First, the voltage detection function. It can accurately measure the voltage of each battery cell connection point of the battery protection board. The principle is to sample the voltage signal on the battery protection board through a high-precision voltage acquisition circuit, and then convert the analog voltage signal into a digital signal through an analog-to-digital converter (ADC), and then the microprocessor processes and analyzes these digital signals to obtain an accurate voltage value, judge whether the voltage is within the normal range, and thus detect whether the battery protection board's monitoring function for the battery cell voltage is normal.
Second, the current detection function. It is mainly used to monitor the current size during the battery charging and discharging process. In terms of implementation, using current detection elements such as shunts or Hall sensors, when the current passes through, a corresponding voltage drop or magnetic field change will be generated. These changes are converted into electrical signals by the sensor, and are also processed by the microprocessor after ADC conversion, and then the current value is determined, which can judge the effectiveness of the protection board against abnormal current conditions such as overcurrent and short circuit.
Third, the protection function test. Including detection of overcharge, over-discharge, overcurrent and short-circuit protection. For example, during the overcharge protection test, the tester inputs a gradually increasing voltage to the battery protection board to simulate the charging process. When the voltage reaches the overcharge threshold set by the protection board, observe whether the protection board can cut off the charging circuit in time. By detecting the voltage or current changes of the relevant pins, it is judged whether the protection action is executed. The principles of other protection function tests are similar, so as to evaluate the protection ability of the protection board to the battery under various abnormal conditions.
Fourth, the balancing function test. The tester can detect whether the balancing circuit of the battery protection board is working properly. By providing different voltage or current conditions to the battery protection board, observe whether it can balance the battery cells so that the voltages of each battery cell tend to be consistent. The principle is to monitor the working status of each component in the balancing circuit and the changes of the battery cell voltage during the balancing process.
Fifth, the communication function test. If the battery protection board has a communication interface, such as SMBus, I2C, etc., the tester can communicate with it, send commands and receive feedback information to check whether the communication protocol of the protection board is correct and whether the data transmission is accurate, so as to ensure that it can normally interact with external devices such as the battery management system.
Sixth, internal resistance detection function. Using specific resistance measurement methods, such as AC injection method or DC discharge method, a small AC or DC signal is applied to the battery protection board, and its response is measured to calculate the equivalent internal resistance of the battery protection board and the battery cell, and determine whether the internal resistance meets the requirements, so as to ensure the charging and discharging performance and safety of the battery.
The battery protection board tester comprehensively and accurately detects various performance indicators of the battery protection board through a variety of functions and their corresponding implementation principles, providing strong guarantees for the safe and efficient use of batteries.
