A portable lead-acid and lithium battery rapid detection device

Abstract

The utility model relates to a portable lead acid and lithium battery quick detection device belongs to the battery test equipment technical field, the device, including man -machine interaction host computer and data acquisition box, man -machine interaction host computer and data acquisition box between through the mode of 485 communication carry out data interaction. Data acquisition box contains main control module, signal generation module, measurement module. Each module realizes function integration through hardware circuit connection. Main control module is responsible for system control and data processing, and signal generation module provides the excitation signal required for testing, and measurement module realizes high-precision collection of battery electric parameters, and man -machine interaction host computer provides information display and data interaction function and load discharge control. The device can integrate quick discharge test, AC / DC resistance measurement and electrochemical impedance spectroscopy analysis function, each module adopts independent PCB design, and the overall volume is small, and the weight is light, and is suitable for on -the -spot quick detection, solves the problem that the existing equipment is single function, low integration, poor portability and big measurement interference.

Description

Technical Field

[0001] This utility model belongs to the technical field of battery testing equipment, specifically relating to a portable rapid testing device for lead-acid and lithium batteries. Background Technology

[0002] As a core component of energy storage and supply, the performance testing of batteries is crucial in fields such as communication base stations, new energy vehicles, and energy storage systems. Existing portable battery testing equipment has several shortcomings: some devices (such as the portable battery testing system disclosed in patent CN202320075284.5) focus on improving energy conversion efficiency, only providing basic charge / discharge conditions and voltage / current acquisition functions, failing to achieve in-depth testing of battery internal resistance and electrochemical characteristics. High-precision electrochemical impedance spectroscopy (EIS) analysis equipment is mostly laboratory-specific, bulky, costly, and requires fixed locations, failing to meet on-site testing needs. Traditional capacity testing equipment requires completing a full charge / discharge cycle, taking several hours and resulting in low testing efficiency. Furthermore, existing equipment struggles to integrate high-power discharge testing with low-amplitude EIS signal measurement, as signal interference easily occurs, leading to decreased measurement accuracy. In summary, there is an urgent need for a highly integrated, portable, efficient, and high-precision on-site battery testing device. Utility Model Content

[0003] The purpose of this invention is to provide a portable rapid testing device for lead-acid and lithium batteries. Through optimized design and integration of hardware modules, it solves the problems of existing equipment having limited functionality, poor portability, low testing efficiency, and significant measurement interference.

[0004] To achieve the above objectives, the technical solution of this utility model is: a portable rapid testing device for lead-acid and lithium batteries, comprising a data acquisition box and a human-machine interface host for data interaction. The data acquisition box integrates a main control module, a signal generation module connected to the main control module for providing the excitation signals required for testing, and a measurement module for acquiring battery electrical parameters. The voltage, current, and resistance data acquisition modules and the data analysis main control module are independent modular units.

[0005] Furthermore, the modules in the device are connected by hardware circuits to work together to complete functions such as rapid discharge testing, AC / DC internal resistance measurement, and electrochemical impedance spectroscopy analysis.

[0006] Furthermore, the main control module is based on the STM32F401 microcontroller and integrates data processing circuits, storage interface circuits, and communication interface circuits in hardware.

[0007] Furthermore, the signal generation module is based on the STM32F071 microcontroller and includes a DAC signal generation circuit for measuring AC internal resistance and electrochemical impedance spectroscopy; the DAC signal generation circuit can generate a sinusoidal AC excitation signal with a frequency of 1Hz to 20kHz and an amplitude of 10mV RMS.

[0008] Furthermore, the measurement module includes an EIS measurement path and a high-speed acquisition path for synchronously acquiring amplified voltage and current signals. The EIS measurement path includes a Howland constant current source circuit for converting the AC excitation voltage signal into a 20mA AC constant current signal for injection into the battery and a differential amplifier circuit for amplifying the microvolt-level response voltage across the battery. The Howland constant current source circuit uses a precision operational amplifier NCV20074 and a 4.7Ω±0.1% precision reference resistor. The differential amplifier circuit uses an amplifier with a high common-mode rejection ratio, INA828. The high-speed acquisition path uses a high-speed ADC built into the STM32F401 main control module.

[0009] Furthermore, the human-machine interface host includes a control system based on a microcontroller STM32F103, a 10-inch serial port display screen connected to the control system for displaying voltage, current, internal resistance, discharge curves, and EIS spectra, a PWM drive circuit connected to the control system for driving electronic loads to perform constant power discharge tests, a USB interface connected to the control system for exporting test data and upgrading device firmware, and a built-in SD card storage interface connected to the control system for connecting an SD card to store test data and historical records; the 10-inch serial port display screen is connected to the control system via a communication circuit.

[0010] Furthermore, the human-computer interaction host also includes a high-power electronic load, and the PWM drive circuit is connected to the control circuit of the high-power electronic load.

[0011] Furthermore, the control circuit of the high-power electronic load is equipped with a discharge circuit open-circuit protection circuit and a zero-current shutdown circuit.

[0012] Furthermore, each module adopts an independent PCB design, with standardized input / output interfaces reserved on the PCB board. The modules are connected through interface plug-ins to form a complete hardware system.

[0013] Furthermore, a time-sharing measurement control circuit connected to the main control system is also provided, which can periodically pause the operation of the high-power electronic load during the discharge test.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] 1. High functional integration: Through hardware module integration, one device can simultaneously realize rapid discharge testing (2000W constant power), AC / DC internal resistance measurement, and EIS analysis functions without the need for multiple additional devices, meeting comprehensive on-site testing needs and reducing equipment procurement and carrying costs.

[0016] 2. High testing efficiency: Constant power discharge test can be completed in 15 minutes. With EIS measurement every 3-5 seconds, key battery performance tests can be completed within 20 minutes. Compared with traditional full charge and discharge test (several hours), the efficiency is improved by more than 10 times.

[0017] 3. High measurement accuracy: The Howland constant current source circuit and INA828 differential amplifier circuit work together to ensure that the EIS measurement amplitude error is <±3% and the phase error is <±5%; the time-division measurement hardware control design effectively isolates discharge interference, further improving the measurement accuracy.

[0018] 4. High portability: The modular PCB design and compact shell structure keep the overall size of the device within 500mm×400mm×300mm and the weight ≤12kg, making it easy to carry on site.

[0019] 5. High reliability: Hardware protection designs such as electronic load open circuit protection and zero current shutdown, as well as a stable power supply module, can effectively avoid damage to the device or battery under abnormal operating conditions (such as open circuit or overvoltage), and extend the service life of the equipment. Attached Figure Description

[0020] Appendix Figure 1 The overall hardware architecture diagram of the device shows the connection relationship between the data acquisition box, the human-computer interaction host, and the battery;

[0021] Appendix Figure 2 The main control module PCB schematic shows the circuit connections between the STM32F401 and the storage and communication interfaces.

[0022] Appendix Figure 3 : Schematic diagram of Howland constant current source circuit, showing the connection method of NCV20074 op-amp and precision resistor;

[0023] Appendix Figure 4 Schematic diagram of a high-power electronic load control circuit, including MOSFETs, sampling resistors, and protection circuits;

[0024] Appendix Figure 5 High-precision, low-noise differential amplifier circuit;

[0025] Appendix Figure 6 Screenshot of the data analysis main control module;

[0026] Appendix Figure 7 Physical image of the data analysis main control module;

[0027] Appendix Figure 8 Physical image of the data acquisition module. Detailed Implementation

[0028] The technical solution of this utility model will be described in detail below with reference to the accompanying drawings.

[0029] This invention provides a portable rapid testing device for lead-acid and lithium batteries, including a data acquisition box and a human-machine interface host for data interaction. The data acquisition box integrates a main control module, a signal generation module connected to the main control module for providing the excitation signals required for testing, and a measurement module for acquiring battery electrical parameters. The human-machine interface host provides information display, data interaction functions, and load drive control.

[0030] The following are specific implementation examples of the device of this utility model.

[0031] like Figure 1-5 As shown, a portable rapid testing device for lead-acid and lithium batteries includes:

[0032] 1. Data acquisition box:

[0033] Main control module: The core chip uses an STM32F401 microcontroller, and the hardware circuit includes:

[0034] Data processing circuit: integrates operational amplifiers and logic control chips to perform preliminary filtering and logic conversion on the acquired voltage and current signals, providing stable input for microcontroller data processing;

[0035] Storage interface circuit: An SPI interface chip is set up to realize real-time storage of test data;

[0036] Communication interface circuit: Includes UART and USB communication chips, which are used to communicate with the display screen and external devices (such as computers) to realize the display of test results and data export.

[0037] Signal generation module: The core chip uses an STM32F071 microcontroller, and the hardware circuit includes:

[0038] DAC signal generation circuit: It consists of the built-in DAC module of STM32F071 and an external operational amplifier (model NCV20074), which can output a sinusoidal AC signal with a frequency of 1Hz to 20kHz and an amplitude of 10mV RMS, as the excitation source for EIS measurement and AC internal resistance measurement.

[0039] Measurement module: Includes EIS measurement path and high-speed acquisition path.

[0040] EIS measurement pathway:

[0041] Howland constant current source circuit: Composed of precision operational amplifier NCV20074 and 4.7Ω±0.1% precision reference resistor (RCAL), it can convert the AC voltage signal generated by DAC into a stable 20mA AC constant current signal and inject it into the battery under test;

[0042] Differential amplifier circuit: The INA828 high-precision amplifier is used, with a common-mode rejection ratio of >100dB, which can effectively suppress common-mode interference and amplify the microvolt response voltage generated at both ends of the battery to the range that the ADC can collect (0-3.3V).

[0043] High-speed acquisition path: Utilizing the STM32F401's built-in 12-bit high-speed ADC, with a sampling rate set to 100kS / s, the amplified voltage and current signals are acquired synchronously (converted through the voltage across the sampling resistor) to ensure complete acquisition of high-frequency signals (20kHz).

[0044] 2. Human-Computer Interaction Host:

[0045] Control system: The core chip uses an STM32F103 microcontroller.

[0046] Display interface circuit: It adopts a UART communication chip to connect to a 10-inch serial port display (1024×600 resolution) to display test parameters (voltage, current, internal resistance) and test curves (discharge curve, EIS Nyquist plot).

[0047] SD card interface circuit: adopts SPI communication protocol, sets up card slot and level conversion chip, supports SD card up to 32GB, and realizes test data storage by timestamp;

[0048] USB interface circuit: Supports data transfer rate of 12Mbps, used to export test data from SD card to computer.

[0049] PWM drive circuit: A MOSFET driver chip (model IR2104) is used to amplify the PWM signal output by the STM32F071 to drive high-power electronic loads;

[0050] High-power electronic load control circuit: The IRFP260NPBF power MOSFET is used as the core switching element, and a constant power control loop is formed with a sampling resistor (500mΩ) to realize constant power discharge test.

[0051] This utility model device also features the following key hardware optimization designs.

[0052] (1) Time-sharing measurement anti-interference design: A logic control circuit is set between the main control module and the load control module. The time-sharing control of "discharge-resting-EIS measurement" can be realized through hardware trigger signal: During the discharge test, the logic circuit triggers the electronic load to work and the EIS measurement path is disconnected; every 2 minutes, the logic circuit cuts off the electronic load drive signal and triggers a 3-second resting wait (implemented by timer chip). After the resting is completed, the EIS measurement path is turned on to complete the 3-5 second EIS signal acquisition, effectively avoiding the interference of large discharge current on the EIS small amplitude signal.

[0053] (2) Electronic load protection design: In the high-power electronic load control circuit, the following settings are made:

[0054] Open circuit protection circuit: A voltage comparator (model LM339) is used to monitor the discharge circuit voltage. When the circuit is open and the voltage exceeds the threshold (50V), a protection signal is immediately output to cut off the MOSFET drive and stop the discharge.

[0055] Zero-current shutdown circuit: The circuit current is monitored by a current sampling resistor. When the constant current is set to 0, the MOSFET is triggered to turn off completely, preventing weak leakage current from affecting the battery or measurement accuracy.

[0056] In the assembly structure of this utility model, each module adopts an independent PCB design with uniform PCB board size and a 2.54mm spacing for the pin socket interface on the board edge. The outer shell of the device is made of ABS engineering plastic, and a metal partition and fixing bracket are set inside. The PCB boards of each module are fixed by the bracket, and the modules are connected to the pin socket interface by ribbon cables to form a modular assembly structure, which facilitates debugging, maintenance and subsequent module upgrades.

[0057] Figure 6 This is a schematic diagram of the outer shell and internal assembly structure of the device of this utility model; Figure 7 This is a physical image of the main control module for data analysis of the device of this utility model; Figure 8 This is a physical image of the data acquisition module of the present invention.

[0058] The hardware assembly steps of this utility model device are as follows:

[0059] 1. Solder components according to the PCB schematic of each module: Complete the soldering of the main control module of the data acquisition box (STM32F401, storage interface chip, communication chip), the signal generation module of the data acquisition box (STM32F071, DAC peripheral circuit), the measurement module of the data acquisition box (NCV20074, INA828, ADC sampling circuit), the load control module of the human-machine interaction host (PWM driver chip, power MOSFET), and the human-machine interaction host interface (STM32F103, display interface, SD card interface, USB chip), ensuring that there are no cold solder joints or missing solder joints.

[0060] 2. Module Fixing and Connection: Fix each module PCB board to the metal bracket inside the device housing with screws, and connect each module interface with ribbon cables according to the hardware architecture diagram: The main control module is connected to the signal generation module (UART interface), measurement module (ADC input interface), human-machine interface host (UART, SPI, USB interface), and load control module (UART interface); the signal generation and load control modules are connected to the measurement module (DAC output interface) and high-power electronic load (PWM drive interface).

[0061] 3. External Interface Installation: A display window, USB interface hole, and power interface hole are opened on the device casing. A 10-inch serial display screen, USB interface, and AC power interface are installed respectively, and connected to the corresponding internal modules through ribbon cables.

[0062] Usage process of this utility model device

[0063] 1. Device connection: Connect the battery to be tested to the battery test interface of the device using the alligator clip cable.

[0064] 2. Test Start-up: Turn on the device power switch. The display screen shows the main test interface. Select the "Quick Detection" mode through touch operation. The device will automatically start the test process.

[0065] 3. Automated testing:

[0066] Step 1 (AC internal resistance measurement): The signal generation module outputs a 1kHz AC excitation signal, the measurement module acquires the battery response signal, and the main control module calculates and displays the AC internal resistance.

[0067] Step 2 (Constant Power Discharge): The load control module drives the electronic load to discharge at a set power (default 1000W). The main control module collects voltage and current data every second, plots the discharge curve, and stores it to the SD card in real time.

[0068] Step 3 (Time-division EIS measurement): Every 2 minutes, the device automatically pauses the discharge, and after 3 seconds of rest, it starts the EIS measurement (sweep frequency range 1Hz-20kHz). The measurement data is plotted and stored in real time.

[0069] Step 4 (Test End): After discharging for 15 minutes, the device automatically stops discharging, and the display shows the final test results (AC internal resistance, discharge capacity, EIS spectrum). The data is automatically saved to the SD card.

[0070] 4. Data Export: After the test, the test data file (CSV format) on the SD card can be read from the computer via USB for subsequent analysis.

[0071] Debugging and maintenance of this utility model device

[0072] 1. Module debugging: Each module has an independent PCB design that supports individual debugging. If a certain function is abnormal (such as no data in EIS measurement), the corresponding module (such as the measurement module) can be disassembled separately, and key signals (such as DAC output and amplifier output) can be detected by oscilloscope to locate and replace the faulty component.

[0073] 2. Firmware upgrade: If the device control logic needs to be optimized, the device can be connected to a computer via USB interface, and the firmware upgrade program can be run to write the new firmware to the microcontrollers of the main control module and the signal generation module without disassembling the hardware.

[0074] The above are preferred embodiments of this utility model. Any changes made to the technical solution of this utility model that do not exceed the scope of the technical solution of this utility model shall be protected within the scope of this utility model.

Claims

1. A portable rapid testing device for lead-acid and lithium batteries, characterized in that, It includes a data acquisition box and a human-machine interface host for data interaction. The data acquisition box integrates a main control module, a signal generation module connected to the main control module for providing the excitation signals required for testing, and a measurement module for acquiring battery electrical parameters.

2. The portable rapid testing device for lead-acid and lithium batteries according to claim 1, characterized in that, The various modules in the device are connected by hardware circuits to work together to complete functions such as rapid discharge testing, AC / DC internal resistance measurement, and electrochemical impedance spectroscopy analysis.

3. The portable rapid testing device for lead-acid and lithium batteries according to claim 1, characterized in that, The main control module is based on the STM32F401 microcontroller and integrates data processing circuits, storage interface circuits and communication interface circuits in hardware.

4. The portable rapid testing device for lead-acid and lithium batteries according to claim 1, characterized in that, The signal generation module is based on the STM32F071 microcontroller and includes a DAC signal generation circuit for measuring AC internal resistance and electrochemical impedance spectroscopy. The DAC signal generation circuit can generate a sinusoidal AC excitation signal with a frequency of 1Hz to 20kHz and an amplitude of 10mV RMS.

5. The portable rapid testing device for lead-acid and lithium batteries according to claim 1, characterized in that, The measurement module includes an EIS measurement path and a high-speed acquisition path for synchronously acquiring amplified voltage and current signals. The EIS measurement path includes a Howland constant current source circuit for converting the AC excitation voltage signal into a 20mA AC constant current signal for injection into the battery and a differential amplifier circuit for amplifying the microvolt-level response voltage across the battery. The Howland constant current source circuit uses a precision operational amplifier NCV20074 and a 4.7Ω±0.1% precision reference resistor. The differential amplifier circuit uses an amplifier with a high common-mode rejection ratio, INA828. The high-speed acquisition path uses the high-speed ADC built into the STM32F401 main control module.

6. The portable rapid testing device for lead-acid and lithium batteries according to claim 1, characterized in that, The human-machine interface host includes a control system based on an STM32F103 microcontroller, a 10-inch serial port display screen connected to the control system for displaying voltage, current, internal resistance, discharge curves, and EIS spectra, a PWM drive circuit connected to the control system for driving electronic loads to perform constant power discharge tests, a USB interface connected to the control system for exporting test data and upgrading device firmware, and a built-in SD card storage interface connected to the control system for connecting an SD card to store test data and historical records; the 10-inch serial port display screen is connected to the control system via a communication circuit.

7. A portable rapid testing device for lead-acid and lithium batteries according to claim 6, characterized in that, The human-computer interaction host also includes a high-power electronic load, and the PWM drive circuit is connected to the control circuit of the high-power electronic load.

8. A portable rapid testing device for lead-acid and lithium batteries according to claim 7, characterized in that, The control circuit of the high-power electronic load is equipped with a discharge circuit open-circuit protection circuit and a zero-current shutdown circuit.

9. A portable rapid testing device for lead-acid and lithium batteries according to claim 1, characterized in that, Each module adopts an independent PCB design, with standardized input / output interfaces reserved on the PCB. The modules are connected through interface plug-ins to form a complete hardware system.

10. A portable rapid testing device for lead-acid and lithium batteries according to claim 7, characterized in that, It also features a time-sharing measurement control circuit that is connected to the main control system and can periodically pause the operation of the high-power electronic load during the discharge test.

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