A method for measuring the battery reserve capacity of a battery and a battery testing device

Abstract

The embodiment of the present invention relates to the field of battery detection technology, and provides a method for measuring the battery reserve capacity of a battery and a battery detection device. The method for measuring the battery reserve capacity of a battery is applied to a battery detection device, and the battery detection device is electrically connected to the battery through a Kelvin connector. The method includes: sending an input signal to the battery to control the discharge of the battery, obtaining an output signal of the battery for the input signal during the input duration of the input signal; determining a target battery parameter according to the output signal; obtaining a battery capacity table, the battery capacity table including a corresponding relationship between battery parameters and battery reserve capacity; and determining the battery reserve capacity corresponding to the target battery parameter according to the battery capacity table and the target battery parameter. In the above manner, the embodiment of the present invention can reduce the measurement time of the battery reserve capacity of the battery and improve the measurement efficiency.

Description

[Technical field]

[0001] The embodiments of the present invention relate to the technical field of battery detection, and in particular to a method for measuring the battery reserve capacity of a battery and a battery detection device. [Background technology]

[0002] Traditional cars are equipped with batteries to provide power for starting the car engine and on-board electrical equipment. The reserve capacity (RC, also known as the remaining power or remaining capacity) of a battery refers to the time (in minutes) required for the battery to discharge to 10.5V at a current of 25A, indicating the ability of the battery to continuously provide 25A current for electrical equipment such as ignition and lighting as the only energy source when the car charging system fails. At present, the existing technology mostly uses constant current discharge equipment to discharge the battery to 10.5V at a constant current of 25A, and measures the time of the above process to achieve the measurement of the battery reserve capacity of the battery. However, the measurement time of the above measurement method is relatively long, which reduces the measurement efficiency of the battery reserve capacity of the battery. [Summary of the invention]

[0003] The embodiments of the present invention aim to provide a method for measuring the battery reserve capacity of a storage battery and a battery detection device, which can reduce the measurement time of the battery reserve capacity of the storage battery and improve the measurement efficiency.

[0004] To solve the above technical problems, the embodiments of the present invention provide the following technical solutions:

[0005] An embodiment of the present invention provides a method for measuring the battery reserve capacity of a battery, which is applied to a battery detection device, wherein the battery detection device is electrically connected to the battery through a Kelvin connector, and the method includes:

[0006] Sending an input signal to the battery to control the discharge of the battery, and obtaining an output signal fed back by the battery in response to the input signal within the input duration of the input signal;

[0007] determining a target battery parameter according to the output signal;

[0008] Obtaining a battery capacity table, wherein the battery capacity table includes a corresponding relationship between battery parameters and battery reserve capacity;

[0009] According to the battery capacity table and the target battery parameter, a battery reserve capacity corresponding to the target battery parameter is determined.

[0010] In some embodiments, sending an input signal to the battery to control the discharge of the battery includes:

[0011] An input signal is sent to the battery at least twice to control the discharge of the battery.

[0012] In some embodiments, the sending of input signals to the battery at least twice to control the discharge of the battery includes:

[0013] An input signal is sent to the battery at least twice at a preset frequency to control the discharge of the battery.

[0014] In some embodiments, the interval between at least two transmissions of the input signal is random.

[0015] In some embodiments, the sending of input signals to the battery at least twice to control the discharge of the battery includes:

[0016] An input signal is sent to the battery at least twice to control the battery to discharge up to a preset number of times.

[0017] In some embodiments, the input durations of the input signals sent at least twice are the same, or at least one of the input durations of the input signals sent at least twice is different from the other input durations.

[0018] In some embodiments, the duration unit of the input duration is milliseconds (ms).

[0019] In some embodiments, the input signal is a discharge current of the battery, and the output signal is an open circuit voltage of the battery fed back in response to the discharge current within the input time period.

[0020] In some embodiments, determining the target battery parameter according to the output signal includes:

[0021] detecting a set of battery parameters of the battery each time the battery is discharged according to the output signal;

[0022] An optimal battery parameter is selected from at least two groups of voltage parameters as the target battery parameter.

[0023] In some embodiments, the battery parameters include a maximum voltage, a minimum voltage, and a voltage drop slope of the battery each time it is discharged.

[0024] In some embodiments, the step of selecting an optimal voltage parameter from at least two sets of battery parameters as the target battery parameter comprises:

[0025] Selecting a maximum voltage with the largest voltage among the at least two groups of battery parameters as a target maximum voltage;

[0026] Selecting a minimum voltage with the smallest voltage among the at least two groups of battery parameters as a target minimum voltage;

[0027] The target maximum voltage, the target minimum voltage, and the target voltage drop slope corresponding to the target maximum voltage and the target minimum voltage are used as optimal battery parameters.

[0028] In some embodiments, the battery capacity table includes several types of battery reserve capacities and several groups of voltage parameters under each of the battery reserve capacities, each group of voltage parameters includes several test voltages and battery parameters obtained by discharging the battery under each test voltage, wherein the several types of battery reserve capacities are spaced apart by a preset capacity, and the several test voltages are spaced apart by a preset voltage.

[0029] In some embodiments, determining the battery reserve capacity corresponding to the target battery parameter according to the battery capacity table and the target battery parameter includes:

[0030] inputting the target battery parameter into the battery capacity table;

[0031] A battery reserve capacity matching the target voltage drop slope is searched in the battery capacity table, and the battery reserve capacity is used as the battery reserve capacity of the storage battery.

[0032] In some embodiments, the voltage drop slope of each battery parameter corresponds to a slope matching range, and searching the battery capacity table for a battery reserve capacity that matches the target voltage drop slope, and using the battery reserve capacity as the battery reserve capacity of the storage battery, includes:

[0033] Determining whether the target pressure drop slope falls within a slope matching range of an effective pressure drop slope;

[0034] If so, the battery reserve capacity corresponding to the effective voltage drop slope is used as the battery reserve capacity of the storage battery.

[0035] The embodiment of the present invention further provides a battery detection device, wherein the battery detection device is electrically connected to a storage battery via a Kelvin connector, and the battery detection device comprises:

[0036] a discharge circuit, electrically connected to the battery through the Kelvin connector, and used for sending an input signal to the battery to control the discharge of the battery;

[0037] a voltage sampling circuit, electrically connected to the storage battery through the Kelvin connector, and used for sampling an output signal fed back by the storage battery in response to the input signal within the input duration of the input signal to obtain a sampled voltage;

[0038] A controller is electrically connected to the discharge circuit and the voltage sampling circuit, respectively, and is used to control the discharge circuit so that the discharge circuit sends an input signal to the battery, determines a target battery parameter according to the sampled voltage, and obtains a battery capacity table, wherein the battery capacity table includes a correspondence between battery parameters and battery reserve capacity, and determines a battery reserve capacity corresponding to the target battery parameter according to the battery capacity table and the target battery parameter.

[0039] In some embodiments, the input signal is a discharge current of the battery, and the output signal is an open circuit voltage of the battery fed back in response to the discharge current within the input time period.

[0040] In some embodiments, the discharge circuit comprises:

[0041] a switch circuit, electrically connected to the controller and electrically connected to the storage battery through the Kelvin connector, and configured to trigger the sending of a discharge current to the storage battery and generate a trigger signal when the controller controls the switch circuit to be in an on state;

[0042] The first signal processing circuit is electrically connected to the controller and the switch circuit respectively, and is used to process the voltage signal sent by the controller and the trigger signal sent by the switch circuit, and output a driving signal to control the magnitude of the discharge current. In some embodiments, the switch circuit includes:

[0043] a first switch, electrically connected to the controller and the first signal processing circuit respectively, and electrically connected to the negative electrode of the battery through the Kelvin connector, and used for controlling the closing or disconnection of the discharge circuit between the controller and the battery according to the control signal sent by the controller, generating a trigger signal, and sending the trigger signal to the first signal processing circuit;

[0044] The second switch is electrically connected to the first switch and the first signal processing circuit respectively, and is electrically connected to the positive electrode of the battery through the Kelvin connector, and is used to control the magnitude of the discharge current of the discharge circuit according to the drive signal.

[0045] In some embodiments, the first switch includes a first PMOS tube, a gate of the first PMOS tube is electrically connected to the controller, a source of the first PMOS tube is electrically connected to the negative electrode of the battery through the Kelvin connector, and a drain of the first PMOS tube is electrically connected to the second switch and the first signal processing circuit.

[0046] In some embodiments, the second switch includes a second PMOS tube, a gate of the second PMOS tube is electrically connected to the first signal processing circuit, a source of the second PMOS tube is electrically connected to a drain of the first PMOS tube and the first signal processing circuit, and a drain of the second PMOS tube is electrically connected to the positive electrode of the battery through the Kelvin connector.

[0047] In some embodiments, the first signal processing circuit includes a first operational amplifier, a non-inverting input terminal of the first operational amplifier is electrically connected to the controller, an inverting input terminal of the first operational amplifier is electrically connected to the drain of the first PMOS tube and the source of the second PMOS tube, and an output terminal of the first operational amplifier is electrically connected to the gate of the second PMOS tube.

[0048] In some embodiments, the discharge circuit further includes a unidirectional conduction circuit, which is electrically connected between the second switch and the positive electrode of the battery to prevent the discharge current from flowing back to the positive electrode of the battery.

[0049] In some embodiments, the voltage sampling circuit includes:

[0050] a second signal processing circuit, electrically connected to the battery through the Kelvin connector, for performing signal processing on the open circuit voltage of the battery;

[0051] The voltage divider circuit is electrically connected to the second signal processing circuit and the controller respectively, and is used to divide the output voltage of the second signal processing circuit to obtain a sampling voltage, so that the controller determines the target battery parameter according to the sampling voltage.

[0052] In some embodiments, the second signal processing circuit includes a second operational amplifier, a non-inverting input terminal of the second operational amplifier is electrically connected to the positive electrode of the battery through the Kelvin connector, an inverting input terminal of the second operational amplifier is electrically connected to the negative electrode of the battery through the Kelvin connector, and an output terminal of the second operational amplifier is electrically connected to the voltage divider circuit.

[0053] In some embodiments, the voltage divider circuit includes a first resistor and a second resistor;

[0054] One end of the first resistor is electrically connected to the output end of the second operational amplifier, the other end of the first resistor is electrically connected to the controller and one end of the second resistor; the other end of the second resistor is grounded.

[0055] The beneficial effects of the present invention are as follows: compared with the prior art, the embodiment of the present invention provides a method for measuring the battery reserve capacity of a storage battery and a battery detection device, by sending an input signal to the storage battery to control the discharge of the storage battery, obtaining an output signal of the storage battery for the input signal feedback within the input duration of the input signal, determining the target battery parameter according to the output signal, obtaining a battery capacity table, the battery capacity table including the corresponding relationship between the battery parameter and the battery reserve capacity, and determining the battery reserve capacity corresponding to the target battery parameter according to the battery capacity table and the target battery parameter. Therefore, the embodiment of the present invention obtains the target battery parameter by controlling the storage battery to discharge at least once, and measures the battery reserve capacity of the storage battery according to the target battery parameter and the battery capacity table including the corresponding relationship between the battery parameter and the battery reserve capacity, thereby reducing the measurement time of the battery reserve capacity of the storage battery and improving the measurement efficiency.

Brief Description of the Drawings

[0056] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0057] Figure 1 A schematic diagram of the circuit structure of a battery detection device provided by an embodiment of the present invention;

[0058] Figure 2 for Figure 1 The circuit structure diagram of the discharge circuit and the voltage sampling circuit shown;

[0059] Figure 3 A circuit connection diagram of a battery detection device provided by an embodiment of the present invention;

[0060] Figure 4 A method flow chart of a method for measuring the battery reserve capacity of a battery provided by an embodiment of the present invention. [Specific implementation method]

[0061] In order to facilitate the understanding of the present application, the present application is described in more detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that when an element is described as "connected" to another element, it can be directly connected to the other element, or there can be one or more intermediate elements therebetween. In addition, the terms "first", "second", etc. are used only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0062] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used in this specification includes any and all combinations of one or more of the related listed items.

[0063] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0064] See also Figure 1 , is a schematic diagram of the circuit structure of a battery detection device provided by an embodiment of the present invention. Figure 1 As shown, the battery testing device 100 is electrically connected to the battery 200 via a Kelvin connector (not shown), and the battery testing device 100 includes a discharge circuit 10 , a voltage sampling circuit 20 and a controller 30 .

[0065] like Figure 2 As shown, the Kelvin connector includes a B+ connection line, a B- connection line, an S+ connection line, and an S- connection line. Among them, the B+ connection line and the S+ connection line are both electrically connected to the positive electrode of the battery 200, the B- connection line and the S- connection line are both electrically connected to the negative electrode of the battery 200, the B+ connection line and the B- connection line are used to separate the discharge current between the two electrodes of the battery 200, and the S+ connection line and the S- connection line are used to separate the open circuit voltage between the two electrodes of the battery 200. The Kelvin four-wire detection is realized through the Kelvin connector, eliminating the impedance of the wiring and the contact resistance. The contact resistance refers to the resistance when the current flows through the positive electrode of the battery 200 or the negative electrode of the battery 200 when the battery detection device 100 and the battery 200 form a discharge circuit.

[0066] The discharge circuit 10 is electrically connected to the battery 200 via a Kelvin connector, and is used to send an input signal to the battery 200 to control the discharge of the battery 200 .

[0067] In the embodiment of the present invention, the input signal is the discharge current of the battery 200. When the discharge circuit 10 sends the discharge current to the battery 200, the discharge circuit 10 is in the on state, and the discharge circuit 10 and the battery 20 form a discharge loop, triggering the battery 200 to start discharging, that is, the input signal can be used to control the discharge of the battery 200.

[0068] Please also read Figure 2 The discharge circuit 10 includes a switch circuit 101 and a first signal processing circuit 102 .

[0069] The switch circuit 101 is electrically connected to the controller 30 and is electrically connected to the battery 200 through a Kelvin connector, and is used to trigger the sending of a discharge current to the battery 200 and generate a trigger signal when the controller 30 controls the switch circuit 101 to be in an on state.

[0070] Furthermore, the switch circuit 101 includes a first switch 1011 and a second switch 1012 .

[0071] The first switch 1011 is electrically connected to the controller 30 and the first signal processing circuit 102 respectively, and is electrically connected to the negative pole of the battery 200 through a Kelvin connector. It is used to control the closing or disconnection of the discharge circuit between the controller 30 and the battery 200 according to the control signal sent by the controller 30, generate a trigger signal, and send the trigger signal to the first signal processing circuit 102.

[0072] The first switch 1011 is electrically connected to one end of the B-connection line, and the other end of the B-connection line is electrically connected to the negative electrode of the battery BAT1.

[0073] See also Figure 3 The first switch 101 includes a first PMOS tube Q1, the gate of the first PMOS tube Q1 is electrically connected to the controller 30 (I / O port of the single-chip computer U3), the source of the first PMOS tube Q1 is electrically connected to the negative electrode of the battery BAT1 through a Kelvin connector (B-connection line), and the drain of the first PMOS tube Q1 is electrically connected to the second switch 1012 and the first signal processing circuit 102. When the first PMOS tube Q1 is turned on, the drain of the first PMOS tube Q1 is pulled to a low level, a trigger signal is generated, and the low-level trigger signal is sent to the first signal processing circuit 102.

[0074] The second switch 1012 is electrically connected to the first switch 1011 and the first signal processing circuit 102 respectively, and is electrically connected to the positive electrode of the battery 200 through a Kelvin connector, and is used to control the discharge current of the discharge circuit according to the drive signal output by the first signal processing circuit 102.

[0075] The second switch 1012 is electrically connected to one end of the B+ connection line, and the other end of the B+ connection line is electrically connected to the positive electrode of the battery BAT1.

[0076] like Figure 3As shown, the second switch 1012 includes a second PMOS tube Q2, the gate of the second PMOS tube Q2 is electrically connected to the first signal processing circuit 102, the source of the second PMOS tube Q2 is electrically connected to the drain of the first PMOS tube and the first signal processing circuit 102, and the drain of the second PMOS tube Q2 is electrically connected to the positive electrode of the battery BAT1 through a Kelvin connector (B+ connection line). When the first PMOS tube Q1 is turned on, the drain of the first PMOS tube Q1 is pulled to a low level, a trigger signal is generated, and the low-level trigger signal is sent to the first signal processing circuit 102, and the first signal processing circuit 102 generates a drive signal, which acts on the gate of the second PMOS tube Q2 to control the second PMOS tube Q2 to turn on. When the second PMOS tube Q2 is turned on, the drain current of the second PMOS tube Q2 depends on the gate voltage of the second PMOS tube Q2. The drain current of the second PMOS tube Q2 is equal to the discharge current of the discharge loop between the positive electrode of the battery BAT1, the second PMOS tube Q2, the first PMOS tube Q1 and the negative electrode of the battery BAT1.

[0077] The first signal processing circuit 102 is electrically connected to the controller 30 and the switch circuit 101 respectively, and is used to process the voltage signal sent by the controller 30 and the trigger signal sent by the switch circuit 101, and output a driving signal to control the size of the discharge current.

[0078] like Figure 3 As shown, the first signal processing circuit 102 includes a first operational amplifier U1, the non-inverting input terminal of the first operational amplifier U1 is electrically connected to the controller 30 (DAC port of the single-chip computer U3), the inverting input terminal of the first operational amplifier U1 is electrically connected to the drain of the first PMOS tube Q1 and the source of the second PMOS tube Q2, and the output terminal of the first operational amplifier U1 is electrically connected to the gate of the second PMOS tube Q2. The non-inverting input terminal of the first operational amplifier U1 is used to receive the voltage signal sent by the controller 30, and the inverting input terminal of the first operational amplifier U1 is used to receive the trigger signal output by the first PMOS tube Q1. The first operational amplifier U1 performs signal processing on the voltage signal and the trigger signal, and outputs a driving signal. Therefore, the size of the driving signal is related to the size of the voltage signal, and the discharge current of the discharge circuit between the positive electrode of the battery BAT1, the second PMOS tube Q2, the first PMOS tube Q1 and the negative electrode of the battery BAT1 can be adjusted by adjusting the voltage signal sent by the controller 30.

[0079] In some embodiments, the discharge circuit 10 further includes a unidirectional conduction circuit 103 , which is electrically connected between the second switch 1012 and the positive electrode of the battery 200 to prevent the discharge current from flowing back to the positive electrode of the battery 200 .

[0080] One end of the unidirectional conductive circuit 103 is electrically connected to the second switch 1012 , and the other end of the unidirectional conductive circuit 103 is electrically connected to one end of the B+ connection line.

[0081] like Figure 3 As shown, the unidirectional conduction circuit 103 includes a diode D1, the anode of the diode D1 is electrically connected to the positive electrode of the battery BAT1, and the cathode of the diode D1 is electrically connected to the drain of the second PMOS tube Q2. By utilizing the unidirectional conductivity of the diode, in the external circuit of the battery BAT1, the discharge current always flows from the positive electrode of the battery BAT1 through the second PMOS tube Q2 and the first PMOS tube Q1, and finally flows back to the negative electrode of the battery BAT1, thereby preventing the current from flowing back and burning the battery BAT1.

[0082] The voltage sampling circuit 20 is electrically connected to the battery 200 via a Kelvin connector, and is used to sample the output signal of the battery 200 fed back in response to the input signal within the input duration of the input signal to obtain a sampled voltage.

[0083] The output signal is the open circuit voltage of the battery 200 fed back for the discharge current during the input duration. The open circuit voltage is the voltage between the positive electrode of the battery 200 and the negative electrode of the battery 200 when the battery 200 is discharged. The voltage sampling circuit 20 samples the open circuit voltage of the battery 200 through the S+ connection line and the S- connection line of the Kelvin connector.

[0084] Please refer again Figure 2 The voltage sampling circuit 20 includes a second signal processing circuit 201 and a voltage dividing circuit 202 .

[0085] The second signal processing circuit 201 is electrically connected to the battery 200 via a Kelvin connector, and is used to perform signal processing on the open circuit voltage of the battery 200 .

[0086] The second signal processing circuit 201 is electrically connected to one end of the S+ connection line and one end of the S- connection line respectively, the other end of the S+ connection line is electrically connected to the positive electrode of the battery BAT1, and the other end of the S- connection line is electrically connected to the negative electrode of the battery BAT1.

[0087] like Figure 3 As shown, the second signal processing circuit 201 includes a second operational amplifier U2, the non-inverting input terminal of the second operational amplifier U2 is electrically connected to the positive electrode of the battery BAT1 through a Kelvin connector (S+ connection line), the inverting input terminal of the second operational amplifier U2 is electrically connected to the negative electrode of the battery BAT1 through a Kelvin connector (S- connection line), and the output terminal of the second operational amplifier U2 is electrically connected to the voltage divider circuit 202.

[0088] The voltage divider circuit 202 is electrically connected to the second signal processing circuit 201 and the controller 30 respectively, and is used to divide the output voltage of the second signal processing circuit 201 to obtain a sampling voltage, so that the controller 30 determines the target battery parameter according to the sampling voltage.

[0089] like Figure 3 As shown, the voltage divider circuit 202 includes a first resistor R1 and a second resistor R2. One end of the first resistor R1 is electrically connected to the output end of the second operational amplifier U2, and the other end of the first resistor R1 is electrically connected to the controller 30 (ADC port of the single-chip computer U3) and one end of the second resistor R2; the other end of the second resistor R2 is grounded.

[0090] The controller 30 is electrically connected to the discharge circuit 10 and the voltage sampling circuit 20, respectively, and is used to control the discharge circuit 10 so that the discharge circuit 10 sends an input signal to the battery 200, determines the target battery parameters according to the sampled voltage, and obtains a battery capacity table, the battery capacity table includes a correspondence between the battery parameters and the battery reserve capacity, and determines the battery reserve capacity corresponding to the target battery parameters according to the battery capacity table and the target battery parameters.

[0091] like Figure 3 As shown, the controller 30 includes a single-chip microcomputer U3, which can be a 51 series, Arduino series, STM32 series, etc. The single-chip microcomputer U3 includes an I / O port, a DAC port, and an ADC port. Among them, the I / O port of the single-chip microcomputer U3 is electrically connected to the gate of the first PMOS tube Q1, the DAC port of the single-chip microcomputer U3 is electrically connected to the non-inverting input terminal of the first operational amplifier U1, and the ADC port of the single-chip microcomputer U3 is electrically connected to the connection node between the first resistor R1 and the second resistor R2.

[0092] In some embodiments, the controller 30 can also be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), an ARM (Acorn RISC Machine) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination of these components; it can also be any traditional processor, controller, microcontroller or state machine; it can also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors combined with a DSP core, or any other such configuration.

[0093] In summary, the working process of the battery testing device 100 is as follows:

[0094] (1) When the I / O port of the single-chip computer U3 outputs a high-level signal and the DAC port of the single-chip computer U3 outputs a voltage signal, the high-level signal acts on the gate of the first PMOS transistor Q1, and the conduction condition of the first PMOS transistor Q1 is met. The first PMOS transistor Q1 is turned on, and the drain voltage of the first PMOS transistor Q1 is pulled down, that is, the inverting input terminal of the first operational amplifier U1 is at a low level. The first operational amplifier U1 processes the voltage signal inputted at the non-inverting input terminal and the low-level signal inputted at the inverting input terminal to obtain a driving signal, wherein the magnitude of the driving signal is related to the magnitude of the voltage signal. The driving signal acts on the gate of the second PMOS transistor Q2, and the conduction condition of the second PMOS transistor Q2 is met. The second PMOS transistor Q2 is turned on. At this time, a discharge circuit is formed between the positive electrode of the battery BAT1, the diode D1, the second PMOS transistor Q2, the first PMOS transistor Q1 and the negative electrode of the battery BAT1, and the battery BAT1 is discharged with a constant discharge current, wherein the magnitude of the discharge current is related to the magnitude of the driving signal.

[0095] When the battery BAT1 is discharged at a constant discharge current, the battery BAT1 generates an open circuit voltage, the in-phase input terminal of the second operational amplifier U2 is electrically connected to the positive electrode of the battery BAT1, and the inverting input terminal of the second operational amplifier U2 is electrically connected to the negative electrode of the battery BAT1. The second operational amplifier U2 performs signal processing on the open circuit voltage, and then performs voltage division processing through the voltage divider circuit composed of the first resistor R1 and the second resistor R2 to obtain a sampled voltage, and sends the sampled voltage to the ADC port of the single-chip microcomputer U3. The single-chip microcomputer U3 detects the maximum voltage and minimum voltage of the open circuit voltage during this discharge process based on the sampled voltage, and calculates the voltage drop slope based on the maximum voltage, the minimum voltage and the discharge time of the battery BAT1, and stores the battery parameters of this group.

[0096] (2) The I / O port of the single-chip computer U3 outputs a low-level signal, which acts on the gate of the first PMOS transistor Q1. The conduction condition of the first PMOS transistor Q1 is not met, and the first PMOS transistor Q1 is turned off, cutting off the discharge circuit of the battery BAT1, and the battery BAT1 stops discharging.

[0097] (3) Repeat steps (1) and (2) to control the battery to perform intermittent constant current discharge to obtain several sets of battery parameters. The single chip microcomputer U3 determines the target battery parameters from the several sets of battery parameters according to a preset algorithm, so that the single chip microcomputer U3 determines the battery reserve capacity corresponding to the target battery parameters according to the target battery parameters and the battery capacity table.

[0098] The above product can execute the method provided by the embodiment of the present invention, and has the functional modules and beneficial effects corresponding to the execution method. For technical details not described in detail in this embodiment, please refer to the method provided by the embodiment of the present invention.

[0099] See also Figure 4 , is a flow chart of a method for measuring the battery reserve capacity of a battery provided by an embodiment of the present invention. Figure 4 As shown, the method S400 for measuring the battery reserve capacity of a battery is applied to the battery testing device 100 described in any of the above embodiments, the battery testing device 100 is electrically connected to the battery 200 through a Kelvin connector, and the method includes:

[0100] Step S41: sending an input signal to the battery to control the discharge of the battery, and obtaining an output signal fed back by the battery in response to the input signal within the input duration of the input signal.

[0101] It can be understood that the battery detection device can send at least one input signal to the battery. Each time an input signal is sent to the battery, the battery continues to discharge within the input duration of the input signal and returns an output signal to the battery detection device. When the input duration of the input signal ends, the battery stops discharging and stops returning output signals to the battery detection device.

[0102] In some embodiments, sending an input signal to the battery to control the discharge of the battery includes sending an input signal to the battery at least twice to control the discharge of the battery.

[0103] As one of the embodiments of the present invention, sending an input signal to the battery at least twice to control the discharge of the battery includes: sending an input signal to the battery at least twice at a preset frequency to control the discharge of the battery.

[0104] The input signal of the preset frequency may be generated by means of a timer interrupt, that is, the sending intervals of at least two sending of the input signal are equal.

[0105] As one of the embodiments of the present invention, the interval between at least two times of sending the input signal is random, that is, the length of the sending interval is not predetermined, and can be the same or different. For example, the randomly generated input signal can be generated by a preset algorithm.

[0106] As one of the embodiments of the present invention, sending an input signal to the battery at least twice to control the battery to discharge includes: sending an input signal to the battery at least twice to control the battery to discharge up to a preset number of times.

[0107] Specifically, the number of times the input signal is sent to the battery is detected by means of a counter to determine whether the number of discharges of the battery reaches a preset number. If so, the input signal is stopped from being sent to the battery, thereby achieving at least two times of sending the input signal to the battery to control the battery to discharge until the preset number of times.

[0108] The preset number of times can be set according to the rated parameters of the battery, for example, by presetting the mathematical relationship between the rated parameters and the preset number of times, detecting the rated parameters of the battery, and determining the preset number of times according to the rated parameters of the battery and the mathematical relationship between the rated parameters and the preset number of times. When the rated current of the battery is large, the value of the preset number of times can be reduced to reduce the heat generated by the discharge of the battery. The preset number of times can also be manually set according to historical experience values. For example, for a 100RC battery, when an input signal is sent to the battery to control the battery discharge up to 20 times, the battery reserve capacity measurement result of the battery is equal to 100RC for a total of 20 times, when an input signal is sent to the battery to control the battery discharge up to 15 times, the battery reserve capacity measurement result of the battery is equal to 100RC for a total of 14 times, when an input signal is sent to the battery to control the battery discharge up to 10 times, the battery reserve capacity measurement result of the battery is equal to 100RC for a total of 8 times, then the preset number of times can be set to 20 times.

[0109] As one of the embodiments of the present invention, the input durations of the input signals sent at least twice are the same, or at least one of the input durations of the input signals sent at least twice is different from the other input durations.

[0110] In the embodiment of the present application, during one discharge process, the continuous discharge time of the battery is equal to the input duration of the input signal, that is, at the start of the input signal, the battery is triggered to start discharging, and at the end of the input signal, the battery is triggered to end discharging. When the input signal is sent to the battery at least twice, the battery corresponds to at least two discharge processes, and the continuous discharge time of each battery can be the same or different, all depending on the input duration of the input signal sent to the battery by the battery detection device each time.

[0111] Optionally, the duration unit of the input duration is milliseconds, such as the input duration is 150ms.

[0112] The embodiment of the present application can determine the reserve capacity of the battery by inputting a signal to the battery in a relatively short period of time to guide the battery to discharge, thereby saving the time for measuring the reserve capacity of the battery and improving the user experience.

[0113] During the input duration of the input signal, the battery detection device controls the battery to discharge, and the battery discharge generates heat. According to the heat formula Q=I^2Rt, when the battery is discharged at a constant high current, the longer the input duration, the higher the heat generated by the battery discharge. Therefore, by setting a sending interval between at least two input signal transmissions and limiting the input duration to the ms level, the battery is controlled to achieve intermittent high current discharge to avoid the problem of a large amount of heat generated by continuous discharge of the battery.

[0114] In an embodiment of the present invention, the input signal is the discharge current of the battery, and the output signal is the open circuit voltage of the battery for the discharge current feedback within the input time. Among them, by setting the value of the target discharge current in the battery detection device, and outputting a voltage signal according to the target discharge current and the current-voltage relationship table pre-stored in the battery detection device, the discharge current of the battery is controlled to be equal to the target discharge current, that is, the current of the discharge circuit of the battery detection device and the battery is equal to the target discharge current. Of course, according to the detection requirements, the input signal of the battery and the output signal of the battery can also exist in other forms, such as the input signal is a load, or the input signal is a voltage, the output signal is a current, etc., which are not limited here. In some embodiments, before sending an input signal to the battery to control the discharge of the battery, the method also includes: initializing the battery detection device.

[0115] Step S42: determining target battery parameters according to the output signal.

[0116] Determining the target battery parameters according to the output signal includes: detecting a set of battery parameters each time the battery is discharged according to the output signal; and selecting the optimal battery parameters from at least two sets of voltage parameters as the target battery parameters. The battery parameters include the maximum voltage, the minimum voltage, and the voltage drop slope of the battery each time it is discharged.

[0117] Furthermore, the screening of the optimal voltage parameters as the target battery parameters from at least two groups of battery parameters includes: selecting a maximum voltage with the largest voltage as the target maximum voltage from the at least two groups of battery parameters; selecting a minimum voltage with the smallest voltage as the target minimum voltage from the at least two groups of battery parameters; and using the target maximum voltage, the target minimum voltage, and the target voltage drop slope corresponding to the target maximum voltage and the target minimum voltage as the optimal battery parameters.

[0118] Step S43: Obtain a battery capacity table, wherein the battery capacity table includes a correspondence between battery parameters and battery reserve capacity.

[0119] In an embodiment of the present invention, the battery capacity table includes several types of battery reserve capacities and several groups of voltage parameters under each of the battery reserve capacities, each group of voltage parameters includes several test voltages and battery parameters obtained by discharging the battery under each test voltage, wherein the several types of battery reserve capacities are spaced apart by a preset capacity, and the several test voltages are spaced apart by a preset voltage.

[0120] The battery capacity table can be pre-built and stored in the battery detection device. As shown in Table 1, it shows a way to experimentally obtain the battery capacity table. The experimental battery is selected at intervals of 10RC, and the test voltage is selected at intervals of 0.1V within the preset voltage range of 12.8V-8.0V. At a test voltage, according to steps S41 and S42, the battery parameters at the test voltage are measured and recorded, and then constant current discharge is performed to make the battery voltage drop to the next test voltage. The above operation is repeated to record the battery parameters at the test voltage to complete the construction of the battery capacity table.

[0121]

[0122] Table 1

[0123] Specifically, pre-constructing a battery capacity table includes: providing a number of experimental batteries of different known battery reserve capacities; fully charging each experimental battery and leaving it to rest for a preset time threshold (e.g., 24 hours); after leaving it to rest for the preset time threshold, controlling each experimental battery to discharge for a preset time at each test voltage within a preset voltage measurement range, and recording the maximum voltage, minimum voltage, and voltage drop slope at the test voltage, where the test voltage = the right endpoint voltage of the preset voltage range - n*preset voltage interval value, or the test voltage = the left endpoint voltage of the preset voltage range + n*preset voltage interval value, where n is the number of discharge measurements; constructing a battery capacity table based on the maximum voltage, minimum voltage, and voltage drop slope of each test voltage under each known battery reserve capacity.

[0124] It should be noted that the method of measuring the battery parameters of the battery to be tested is consistent with the method of measuring the battery parameters of the experimental battery in the battery capacity table.

[0125] For example, in a pre-constructed battery capacity table, the experimental battery performs m1 intermittent discharges at each test voltage, the sending interval of the input signal sent m1 times is equal to p1, the input duration of the input signal sent m1 times is equal to q1, the duration of the m1 intermittent discharge is equal to the preset duration t1, t1 = (m1-1)*p1+m1*q1, and the maximum voltage, minimum voltage and voltage drop slope of the m1 intermittent discharges under the test voltage are recorded. The maximum voltage of the m1 intermittent discharge is the maximum value of the maximum voltage of the m1 intermittent discharges, the minimum voltage of the m1 intermittent discharge is the minimum value of the minimum voltage of the m1 intermittent discharges, and the maximum voltage drop slope of the m1 intermittent discharge is equal to (the maximum voltage of the m1 intermittent discharges - the minimum voltage of the m1 intermittent discharges) / preset duration t1. When measuring the battery reserve capacity of the battery to be tested, the battery is charged. Send m1 input signals to control battery discharge, obtain the output signal of the battery for input signal feedback within the input duration of the input signal, the sending interval of the input signal sent m1 times is equal to p1, the input duration of the input signal sent m1 times is equal to q1, the duration of m1 intermittent discharges is equal to the preset duration t1, t1=(m1-1)*p1+m1*q1, determine the target battery parameters according to the output signal, the target battery parameters are the maximum voltage, minimum voltage and voltage drop slope of m1 intermittent discharges, the maximum voltage of m1 intermittent discharges is the maximum value of the maximum voltage of m1 intermittent discharges, the minimum voltage of m1 intermittent discharges is the minimum value of the minimum voltage of m1 intermittent discharges, and the maximum voltage voltage drop slope of m1 intermittent discharges is equal to (maximum voltage of m1 intermittent discharges - minimum voltage of m1 intermittent discharges) / preset duration t1.

[0126] Step S44: Determine the battery reserve capacity corresponding to the target battery parameter according to the battery capacity table and the target battery parameter.

[0127] Determining the battery reserve capacity corresponding to the target battery parameter according to the battery capacity table and the target battery parameter includes: inputting the target battery parameter into the battery capacity table; searching the battery reserve capacity matching the target voltage drop slope in the battery capacity table, and using the battery reserve capacity as the battery reserve capacity of the storage battery.

[0128] Furthermore, the voltage drop slope of each battery parameter corresponds to a slope matching range, and searching the battery capacity table for a battery reserve capacity that matches the target voltage drop slope, and using the battery reserve capacity as the battery reserve capacity of the storage battery, includes: determining whether the target voltage drop slope falls within the slope matching range of the effective voltage drop slope; if so, using the battery reserve capacity corresponding to the effective voltage drop slope as the battery reserve capacity of the storage battery.

[0129] Among them, the effective pressure drop slope is the pressure drop slope that best matches the target pressure drop slope.

[0130] Assuming that the target voltage drop slope is equal to 0.5V / t, the effective voltage drop slope is equal to 0.51V / t, the slope matching range is 0.51±0.02V / t, and the battery reserve capacity corresponding to the effective voltage drop slope is equal to 150RC, the target voltage drop slope 0.5V / t falls into the slope matching range 0.51±0.02V / t of the effective voltage drop slope 0.51V / t, and the battery reserve capacity 150RC corresponding to the effective voltage drop slope 0.51V / t is used as the battery reserve capacity of the battery, thereby realizing the measurement of the battery reserve capacity of the battery.

[0131] It can be understood that determining the battery reserve capacity corresponding to the target battery parameters according to the battery capacity table and the target battery parameters is not limited to the specific implementation methods disclosed in the embodiments of the present invention. For example, the target voltage difference between the target maximum voltage and the target minimum voltage of the target battery parameters can be used to determine the battery reserve capacity corresponding to the target voltage difference. Searching for a voltage drop slope that matches the target voltage drop slope in the battery capacity table is also not limited to the specific implementation methods disclosed in the embodiments of the present invention. For example, when the target voltage drop slope and a voltage drop slope in the battery capacity table meet a preset matching condition, the battery reserve capacity corresponding to the voltage drop slope is used as the battery reserve capacity of the battery. When the target voltage drop slope and the voltage drop slope in the battery capacity table do not meet the preset matching condition, return to the battery discharge step to obtain a new target battery parameter.

[0132] The embodiment of the present invention provides a method for measuring the battery reserve capacity of a storage battery, by sending an input signal to the storage battery to control the discharge of the storage battery, obtaining an output signal of the storage battery fed back in response to the input signal within the input duration of the input signal, determining a target battery parameter according to the output signal, obtaining a battery capacity table, the battery capacity table including a correspondence between the battery parameter and the battery reserve capacity, and determining the battery reserve capacity corresponding to the target battery parameter according to the battery capacity table and the target battery parameter. Therefore, the embodiment of the present invention obtains the target battery parameter by controlling the storage battery to discharge at least once, and measures the battery reserve capacity of the storage battery according to the target battery parameter and the battery capacity table including the correspondence between the battery parameter and the battery reserve capacity, thereby reducing the measurement time of the battery reserve capacity of the storage battery and improving the measurement efficiency.

[0133] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Under the concept of the present invention, the technical features in the above embodiments or different embodiments may also be combined, the steps may be implemented in any order, and there are many other changes in different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they may still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for measuring the battery reserve capacity of a battery, characterized in that: Applied to a battery testing device, the battery testing device is electrically connected to the battery via a Kelvin connector, and the method comprises: Sending an input signal to the battery at least twice to control the discharge of the battery, and obtaining an output signal fed back by the battery in response to the input signal within an input duration of the input signal; According to the output signal, a set of battery parameters of the battery each time it is discharged is detected, wherein the battery parameters include a maximum voltage, a minimum voltage and a voltage drop slope of the battery each time it is discharged; Selecting an optimal battery parameter from at least two groups of voltage parameters as a target battery parameter; Acquire a battery capacity table, wherein the battery capacity table includes a correspondence between the battery parameters and the battery reserve capacity, and the voltage drop slope of each battery parameter corresponds to a slope matching range; inputting the target battery parameter into the battery capacity table; Determining whether the target voltage drop slope falls within a slope matching range of an effective voltage drop slope, wherein the effective voltage drop slope is a voltage drop slope in the battery capacity table that matches the target voltage drop slope; If the target voltage drop slope falls within the slope matching range of the effective voltage drop slope, the battery reserve capacity corresponding to the effective voltage drop slope is used as the battery reserve capacity of the storage battery.

2. The method according to claim 1, characterized in that The step of sending an input signal to the battery at least twice to control the discharge of the battery comprises: An input signal is sent to the battery at least twice at a preset frequency to control the discharge of the battery.

3. The method according to claim 1, characterized in that The interval between at least two transmissions of the input signal is random.

4. The method according to claim 1, characterized in that: The step of sending an input signal to the battery at least twice to control the discharge of the battery comprises: An input signal is sent to the battery at least twice to control the battery to discharge up to a preset number of times.

5. The method according to claim 1, characterized in that: The input durations of the input signals sent at least twice are the same, or at least one of the input durations of the input signals sent at least twice is different from the other input durations.

6. The method according to claim 5, characterized in that The unit of the input duration is milliseconds (ms).

7. The method according to any one of claims 1 to 6, characterized in that: The input signal is a discharge current of the battery, and the output signal is an open circuit voltage of the battery fed back in response to the discharge current within the input time period.

8. The method according to claim 1, characterized in that The selecting the optimal voltage parameter from at least two groups of battery parameters as the target battery parameter comprises: Selecting a maximum voltage with the largest voltage among the at least two groups of battery parameters as a target maximum voltage; Selecting a minimum voltage with the smallest voltage among the at least two groups of battery parameters as a target minimum voltage; The target maximum voltage, the target minimum voltage, and the target voltage drop slope corresponding to the target maximum voltage and the target minimum voltage are used as optimal battery parameters.

9. The method according to claim 8, characterized in that The battery capacity table includes several types of battery reserve capacities and several groups of voltage parameters under each of the battery reserve capacities, each group of voltage parameters includes several test voltages and battery parameters obtained by discharging the battery under each test voltage, wherein the several types of battery reserve capacities are spaced apart by preset capacities, and the several test voltages are spaced apart by preset voltages.

10. A battery testing device, characterized in that: The battery testing device is electrically connected to the battery through a Kelvin connector, and the battery testing device includes: a discharge circuit, electrically connected to the battery through the Kelvin connector, and used for sending an input signal to the battery to control the discharge of the battery; a voltage sampling circuit, electrically connected to the storage battery through the Kelvin connector, and used for sampling an output signal fed back by the storage battery in response to the input signal within the input duration of the input signal to obtain a sampled voltage; A controller is electrically connected to the discharge circuit and the voltage sampling circuit, respectively, and is used to control the discharge circuit so that the discharge circuit sends an input signal to the battery, determines a target battery parameter according to the sampled voltage, and obtains a battery capacity table, wherein the battery capacity table includes a correspondence between battery parameters and battery reserve capacity, and determines a battery reserve capacity corresponding to the target battery parameter according to the battery capacity table and the target battery parameter.

11. The battery testing device according to claim 10, characterized in that: The input signal is a discharge current of the battery, and the output signal is an open circuit voltage of the battery fed back in response to the discharge current within the input time period.

12. The battery testing device according to claim 11, characterized in that: The discharge circuit comprises: a switch circuit, electrically connected to the controller and electrically connected to the storage battery through the Kelvin connector, and configured to trigger the sending of a discharge current to the storage battery and generate a trigger signal when the controller controls the switch circuit to be in an on state; The first signal processing circuit is electrically connected to the controller and the switch circuit respectively, and is used to perform signal processing on the voltage signal sent by the controller and the trigger signal sent by the switch circuit, and output a driving signal to control the size of the discharge current.

13. The battery testing device according to claim 12, characterized in that: The switch circuit comprises: a first switch, electrically connected to the controller and the first signal processing circuit respectively, and electrically connected to the negative electrode of the battery through the Kelvin connector, and used for controlling the closing or disconnection of the discharge circuit between the controller and the battery according to the control signal sent by the controller, generating a trigger signal, and sending the trigger signal to the first signal processing circuit; The second switch is electrically connected to the first switch and the first signal processing circuit respectively, and is electrically connected to the positive electrode of the battery through the Kelvin connector, and is used to control the magnitude of the discharge current of the discharge circuit according to the drive signal.

14. The battery testing device according to claim 13, characterized in that: The first switch includes a first PMOS tube, a gate of the first PMOS tube is electrically connected to the controller, a source of the first PMOS tube is electrically connected to the negative electrode of the battery through the Kelvin connector, and a drain of the first PMOS tube is electrically connected to the second switch and the first signal processing circuit.

15. The battery testing device according to claim 14, characterized in that: The second switch includes a second PMOS tube, a gate of the second PMOS tube is electrically connected to the first signal processing circuit, a source of the second PMOS tube is electrically connected to the drain of the first PMOS tube and the first signal processing circuit, and a drain of the second PMOS tube is electrically connected to the positive electrode of the battery through the Kelvin connector.

16. The battery testing device according to claim 15, characterized in that: The first signal processing circuit includes a first operational amplifier, a non-inverting input terminal of the first operational amplifier is electrically connected to the controller, an inverting input terminal of the first operational amplifier is electrically connected to the drain of the first PMOS tube and the source of the second PMOS tube, and an output terminal of the first operational amplifier is electrically connected to the gate of the second PMOS tube.

17. The battery testing device according to any one of claims 13 to 16, characterized in that: The discharge circuit further includes a unidirectional conduction circuit, which is electrically connected between the second switch and the positive electrode of the battery and is used to prevent the discharge current from flowing back to the positive electrode of the battery.

18. The battery testing device according to any one of claims 11 to 16, characterized in that: The voltage sampling circuit comprises: a second signal processing circuit, electrically connected to the battery through the Kelvin connector, for performing signal processing on the open circuit voltage of the battery; The voltage divider circuit is electrically connected to the second signal processing circuit and the controller respectively, and is used to divide the output voltage of the second signal processing circuit to obtain a sampling voltage, so that the controller determines the target battery parameter according to the sampling voltage.

19. The battery testing device according to claim 18, characterized in that: The second signal processing circuit includes a second operational amplifier, a non-inverting input terminal of the second operational amplifier is electrically connected to the positive electrode of the battery through the Kelvin connector, an inverting input terminal of the second operational amplifier is electrically connected to the negative electrode of the battery through the Kelvin connector, and an output terminal of the second operational amplifier is electrically connected to the voltage divider circuit.

20. The battery testing device according to claim 19, characterized in that: The voltage divider circuit includes a first resistor and a second resistor; One end of the first resistor is electrically connected to the output end of the second operational amplifier, the other end of the first resistor is electrically connected to the controller and one end of the second resistor; the other end of the second resistor is grounded.

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