cell provided by an embodiment of the present invention;

[0033] Figure 8 A schematic diagram of step 2 of measuring the internal resistance of a battery cell provided by an embodiment of the present invention;

[0034] Fig. 9 A schematic diagram of step 3 of measuring the internal resistance of a battery cell provided by an embodiment of the present invention;

[0035] Fig.10 A schematic diagram of step 4 of measuring the internal resistance of a battery cell provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] The core of the present invention is to provide a battery measurement circuit, a battery chip and a battery measurement method based on a battery unit to solve the problem of low measurement accuracy of battery capacity.

[0038] In order to enable those skilled in the art to better understand the solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0039] The remaining capacity of the battery cell of the battery power source is evaluated by voltage in the traditional measurement method, which leads to inaccurate measurement. Since the internal resistance of a fully charged battery is the lowest, the internal resistance increases after power consumption. If the battery internal resistance is measured, additional power supply components need to be added. Figure 1 The structure diagram of the traditional battery internal resistance measurement circuit is as follows: Figure 1As shown, an external power source I1 is required to generate a charging and discharging square wave (square wave corresponding to +1A and -1A) to calculate the internal resistance of the battery BAT, and the capacitor C plays a role in DC isolation. In addition, additional components will be generated to consume power, thereby consuming the energy stored in the battery. The battery measurement circuit based on the battery unit provided by the present invention solves the above technical problems.

[0040] Figure 2 A circuit diagram of a battery measurement circuit based on a battery cell provided by an embodiment of the present invention, such as Figure 2 As shown, the battery measurement circuit includes a switch matrix 2, a first capacitor C1, a second capacitor C2 and a differential amplifier 3;

[0041] The switch matrix 2 is connected to the battery cell of the battery unit 1; the first capacitor C1 and the second capacitor C2 are correspondingly connected to the same target battery cell of the battery unit 1 through the switch matrix 2, so that the same target battery cell is connected to the first capacitor C1 at the first moment and connected to the second capacitor C2 at the second moment; the battery unit 1 is connected to the load LOAD1, and the current measuring device 5 is arranged in the power supply circuit of the battery unit 1 and the load LOAD1; wherein the battery unit 1 includes at least one battery cell;

[0042] The first capacitor C1 and the second capacitor C2 are connected to the processor 4 via the non-inverting terminal and the inverting terminal of the differential amplifier 3 respectively; the processor 4 is used to determine the internal resistance value of the target battery cell based on the amplified data of the difference between the voltage values ​​of the target battery cell corresponding to the first moment and the second moment output by the differential amplifier 3 and the difference between the current values ​​corresponding to the current measuring device 5.

[0043] Specifically, the battery unit includes at least one battery cell. The first capacitor and the second capacitor provided in this embodiment are based on the voltage difference of the battery cell collected at different times, and the internal resistance value of the battery cell is obtained by dividing the voltage difference and the current difference of the battery cell based on the current of the battery cell collected at different times.

[0044] Figure 3 The schematic diagram of the battery internal resistance measurement circuit is as follows: Figure 3 As shown in the figure, the dotted line is the equivalent schematic diagram of the battery cell, R represents the internal resistance of the battery, and the corresponding battery voltage difference is determined by dividing the voltage difference by the current difference. Figure 3 The internal resistance of the battery in. That is: ; ; ; .

[0045] It is understandable that the number of battery cells in this embodiment is not limited, and can be one or more. There is no limitation on the number of switches and the types of switches in the switch matrix, and they can be set according to actual conditions. The battery cells of the battery unit in this embodiment are connected to the switch matrix. At the same time, the switch matrix is ​​connected to the first capacitor and the second capacitor, that is, the first capacitor and the second capacitor are connected to the same target battery cell of the battery unit through the switch matrix, so that the same target battery cell is connected to the first capacitor at the first moment and connected to the second capacitor at the second moment. The battery unit is connected to the load, and the current measuring device is arranged on the power supply circuit of the battery unit and the load. The battery unit supplies power to the load, and the current measuring device can measure the current value of the load.

[0046] The first capacitor and the second capacitor are connected to the processor via the in-phase end and the inverting end of the differential amplifier. The first capacitor stores the voltage value of the target battery cell collected at the first moment, and the second capacitor stores the voltage value of the target battery cell collected at the second moment. The connection relationship of the target battery cell at different moments is realized through the in-phase end and the inverting end of the differential amplifier, which is similar to the negative pole connecting the negative pole and the positive pole connecting the positive pole. The amplified data of the difference between the voltage values ​​corresponding to the first moment and the second moment of the target battery cell can be output. In addition, the current measuring device determines the internal resistance value of the target battery cell based on the amplified data of the voltage value difference and the current value difference based on the current value difference collected by the processor. It can be understood that if only the amplification factor of the voltage value difference is divided by the current value difference, the actual internal resistance value of the target battery cell is obtained by dividing by the corresponding amplification factor in the processor.

[0047] The embodiment of the present invention provides a battery measurement circuit based on a battery cell, wherein the battery cell of the battery cell is connected to a switch matrix; the first capacitor and the second capacitor are connected to the same target battery cell of the battery cell via the switch matrix, so that the same target battery cell is connected to the first capacitor at the first moment and connected to the second capacitor at the second moment; the battery cell is connected to a load, and a current measuring device is arranged in the power supply circuit of the battery cell and the load; wherein the battery power supply includes at least one battery cell; the first capacitor and the second capacitor are connected to a processor via the in-phase end and the inverting end of a differential amplifier; the processor is used to determine the internal resistance value of the target battery cell according to the difference between the amplified data of the difference between the voltage values ​​of the target battery cell corresponding to the first moment and the second moment output by the differential amplifier and the current value corresponding to the current measuring device. The present invention measures the actual capacity of the battery by measuring the internal resistance of the battery. Specifically, by measuring the voltage of the battery cell corresponding to different moments, the voltages measured at two different moments are stored in different capacitors, namely the first capacitor and the second capacitor. The voltage values ​​of the two capacitors are transferred to the corresponding capacitor components to measure the voltage values. The first capacitor and the second capacitor are respectively connected to the non-inverting terminal and the inverting terminal of the differential amplifier to amplify the voltage difference of the battery cells and improve the voltage measurement accuracy of each battery cell. Furthermore, the internal resistance of the battery cell can be determined by the difference in current values ​​of the current measuring device at two different times to improve the measurement accuracy of the battery cell. Compared with the traditional battery capacity measurement method, there is no risk of misjudgment due to measuring the battery capacity, and there will be no vicious cycle of smaller capacity and easier discharge.

[0048] In some embodiments, Figure 4 A structural diagram of another battery measurement circuit based on a battery cell provided in an embodiment of the present invention, such as Figure 4 As shown, the switch matrix 2 includes a first switch unit 6;

[0049] The positive electrode of the battery cell passes through the two switches of the first switch unit 6, and is respectively connected to the first ends of the first capacitor C1 and the second capacitor C2; the negative electrode of the battery cell passes through the other two switches of the first switch unit 6, and is respectively connected to the second ends of the first capacitor C1 and the second capacitor C2.

[0050] Specifically, Figure 4Taking the three battery cells (BAT1, BAT2, BAT3) in the example, the positive electrode of the first battery cell BAT1 is connected to the first end of the first capacitor C1 and the first end of the second capacitor C2 through the two switches (SW1 and SW3) of the first switch unit 6. The negative electrode of the first battery cell BAT1 is connected to the second end of the first capacitor C1 and the second end of the second capacitor C2 through the other two switches (SW2 and SW4) of the first switch unit 6. The positive electrode of the battery cell BAT1 is connected to the negative electrode of the battery cell BAT2, and the positive electrode of the battery cell BAT2 is connected to the first end of the first capacitor C1 and the first end of the second capacitor C2 through the two switches (SX1 and SX3) of the first switch unit 6; the negative electrode of the battery cell BAT2 is connected to the second end of the first capacitor C1 and the second end of the second capacitor C2 through the other two switches (SX2 and SX4) of the first switch unit 6. The positive electrode of the battery cell BAT2 is connected to the negative electrode of the battery cell BAT3. The positive electrode of the battery cell BAT3 is connected to the first end of the first capacitor C1 and the first end of the second capacitor C2 through the two switches (SY1 and SY3) of the first switch unit 6; the negative electrode of the battery cell BAT3 is connected to the second end of the first capacitor C1 and the second end of the second capacitor C2 through the other two switches (SY2 and SY4) of the first switch unit 6.

[0051] In some other embodiments, the switch matrix further includes a second switch unit;

[0052] The second ends of the other two switches of the first switch unit connected to the negative electrode of the battery cell correspond to the first ends of the two switches of the second switch unit respectively; the second ends of the two switches of the second switch unit are both connected to the reference ground.

[0053] Specifically, taking three battery cells (BAT1, BAT2, BAT3) as an example, based on the connection relationship of the above embodiment, as shown in FIG. Figure 4 As shown, the negative electrode of any battery cell is connected to the second end of the first capacitor C1 and the second end of the second capacitor C2 through the other two switches of the first switch unit 6, and is also connected to the first ends of the two switches of the second switch unit 7. That is, the two switches (SW2 and SW4) connected to the negative electrode of the battery cell BAT1 are connected to the first ends of the two switches (SW5 and SW6) of the second switch unit 7; the two switches (SX2 and SX4) connected to the negative electrode of the battery cell BAT2 are connected to the first ends of the two switches (SW5 and SW6) of the second switch unit 7; and the two switches (SY2 and SY4) connected to the negative electrode of the battery cell BAT3 are connected to the first ends of the two switches (SW5 and SW6) of the second switch unit 7.

[0054] The number of battery cells can be one or more. In the case of multiple battery cells, the battery cells are connected in series. In addition, the positive electrode of the last battery cell also needs to be connected to the first end of the load, the second end of the load is connected to the first end of the current measuring device, and the second end of the current measuring device is connected to any battery cell. The current measuring device is used to measure the current value of the load. It can be understood that the current measuring device can be at any point on the series path of the battery cell, because the current of any node on the series path is the same, but in the actual application circuit, the specific current measuring device can use a Hall element. The instrument measures the specific current size by measuring the magnetic field strength. It will not be physically connected to the corresponding battery cell series path, but only close to the power line. Other measuring devices can also be used, which are not limited here and can be set according to actual conditions.

[0055] The two switches of the second switch unit 7 are connected to the reference ground. It can be understood that the reference ground realizes the common mode voltage, the average value of the phasor voltage between each conductor and the specified reference point (usually the earth or the frame), or half of the input voltage simultaneously applied between the two measuring terminals and the common terminal of the voltmeter. For example, when the signal is The system will set the reference ground to 0V. For a system with a low impedance, the reference ground is set to 2.5 V. The reference ground provides a low impedance path so that electromagnetic interference (such as noise, surge, etc.) in the circuit can be quickly discharged through the reference ground, reducing interference with the normal operation of the circuit and improving the stability and reliability of the circuit.

[0056] It should be noted that in this embodiment, the switches of the first switch unit corresponding to the negative electrode and the positive electrode of each battery cell are used separately without a shared connection relationship. The switch provided in this embodiment is only a single-pole single-throw switch, and can also be other single-pole multi-throw switches, which is not limited here. If it is a single-pole multi-throw switch, its corresponding connection relationship will also change.

[0057] The specific connection relationship between the switch matrix and the battery cell provided in this embodiment is used to measure the voltage of the battery cell at different times, and store the voltages measured at two different times in different capacitors, namely the first capacitor and the second capacitor. The voltage values ​​of the two capacitors are transferred to the corresponding capacitor components to measure the voltage value.

[0058] In some embodiments, the acquisition of the amplified data is determined by multiplying the amplification factor of the differential amplifier by the difference between the voltage values ​​of the same target battery cell; the amplification factor of the differential amplifier is determined by the number of differential amplifiers connected in series.

[0059] Specifically, the amplified data is obtained by multiplying the amplification factor of the differential amplifier by the difference between the voltage values ​​of any two battery cells. The amplification factor can be determined by the number of differential amplifiers in series, and the corresponding number of series can be determined according to actual conditions and is not limited here.

[0060] In some other embodiments, the gain factor of the differential amplifier is further determined by the resistance relationship between the first resistor and the second resistor of the differential amplifier or by the capacitance relationship between the third capacitor and the fourth capacitor of the differential amplifier.

[0061] Specifically, Figure 5 A structural diagram of a differential amplifier provided by an embodiment of the present invention, such as Figure 5 As shown, it is determined by the internal resistance values ​​of the first resistor R1 and the second resistor R2. Figure 5 Take the three differential amplifiers (A1, A2, A3) as an example, the corresponding ,in, . Figure 6 The structural diagram of another differential amplifier provided by the present invention is as follows: Figure 6 As shown in FIG. , it is determined by the capacitance values ​​of the third capacitor (C3, C3') and the fourth capacitor (C4, C4'). It should be noted that , , and The differential amplifier in this embodiment is a switched capacitor differential amplifier, which is only one embodiment, and may be other differential amplifiers. In addition, in other embodiments, internal resistors or internal capacitors may be combined with the differential amplifier to increase the gain of the differential amplifier.

[0062] The gain factor of the differential amplifier provided in this embodiment is determined based on the number of differential amplifiers connected in series, or based on the internal resistance value or internal capacitance value of the differential amplifier, thereby improving the diversity and flexibility of the differential amplifier gain factor determination method.

[0063] In some embodiments, further comprising a first AD converter;

[0064] The first AD converter is connected to the output terminal of the differential amplifier and is also connected to the processor.

[0065] Specifically, this embodiment also includes an analog-to-digital converter (ADC), such as Figure 2As shown, it is the first AD converter 8; wherein, the accuracy of the first AD converter 8 is not limited, and the corresponding accuracy can be considered based on the cost of the device. The differential amplifier 3 and the processor 4 need to perform data conversion through the first AD converter 8, which is used for the processor 4 to receive the amplification factor of the difference in the voltage value output by the differential amplifier 3, so as to determine the internal resistance value of the target battery cell based on the difference in the current value corresponding to the current measuring device 5. In addition, regarding the ADC converter, it can also be used based on the ADC converter set inside the processor.

[0066] In some embodiments, further comprising a second AD converter;

[0067] The current measuring device is connected to the second AD converter, and is used to measure the current of the battery cell of the power supply circuit and convert it into voltage to output to the second AD converter; the second AD converter is connected to the processor. Specifically, Figure 2 As shown, the processor 4 is used to receive the current value of the load measured by the current measuring device 5 through the second AD converter 9, so that the processor 4 can determine the internal resistance value of the target battery cell based on the difference between the amplified data of the difference between the voltage values ​​corresponding to the target battery cell at the first moment and the second moment output by the differential amplifier 3 and the current value corresponding to the current measuring device 5, thereby improving the measurement accuracy.

[0068] Figure 7 A schematic diagram of step 1 of measuring the internal resistance of a battery cell provided by an embodiment of the present invention; Figure 8 A schematic diagram of step 2 of measuring the internal resistance of a battery cell provided by an embodiment of the present invention; Fig. 9 A schematic diagram of step 3 of measuring the internal resistance of a battery cell provided by an embodiment of the present invention; Fig.10 A schematic diagram of step 4 of measuring the internal resistance of a battery cell provided by an embodiment of the present invention. Figures 7 to 10 As shown, step 1, turn off all switches SW1 to SW4 of the first switch unit 6; step 2, turn on SW1 and SW2 so that the voltage of the battery cell BAT1 is stored in the first capacitor C1; step 3, change the load LOAD1 so that the current of the load LOAD1 changes, turn on switches SW3 and SW4 so that the voltage of the battery cell BAT1 after the current change is stored in the second capacitor C2; step 4, turn off switches SW1, SW2, SW3 and SW4, turn on switches SW5 and SW6, so that the voltage difference between the first capacitor C1 and the second capacitor C2 passes through the differential amplifier, and the voltage difference is in the current difference, and the internal resistance value of the battery cell BAT1 is obtained, and its accuracy is improved. In addition, the accuracy can be obtained through experiments. It should be noted that before step 3 and step 4, after step 2, the switch state needs to return to the state of step 1 before the switch opening work of step 3 can be performed. Similarly, after step 3, the switch state needs to return to the state of step 1 before the switch opening work of step 4 can be performed.

[0069] Furthermore, the present invention also provides a battery chip, comprising the above-mentioned battery measurement circuit based on the battery cell.

[0070] It should be noted that the battery chip corresponding to this embodiment can be applicable to rechargeable batteries, such as lead-acid batteries, etc., without limitation here, and can also be applicable to other batteries, which can be set according to actual conditions. The battery chip in this embodiment can also be used to troubleshoot battery cell failure scenarios of battery units.

[0071] For an introduction to a battery chip provided by the present invention, please refer to the above method embodiment, which will not be described in detail herein. The battery chip has the same beneficial effects as the above battery measurement circuit based on the battery unit.

[0072] Furthermore, the present invention also provides a battery measurement method based on a battery cell, which is applied to the above-mentioned battery measurement circuit based on a battery cell, and the method includes:

[0073] Determine the target battery cell;

[0074] receiving amplified data of the difference between the voltage values ​​determined by the voltage values ​​stored in the first capacitor and the second capacitor at the first moment and the second moment of the target battery cell outputted from the output end of the differential amplifier; wherein the voltage values ​​corresponding to the first capacitor and the second capacitor are obtained by the target battery cell turning on the switches of the correspondingly connected switch matrix and storing them at the first moment and the second moment;

[0075] The first moment and the second moment sent by the receiving current measuring device correspond to the current value of the target battery cell respectively;

[0076] The current value difference is determined according to the current values ​​corresponding to the first moment and the second moment; and the internal resistance value of the target battery cell is determined according to the amplified data of the voltage value difference and the current value difference.

[0077] Specifically, this embodiment determines the target battery cell, and based on the connection relationship between the differential amplifier, the switch matrix, the first capacitor and the second capacitor, receives the amplified data of the voltage value difference determined by the voltage values ​​stored in the first capacitor and the second capacitor at the first moment and the second moment of the target battery cell outputted from the output end of the differential amplifier; wherein the voltage values ​​corresponding to the first capacitor and the second capacitor are obtained by the target battery cell turning on the switches of the correspondingly connected switch matrix and storing them at the first moment and the second moment respectively. Then, the current value of the corresponding target battery cell sent by the current measuring device at the first moment and the second moment is received, and the current value difference is determined according to the current values ​​corresponding to the first moment and the second moment; and the internal resistance value of the target battery cell is determined according to the amplified data of the voltage value difference and the current value difference.

[0078] For an introduction to a battery measurement method based on a battery cell provided by the present invention, please refer to the above method embodiment, and the present invention will not be repeated here. It has the same beneficial effects as the above battery measurement circuit based on a battery cell.

[0079] The above is a detailed introduction to a battery measurement circuit, a battery chip and a battery measurement method based on a battery cell provided by the present invention. The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referenced to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the present invention.

[0080] It should also be noted that, in this specification, relational terms such as first and second, etc. are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

Claims

1. A battery measurement circuit based on a battery cell, characterized in that: The battery measurement circuit includes a switch matrix, a first capacitor, a second capacitor and a differential amplifier; The switch matrix is ​​connected to the battery cell of the battery unit; the first capacitor and the second capacitor are correspondingly connected to the same target battery cell of the battery unit through the switch matrix, so that the same target battery cell is connected to the first capacitor at the first moment and connected to the second capacitor at the second moment; the battery unit is connected to the load, and the current measuring device is arranged in the power supply circuit of the battery unit and the load; wherein the battery unit includes at least one battery cell; The first capacitor and the second capacitor are connected to the processor via the non-inverting terminal and the inverting terminal of the differential amplifier respectively; the processor is used to determine the internal resistance value of the target battery cell based on the difference between the amplified data of the difference between the voltage values ​​of the target battery cell corresponding to the first moment and the second moment output by the differential amplifier and the difference between the current values ​​corresponding to the current measuring device.

2. The battery measurement circuit based on a battery cell according to claim 1, characterized in that: The switch matrix comprises a first switch unit; The positive electrode of the battery cell passes through the two switches of the first switch unit, and is respectively connected to the first ends of the first capacitor and the second capacitor; the negative electrode of the battery cell passes through the other two switches of the first switch unit, and is respectively connected to the second ends of the first capacitor and the second capacitor.

3. The battery measurement circuit based on a battery cell according to claim 1 or 2, characterized in that: The amplified data is obtained by multiplying the amplification factor of the differential amplifier by the difference between the voltage values ​​of the same target battery cell; the amplification factor of the differential amplifier is determined by the number of series-connected differential amplifiers.

4. The battery measurement circuit based on the battery cell according to claim 3, characterized in that: The gain of the differential amplifier is also determined by the resistance relationship between the first resistor and the second resistor of the differential amplifier or by the capacitance relationship between the third capacitor and the fourth capacitor of the differential amplifier.

5. The battery measurement circuit based on a battery cell according to claim 3, characterized in that: Also includes a first AD converter; The first AD converter is connected to the output end of the differential amplifier and is also connected to the processor.

6. The battery measurement circuit based on a battery cell according to claim 5, characterized in that: Also including a second AD converter; The current measuring device is connected to the second AD converter and is used to measure the current of the battery cell of the power supply circuit and convert it into voltage to output to the second AD converter; the second AD converter is connected to the processor.

7. A battery chip, characterized in that: A battery measurement circuit based on a battery cell comprising any one of claims 1 to 6.

8. A battery measurement method based on a battery cell, characterized in that: Applied to the battery measurement circuit based on the battery cell according to claim 1, the method comprises: Determine the target battery cell; receiving amplified data of a voltage value determined by a voltage value stored in a first capacitor and a second capacitor at a first moment and a second moment of a target battery cell outputted from an output terminal of a differential amplifier; wherein the voltage values ​​corresponding to the first capacitor and the second capacitor are obtained by the target battery cell turning on switches of a correspondingly connected switch matrix and storing them at the first moment and the second moment; The first moment and the second moment sent by the receiving current measuring device correspond to the current value of the target battery cell respectively; The difference between the current values ​​is determined according to the current values ​​corresponding to the first moment and the second moment; and the internal resistance value of the target battery cell is determined according to the amplified data of the difference between the voltage values ​​and the difference between the current values.

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