Brief introduction to the working principle and protection function of BMS lithium battery protection board

The working principle of the BMS lithium-ion battery protection board: The reason why the lithium-ion battery needs to be protected is determined by its own characteristics. Since the material of the lithium-ion battery itself determines that it cannot be overcharged, over-discharged, over-current, short-circuited, and ultra-high temperature charge and discharge, the lithium-ion battery components will always appear with a delicate protection board and a current fuse. The BMS protection function of lithium-ion battery is usually completed by the protection circuit board and current devices such as PTC. The protection board is composed of electronic circuits, which can accurately monitor the voltage and charge and discharge of the cell at all times in the environment of -40℃ to +85℃ The current of the loop can be switched on and off in time to control the current loop; PTC prevents severe damage to the battery in a high temperature environment. Ordinary lithium ion battery BMS protection board usually includes control IC, MOS switch, resistor, capacitor and auxiliary devices FUSE, PTC, NTC, ID, memory, etc. Among them, the control IC controls the MOS switch to turn on under all normal conditions to make the cell and the external circuit conduct, and when the cell voltage or loop current exceeds the specified value, it immediately controls the MOS switch to turn off to protect the cell’s Safety. BMS lithium-ion battery protection function introduction: lithium-ion battery protection board BMS.jpg1. Battery protection, similar to PCM, overcharge, overdischarge, overtemperature, overcurrent, and short circuit protection. 2. Energy balance, the entire lithium-ion battery pack, because many batteries are connected in series, after working for a certain time, due to the inconsistency of the battery itself, the inconsistency of the working temperature and other reasons, it will finally show a big difference , It has a huge impact on the life of the battery and the use of the system. Energy balance is to make up for the differences between individual battery cells to do some active or passive charge or discharge management to ensure the consistency of the battery and extend the life of the battery. 3. SOC calculation. Due to the development of technology, there are many methods for SOC calculation. If the accuracy is not high, the remaining power can be judged according to the battery voltage. The most important accurate method is the current integration method (also called the Ah method), Qu003d ∫idt, there are internal resistance method, neural network method, Kalman filter method and so on. 4. Communication. Different systems have different requirements for communication interfaces. The mainstream communication interfaces include SPI, I2C, CAN, RS485, etc. Among them, CAN and RS485 are important for automobiles and energy storage systems. ⒌Battery balance: that is, the single lithium ion battery is balanced and charged, so that each battery in the battery pack reaches a balanced and consistent state. Equalization technology is the key technology of a battery energy management system that is currently being researched and developed in the world. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete it.