Battery performance and service life detection device

Abstract

The utility model discloses a battery performance and service life detection device. Comprising a microprocessor, an A / D converter, a control data D / A conversion circuit, a discharge control circuit, a discharge power module, a charge control circuit, a charge power module, a battery pack, a temperature acquisition module, a battery pack battery voltage acquisition module, a battery pack total voltage acquisition module, a charge and discharge current acquisition module and a charge and discharge current acquisition conversion circuit. Voltage, current and temperature of the battery are transmitted to the microprocessor in real time through the acquisition circuit and the AD converter, the microprocessor outputs corresponding data in real time according to an operation instruction and the acquired voltage, current and temperature, the data are converted into analog signals through the D / A conversion circuit, and electric parameters of charging and discharging of the battery are controlled through the charging and discharging control circuit and the power module. Constant-voltage and constant-current charging and discharging are achieved, and the performance, the service life and the like of the battery at different temperatures can be detected.

Description

Technical Field

[0001] The utility model relates to the technical field of battery capacity testing, in particular to a battery performance and life detection device. Background Art

[0002] Battery performance and life detection device is a device used to detect battery performance. Its core function is to comprehensively evaluate the capacity, charge and discharge characteristics and service life of the battery. Battery performance and life detection not only requires the ability to output constant charging current and discharging current to simulate the charging and discharging conditions of the battery in actual use, but also requires multiple functions such as constant voltage control, constant power discharge control and constant resistance discharge control to meet the needs of different battery tests. During the test, the detection device needs to be able to accurately record and analyze the performance parameters of the battery under different conditions, especially under different temperature environments. Because temperature is one of the important factors affecting battery performance parameters, by testing the battery performance at different temperatures, we can have a more comprehensive understanding of the stability and reliability of the battery in actual use and the battery life. Most of the existing battery capacity testers on the market only have battery capacity testing functions, and cannot record the current, voltage and temperature changes of the battery during the entire test process in real time, and calculate the battery capacity, power, etc. For this reason, we propose a battery performance and life detection device. Utility Model Content

[0003] The technical problem to be solved by the utility model is to overcome the existing defects and provide a battery performance and life detection device. The voltage, current and temperature of the battery are transmitted to the microprocessor in real time through the acquisition circuit and the AD converter. The microprocessor outputs the corresponding data in real time according to the operation instructions and the collected voltage, current and temperature, and converts the data into analog signals through the D / A conversion circuit. The electrical parameters of the battery charging and discharging are controlled by the charge and discharge control circuit and the power module to realize constant voltage and constant current charging and discharging. The performance and service life of the battery at different temperatures can be detected, etc., which can effectively solve the problems in the background technology.

[0004] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a battery performance and life detection device, including a microprocessor, an A / D converter, a control data D / A conversion circuit, a discharge control circuit, a discharge power module, a charging control circuit, a charging power module, a battery pack, a temperature acquisition module, a voltage acquisition module for each battery in the battery pack, a total voltage acquisition module for the battery pack, a charge and discharge current acquisition module and a charge and discharge current acquisition conversion circuit, wherein the microprocessor is electrically connected to the A / D converter, the control data D / A conversion circuit, the clock circuit, the charging control circuit and the discharge control circuit respectively, the charging control circuit is electrically connected to the control data D / A conversion circuit and the charging power module respectively, and the discharge control circuit is electrically connected to the A / D converter respectively. The converter is electrically connected to the discharge power module, the battery pack is electrically connected to the temperature acquisition module, the voltage acquisition module of each battery in the battery pack, the total voltage acquisition module of the battery pack, the charge and discharge current acquisition module, the discharge power module and the charging power module respectively, the charge and discharge current acquisition conversion circuit is electrically connected to the temperature acquisition module, the voltage acquisition module of each battery in the battery pack, the total voltage acquisition module of the battery pack and the charge and discharge current acquisition module respectively, the A / D converter is electrically connected to the temperature acquisition module, the voltage acquisition module of each battery in the battery pack, the total voltage acquisition module of the battery pack and the charge and discharge current acquisition conversion circuit respectively; the microprocessor is electrically connected to the process and record data storage unit, and the process and record data storage unit is electrically connected to the data power-off and anti-interference protection circuit.

[0005] As a preferred technical solution of the utility model, the power-off and anti-interference protection circuit maintains a stable voltage of 1.2V at the negative input terminal of the operational amplifier through resistor R6 and the reference voltage regulator when the power supply voltage is between 3-5V. The positive end of the operational amplifier is divided by R5 and R7 to detect the change of the power supply voltage VCC and stop the operation of the clock chip and the data storage chip in advance before the interference signal or power outage, thereby achieving the effect of data protection.

[0006] As a preferred technical solution of the utility model, the power-off and anti-interference protection circuit maintains a stable voltage of 1.2V at the negative input terminal of the operational amplifier through resistor R6 and the reference voltage regulator when the power supply voltage is between 3-5V. The positive end of the operational amplifier is divided by R5 and R7 to detect the change of the power supply voltage VCC and stop the operation of the clock chip and the data storage chip in advance before the interference signal or power outage, thereby achieving the effect of data protection.

[0007] As a preferred technical solution of the utility model, the charging control circuit includes an open-loop comparator 6U1:C, which inputs the constant voltage value required by the battery from the positive terminal of the operational amplifier, and generates a constant voltage control signal to control the constant voltage point of the battery by comparing it with the actual voltage of the battery input at the negative terminal of the operational amplifier; the charging control circuit also includes an open-loop comparator 6U1:D, which inputs the constant current value required by the battery from the positive terminal of the operational amplifier, and controls the constancy of the charging current by comparing it with the charging current value sampled at the negative terminal of the operational amplifier.

[0008] As a preferred technical solution of the utility model, feedback capacitors 6C3 and 6C4 are arranged between the negative input terminals of 6U1:C and 6U1:D and the output terminals of 6U1:C and 6U1:D.

[0009] As a preferred technical solution of the utility model, the discharge control circuit includes an open-loop comparator 7U1:C, which inputs the minimum voltage value that the battery needs to be controlled from the positive terminal of the operational amplifier, and generates a voltage control signal by comparing it with the actual voltage of the battery input at the negative terminal of the operational amplifier, so that the voltage control signal is at a relatively high level; the discharge control circuit also includes an open-loop comparator 7U1:D, which inputs the constant current value required by the battery from the positive terminal of the operational amplifier, and generates a discharge current control signal by comparing it with the discharge current value sampled at the negative terminal of the operational amplifier to control the constancy of the discharge current.

[0010] As a preferred technical solution of the utility model, feedback capacitors 7C3 and 7C4 are arranged between the negative input terminals of 7U1:C and 7U1:D and the output terminals of 7U1:C and 7U1:D.

[0011] As a preferred technical solution of the utility model, the charging control signal in the charging power module adjusts the voltage of the base of 6Q4, is amplified by 6Q5 to drive the subsequent Qc1-Qcn charging power tube group, thereby charging the battery; the discharge control signal in the discharging power module adjusts the voltage of the base of 7Q3, is amplified by 7Q4 to drive the subsequent Qf1-Qfn discharge power tube group, thereby discharging the battery.

[0012] As a preferred technical solution of the utility model, in the charging power module and the discharging power module, the power supply of the front-stage driving circuit is disconnected when the power is off through the relay control power supply VR and VBAT. When there is power, the unidirectional conduction characteristics of 1D5 and 1D6 are used to prevent the reverse connection of the battery from causing current backflow. Each emitter in the power tube group of the charging circuit is connected with an anti-reverse protection diode Dc1-Dcn, and the output of the front-stage driving tube 6Q4 is connected to the next-stage driving with an anti-reverse diode 6D5; each collector in the power tube group of the discharging circuit is connected with an anti-reverse protection diode Df1-Dfn, and the output of the front-stage driving tube 7Q3 is connected to the next-stage driving with an anti-reverse diode 7D4.

[0013] As a preferred technical solution of the utility model, the microprocessor is also electrically connected to the voltage, current, temperature and working status display module. The A / D converter transmits the electrical signals collected by the temperature acquisition module, the battery pack voltage acquisition module for each battery and the battery pack total voltage acquisition module to the microprocessor. The microprocessor obtains the data and displays it on the voltage, current, temperature and working status display module, which can be a commonly used display screen.

[0014] Compared with the prior art, the beneficial effects of the utility model are as follows: the voltage, current and temperature of the battery are transmitted to the microprocessor in real time through the acquisition circuit and the AD converter in the battery performance and life detection device. The microprocessor outputs the corresponding data in real time according to the operation instructions and the collected voltage, current and temperature, and converts them into analog signals through the D / A conversion circuit. The battery is charged and discharged by the charge and discharge control circuit and the power module. The electrical parameters of the battery are controlled to achieve constant voltage and constant current charging and discharging, and the performance and service life of the battery at different temperatures can be detected. And because the battery test cycle is very long, which may be several years, considering the integrity of all test record parameters, an independent power failure protection circuit for stored data is designed to ensure that the data is not lost. After the power failure, even if the person is not on site, the device will automatically start to carry out the subsequent testing work, overcoming the defect that other similar products must be restarted by people. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall framework of the utility model;

[0016] Figure 2 It is a schematic diagram of the power failure and anti-interference protection circuit of the utility model;

[0017] Figure 3 A schematic diagram of a control circuit for battery charge and discharge control and charge and discharge current switching sampling of the utility model;

[0018] Figure 4 It is a schematic diagram of the charging control circuit, the discharging control circuit, and the low-voltage control high-voltage charging and discharging circuit of the utility model;

[0019] Figure 5 It is a schematic diagram of the charging and discharging power module circuit and the battery reverse connection protection circuit of the utility model;

[0020] Figure 6 It is a schematic diagram of the battery voltage detection circuit of the utility model. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0022] See also Figure 1-6 The utility model provides a technical solution: a battery performance and life detection device, including a microprocessor, an A / D converter, a control data D / A conversion circuit, a discharge control circuit, a discharge power module, a charging control circuit, a charging power module, a battery pack, a temperature acquisition module, a battery pack voltage acquisition module for each battery, a battery pack total voltage acquisition module, a charge and discharge current acquisition module and a charge and discharge current acquisition conversion circuit, the microprocessor is respectively electrically connected to the A / D converter, the control data D / A conversion circuit, the clock circuit, the charging control circuit and the discharge control circuit, the charging control circuit is respectively electrically connected to the control data D / A conversion circuit and the charging power module, and the discharge control circuit is respectively electrically connected to the It is electrically connected to the A / D converter and the discharge power module, the battery pack is electrically connected to the temperature acquisition module, the voltage acquisition module of each battery in the battery pack, the total voltage acquisition module of the battery pack, the charge and discharge current acquisition module, the discharge power module and the charging power module respectively, the charge and discharge current acquisition conversion circuit is electrically connected to the temperature acquisition module, the voltage acquisition module of each battery in the battery pack, the total voltage acquisition module of the battery pack and the charge and discharge current acquisition module respectively, the A / D converter is electrically connected to the temperature acquisition module, the voltage acquisition module of each battery in the battery pack and the total voltage acquisition module of the battery pack respectively; the microprocessor is electrically connected to the process and record data storage unit, and the process and record data storage unit is electrically connected to the data power-off and anti-interference protection circuit.

[0023] For more details, please refer to the preferred technical solution Figure 2 Data protection circuits are generally used in the design of many devices. Generally, a backup battery is added to the circuit that needs to be protected. However, this application is to shield the control signal of the circuit that stores data in advance to ensure reliable data protection. The details are as follows:

[0024] The key data in the operation of the instrument is protected against power failure and interference. When the power supply voltage is between 3-5V through R6 and the reference voltage regulator, the negative input terminal of the operational amplifier maintains a stable voltage of 1.2V. The positive terminal of the operational amplifier is divided by R5 and R7 to detect the change of the power supply voltage VCC:

[0025] U14 positive electrode (pin 3) voltage = R7 / (R5+R7)*VCC

[0026] When the power supply voltage VCC is higher than 4.3V, the amplifier (pin 1 of U14) outputs a high voltage, and the data chip select, write, and clock chip select signals are read and written to the data storage chip and the clock chip through the three NAND gates A., B, and D of U10. When the power supply voltage VCC is lower than 4.3V, the amplifier outputs (pin 1 of U14) a low voltage, which controls the three NAND gates A., B, and D of U10 to output a high level, closing the clock chip chip select, data storage chip chip select, and write signals, and stopping the operation of the clock chip and data storage chip in advance before the interference signal or power failure, thereby achieving data protection. In order to prevent data loss in the case of power failure, a backup battery (3.6V rechargeable battery) is added to the circuit design. When there is power, the backup battery is charged through D2, D3, and R9. Through the relationship between D4 and D5, it automatically switches seamlessly when there is power and when there is no power, and adds power to the data storage chip to ensure that data is not lost when there is no power.

[0027] For more details, please refer to the preferred technical solution Figure 3 In the design of battery charging and discharging, charging and discharging are never allowed to occur at the same time, so relays or contactors are generally used to achieve this. Its defects are that it is mechanical, the control action is slow, and the contacts are easily damaged due to instantaneous electric sparks. In addition, when the equipment is powered on or off, if one relay is used for charging and one relay is used for discharging, they will act at the same time, causing charging and discharging to be out of control. If the same relay is used, it will act frequently when powered on and off, causing contact damage. In order to achieve this conversion, we fully use electronic devices and circuits that guarantee uniqueness regardless of the state, and also guarantee instantaneous switching of charging and discharging, which are described below.

[0028] During the battery test, the charging and discharging processes must not allow the charging and discharging circuits to work at the same time, so a reliable control circuit is required to ensure that they do not happen at the same time; the current flows in the two working states of charging and discharging are opposite, so a control signal that controls the current sampling synchronously with the charging and discharging is also required. The high and low levels of the two control signals CTLA and CTLB are controlled by Figure 3 The circuit solves the above two problems reliably.

[0029] Truth Table

[0030]

[0031] In the above table, when CTLC is at a low level, charging is controlled; when CTLF is at a low level, discharging is controlled; when CTDC is at a high level, charging current is sampled; and when CTLF is at a high level, discharging current is sampled. It can be seen from the above circuit diagram and truth table that only when CTLA is at a high level and CTLB is at a low level, the CTLC charging control signal is at a low level through U7:D, U7:E NOT gates and U11:B NAND gates, controlling the collector of 6Q2 to be at a high potential, while the discharge control signal CTLF outputs a high level through U7:D, U7:E NOT gates and U11:C NAND gates, and outputs a low potential through the collector of 7Q2, prohibiting the discharge power module from working. Correspondingly, only when CTLA is low and CTLB is high, the CTLF discharge control signal is low through U7:D, U7:E NOT gate and U11:C NAND gate, controlling the collector of 7Q2 to be high potential, while the charging control signal CTLC outputs high level through U7:D, U7:E NOT gate and U11:B NAND gate, and controls the collector of 6Q2 to output low potential, prohibiting the charging power module from working. Figure 3 It can be seen from the circuit diagram and truth table shown that the discharge current sampling control signal CTDF is high only in the discharge state (CTLA is low level, CTLB is high level), and the discharge current is sampled at this time, thereby achieving the purpose of control and sampling synchronization.

[0032] For more details, please refer to the preferred technical solution Figure 4 The charging control circuit uses the open-loop comparator of 6U1(C) to input the constant voltage value required by the battery from the positive terminal of the op amp, and generates a constant voltage control signal by comparing it with the actual voltage of the battery input at the negative terminal of the op amp to control the constant voltage point of the battery; when the voltage does not reach the set voltage value, the output of 6U1:C is high level, and when the battery voltage rises, the output voltage of 6U1:C will drop, controlling the emitter voltage of 6Q1 to drop. The charging current is controlled to drop through the 6Q1 transistor to keep the voltage constant.

[0033] The constant current value required by the battery is input from the positive terminal of the op amp through the open-loop comparator of 6U1(D). It is compared with the charging current value sampled from the negative terminal of the op amp. When the charging current control value is not reached, 6U1:D outputs a high level, and the charging current quickly reaches the current setting value through the 6D2 diode and the 6Q1 transistor. After reaching the setting value, if there is a difference in the electrical signal values ​​at the positive and negative input terminals of 6U1:D, due to the open-loop amplification of 6U1(D), the output of 6U1:D responds quickly to control the constant charging current.

[0034] The constant voltage control signal and the constant current control signal are cleverly synthesized through the relationship between 6D1 and 6D2. During constant current charging, the constant voltage value is set to the maximum value, so that the output of 6U1:C is always at a high potential. In this way, only the constant current control circuit 6U1:D plays a control role in the charging current, thereby achieving constant current charging of the battery. When a certain constant voltage value is set, when the battery voltage does not reach the set value, the charging current is determined by the constant current control circuit. When the battery voltage reaches the set voltage value, the constant voltage control circuit takes effect. Through the relationship between 6D1 and 6D2, the charging current will be controlled to slowly decrease, thereby achieving the purpose of constant voltage control.

[0035] Optionally, in the circuit, because 6U1:C and 6U1:D are in open-loop amplification, they are prone to self-excitation and loss of control. Therefore, feedback capacitors 6C3 and 6C4 are added between the negative input terminals of 6U1:C and 6U1:D and the output terminals of 6U1:C and 6U1:D to eliminate self-excitation and ensure the stability and reliability of the control circuit.

[0036] For more details, please refer to the preferred technical solution Figure 4 The discharge control circuit uses the open-loop comparator of 7U1:C to input the minimum voltage value that the battery needs to be controlled from the positive terminal of the op amp, and generates a voltage control signal by comparing it with the actual voltage of the battery input at the negative terminal of the op amp, so that the voltage control signal is at a relatively high level to prevent the battery from over-discharging; the open-loop comparator of 7U1:D inputs the constant current value required by the battery from the positive terminal of the op amp, and generates a discharge current control signal by comparing it with the discharge current value sampled at the negative terminal of the op amp. When the discharge current deviates from the actual current, the output level of 7U1:D is quickly adjusted to maintain the discharge current constant; the over-discharge control signal (output of 7U1:C) and the current control signal (output of 7U1:D) are cleverly synthesized through 7D1 and 7D2 in an AND logic manner to control the discharge current and over-discharge voltage of the battery.

[0037] Optionally, in the circuit, because 7U1:C and 7U1:D are in open-loop amplification, they are prone to self-excitation and loss of control. Therefore, feedback capacitors 7C3 and 7C4 are added between the negative input terminals of 7U1:C and 7U1:D and the output terminals of 7U1:C and 7U1:D to eliminate self-excitation and ensure the stability and reliability of the control circuit.

[0038] For more details, please refer to the preferred technical solution Figure 4 It is a technical difficulty to control the high voltage with the low voltage of the triode power device in design. Generally, transformer coupling, optocoupler isolation, and auxiliary circuit are used to drive the base of the triode. This approach has a great instability factor. This design adopts a very unique method. Instead of controlling the base of the triode, it controls the emitter of the triode to achieve the purpose of low voltage controlling high voltage.

[0039] Further preferably, in actual use, the battery or battery voltage may range from 2 volts to more than 100 volts, but the control signal output by the operational amplifier is up to 8 volts (VCC). Therefore, when designing, the base of the 6Q1 and 7Q1 transistors is connected to the power supply. In this way, when the emitter voltage of 6Q1 and 7Q1 changes between 0-8V (VCC), the collector voltage of the transistor can be adjusted to achieve the purpose of controlling the high voltage output from the low voltage.

[0040] For more details, please refer to the preferred technical solution Figure 5 The charging control signal is amplified by 6Q5 to drive the Qc1-Qcn charging power tube group behind to charge the battery by adjusting the voltage of the base of 6Q4. In the figure, the consistency requirement of the charging power tube group is relatively high (the amplification factor is best to be the same), but in fact it is impossible. Therefore, in the design, the current balance control is performed by adding Rc1-Rcn resistors to the base of each power tube and Rp1-Rpn resistors to the emitter, so that the current passing through the power tube group is basically consistent, so as to achieve reliable operation of the charging circuit.

[0041] The discharge control signal adjusts the voltage of the base of 7Q3, and is amplified by 7Q4 to drive the Qf1-Qfn discharge power tube group behind to discharge the battery. In the figure, the consistency requirement of the discharge power tube group is relatively high (the amplification factor is best to be the same), but it is actually impossible. Therefore, in the design, the current balance control is performed by adding Rf1-Rfn resistors to the base of each power tube and Rl1-Rln resistors to the emitter, so that the current passing through the power tube group is basically consistent, so as to achieve reliable operation of the discharge circuit.

[0042] Through the combination of Dc1-Dcn and Df1-Dfn, the charging output and the discharging output are organically combined. When charging, the discharging circuit is controlled not to work, and vice versa, when discharging, the charging circuit is not working, and no relay or contactor switching is required.

[0043] A further preferred technical solution is to utilize the unidirectional conductivity of the diode and connect a diode in series at the places where the charging power source and the battery are connected, so as to protect the charging circuit and the discharging circuit from being damaged when the battery is connected in reverse. Figure 5In the charging and discharging circuit, the power supply of the front-stage driving circuit is disconnected when the power is off through the relay control power supply VRR and VBAT. When there is power, the unidirectional conduction characteristics of 1D5 and 1D6 are used to prevent the reverse connection of the battery from causing the current to flow backward. Each emitter in the power tube group of the charging circuit is connected with a reverse connection protection diode (Dc1-Dcn), and the output of the front-stage driving tube 6Q4 is connected to the next-stage driving with an anti-reverse connection diode (6D5); each collector in the power tube group of the discharging circuit is connected with an anti-reverse connection protection diode (Df1-Dfn), and the output of the front-stage driving tube 7Q3 is connected to the next-stage driving with an anti-reverse connection diode (7D4); the protection effect when the battery is reversed is achieved.

[0044] Furthermore, in order to further achieve reliable protection, a special protection circuit consisting of 6Q3, 6R10 and 6D4 is designed. When the battery is connected reversely, the emitter of the 6Q3 transistor is connected to the negative electrode of the battery through the diode, and the base is equivalent to being connected to the positive electrode of the battery through 6R10. In this way, 6Q3 is in a saturated conduction state, so that the base level of the charging pre-driver tube 6Q4 is only 0.7V, which is the forward voltage drop of 6D4. This reliably ensures that the charging driver tube is in a closed state, and there is no charging current output, which effectively achieves the reverse connection protection of the battery.

[0045] For more details, please refer to the preferred technical solution Figure 6 In the test of the battery pack, it is necessary not only to record the total voltage and current of the battery pack, but also to record the partial voltage of each battery at the same time when recording the total voltage, so as to see the matching characteristics and consistency of the entire battery pack. Therefore, the accuracy of partial voltage detection is particularly important. In general design, the acquisition of the total voltage and the acquisition of the partial voltage are in the same circuit, the same power supply and the same ground wire. In this way, it is impossible to eliminate the common mode voltage between the total voltage and each battery partial voltage, and between each battery partial voltage. In addition, each battery voltage acquisition uses its own independent acquisition circuit, which will also cause errors in the voltage of each battery collected between different circuits, affecting the accuracy of the detection. The present application uses an optical isolation device to isolate the partial voltage of each battery, and only samples one battery at a time, and finally inputs it into the same amplifier for acquisition, and finally inputs it into the A / D converter. The circuit for collecting the partial voltage of each battery is optically isolated from the control circuit and the circuit for the total voltage and current, and does not use the same power supply and ground wire. Since only one battery voltage is collected each time, we use high-speed optocoupler relays and high-speed A / D conversion integrated circuits in the design. In order to reduce the connection lines between the microprocessor and the battery voltage collection circuit, the A / D converter uses a serially controlled A / D conversion integrated circuit, making the circuit practical and reliable. The specific working principle is as follows: Figure 6 .

[0046] The control signal sent by the microprocessor is decoded into six unique output signals by 38 decoder 74HC138, inverted by inverter 74HC04, and input into driver integrated circuit 2003 to drive twelve high-speed optocoupler relays Y214. Each output of integrated circuit 2003 drives two high-speed optocoupler relays, one of which is connected in series to the positive terminal of the battery, and the other is connected in series to the negative terminal of the battery. Because of the uniqueness of the output of 74HC138 38 decoder, it is guaranteed that only a group of high-speed optocoupler relays with the same control terminal are connected for each control signal (corresponding to the two optocoupler relays at the battery terminal), thereby ensuring that only the voltage of one of the batteries is transmitted to the common operational amplifier U11 (OP07). As long as the three input signals (A, B, C) of 74HC138 38 decoder are adjusted in time-sharing manner, the voltage of each battery can be collected in time-sharing manner.

[0047] As can be seen from the figure, the voltage collection of the six batteries uses the same operational amplifier U11, which effectively solves the consistency and accuracy of the collected voltage.

[0048] A detection circuit is used to collect six battery voltages. The A / D converter for collection must be high-speed. Considering that it must be isolated from the microprocessor circuit, this design uses high-speed data control and serial A / D conversion integrated circuit TLC2543CN with fewer input and output lines. By utilizing its high-speed conversion characteristics, it is possible to collect the voltage of each battery once within 300 milliseconds when collecting the voltage of each battery in time-sharing mode. In this way, the effect of collecting voltages at the same time is maintained visually. Since TLC2543CN has fewer input and output lines for controlling the collection of data, it also meets the difficulty of having fewer signal lines to be isolated in the design.

[0049] exist Figure 6 In the circuit, the VDD, VSS and ground of the voltage acquisition circuit are different from the power supply VCC and ground of the microprocessor. The relays for battery time-sharing operation, the control of the A / D conversion circuit, and the data input and output lines all use optical isolation devices, thereby ensuring the independence of the voltage acquisition. At the same time, by controlling the optocoupler relay, only one battery is connected to the integrated operational amplifier at a time, thus eliminating the common-mode voltage caused by connecting all batteries at the same time. The operational amplifier only collects the differential voltage of each battery, ensuring the accuracy of the collected voltage.

[0050] Optionally, the device also has its own operating keyboard, that is, a key operating module electrically connected to the microprocessor. Parameters can be set directly on the device, and battery testing can be performed in places where there is no computer. Because the device has a data storage unit and a reliable data protection circuit, even if it is not connected to a computer, the test data can be temporarily stored in the device. Once connected to the computer, the originally temporarily stored test data can be retrieved from the computer to ensure the integrity of the data.

[0051] The undisclosed parts in the present utility model are all prior art, and their specific structures, materials and working principles are not described in detail. Although the embodiments of the present utility model have been shown and described, it is understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present utility model, and the scope of the present utility model is defined by the attached claims and their equivalents.

Claims

1. A battery performance and life detection device, characterized in that: The invention comprises a microprocessor, an A / D converter, a control data D / A conversion circuit, a discharge control circuit, a discharge power module, a charging control circuit, a charging power module, a battery pack, a temperature acquisition module, a voltage acquisition module for each battery in the battery pack, a total voltage acquisition module for the battery pack, a charge and discharge current acquisition module and a charge and discharge current acquisition conversion circuit. The microprocessor is electrically connected to the A / D converter, the control data D / A conversion circuit, the clock circuit, the charging control circuit and the discharge control circuit respectively. The charging control circuit is electrically connected to the control data D / A conversion circuit and the charging power module respectively. The discharge control circuit is electrically connected to the A / D converter and the discharge power module respectively. The battery components The microprocessor is electrically connected to the process and record data storage unit, and the process and record data storage unit is electrically connected to the data power-off and anti-interference protection circuit.

2. A battery performance and life detection device according to claim 1, characterized in that: When the power supply voltage is between 3-5V, the negative input terminal of the operational amplifier maintains a stable voltage of 1.2V through the resistor R6 and the reference voltage regulator, and the positive terminal of the operational amplifier is divided by R5 and R7.

3. A battery performance and life detection device according to claim 2, characterized in that: A backup battery is provided in the power failure and anti-interference protection circuit, and the backup battery is charged through D2, D3 and R9 when there is power.

4. A battery performance and life detection device according to claim 1, characterized in that: The charging control circuit includes an open-loop comparator 6U1:C, which inputs the constant voltage value required by the battery from the positive terminal of the operational amplifier, and generates a constant voltage control signal to control the constant voltage point of the battery by comparing it with the actual voltage of the battery input at the negative terminal of the operational amplifier; the charging control circuit also includes an open-loop comparator 6U1:D, which inputs the constant current value required by the battery from the positive terminal of the operational amplifier, and generates a charging current control signal to control the constant charging current by comparing it with the charging current value sampled at the negative terminal of the operational amplifier.

5. A battery performance and life detection device according to claim 4, characterized in that: Feedback capacitors 6C3 and 6C4 are provided between the negative input terminals of 6U1:C and 6U1:D and the output terminals of 6U1:C and 6U1:D.

6. A battery performance and life detection device according to claim 5, characterized in that: The discharge control circuit includes an open-loop comparator 7U1:C, which inputs the minimum voltage value required for the battery to be controlled from the positive terminal of the operational amplifier, and generates a voltage control signal by comparing it with the actual voltage of the battery input at the negative terminal of the operational amplifier, so that the voltage control signal is at a relatively high level; the discharge control circuit also includes an open-loop comparator 7U1:D, which inputs the constant current value required by the battery from the positive terminal of the operational amplifier, and generates a discharge current control signal to control the constancy of the discharge current by comparing it with the discharge current value sampled at the negative terminal of the operational amplifier.

7. A battery performance and life detection device according to claim 6, characterized in that: Feedback capacitors 7C3 and 7C4 are provided between the negative input terminals of 7U1:C and 7U1:D and the output terminals of 7U1:C and 7U1:D.

8. A battery performance and life detection device according to claim 7, characterized in that: The charging control signal in the charging power module adjusts the voltage of the base of 6Q4, is amplified by 6Q5 to drive the subsequent Qc1-Qcn charging power tube group to charge the battery; the discharging control signal in the discharging power module adjusts the voltage of the base of 7Q3, is amplified by 7Q4 to drive the subsequent Qf1-Qfn discharging power tube group to discharge the battery.

9. A battery performance and life detection device according to claim 8, characterized in that: In the charging power module and the discharging power module, the power supply of the front-stage driving circuit is disconnected when the power is off through the relay control power supply VRR and VBAT, and is unidirectionally conducted through 1D5 and 1D6 when the power is on. Each emitter in the power tube group of the charging circuit is connected with an anti-reverse protection diode Dc1-Dcn, and the output of the front-stage driving tube 6Q4 is connected to the next-stage driving with an anti-reverse diode 6D5; each collector in the power tube group of the discharging circuit is connected with an anti-reverse protection diode Df1-Dfn, and the output of the front-stage driving tube 7Q3 is connected to the next-stage driving with an anti-reverse diode 7D4.

10. A battery performance and life detection device according to claim 1, characterized in that: The microprocessor is also electrically connected to the voltage, current, temperature and working status display module. The A / D converter transmits the electrical signals collected by the temperature acquisition module, the battery pack voltage acquisition module for each battery, the battery pack total voltage acquisition module and the charge and discharge current acquisition conversion circuit to the microprocessor. The microprocessor obtains the data and displays it on the voltage, current, temperature and working status display module.

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