Principle of BMS lithium-ion battery protection board -Lithium - Ion Battery Equipment
The working principle and selection method of BMS lithium-ion battery protection board. The BMS lithium-ion battery protection board is very important in the battery protection system. The lithium-ion battery protection board will be used in the planning process of the lithium-ion battery pack. It may be the corresponding BMS to better plan the lithium-ion battery pack, or even help The quality section analyzes abnormal cells or circuits together. This article introduces the principle and purchasing skills of lithium-ion battery protection board BMS.(Lithium - Ion Battery Equipment)
Lithium-ion battery important parts:
Lithium-ion battery consists of two important modules, battery cell and protection board PCM (power lithium battery is often referred to as battery processing system BMS). The battery is the heart of the lithium-ion battery, and the processing system is the brain of the lithium-ion battery. The core is mainly composed of positive electrode material, negative electrode material, electrolyte, barrier and shell, and the protection board is mainly composed of protection chip (or processing chip), MOS tube, resistor, capacitor and PCB board.
What is BMS?
BMS is actually a lithium-ion battery processing system, which means, a module dedicated to the operation and processing of lithium-ion batteries, and its object is lithium-ion batteries. The important object is the secondary battery. The important thing is to improve the utilization rate of the battery and prevent the battery from being overcharged and overdischarged. It can be used in electric vehicles, battery cars, robots, drones, etc. In addition, BMS remains the common storage format for computer music and game files, and is the name of the next generation of telecommunications service processing systems.
The working principle of BMS lithium-ion battery protection board:
Lithium-ion batteries need to be protected due to their own characteristics. Since the lithium-ion battery itself is made of materials that prevent it from being charged and discharged, overcharged, short-circuited, and charged and discharged at ultra-high temperatures, the lithium-ion battery assembly always has a well-designed protection plate and a current fuse.
The BMS protection function of the lithium-ion battery is generally completed by the protection circuit board, PTC and other current devices. The protection board is composed of electronic circuits, which can accurately monitor the voltage of the battery and the current of the charging and discharging circuit in the environment of -40~+85, and control the on-off of the current circuit in time. PTC prevents serious damage to the battery at high temperatures.
General lithium-ion battery BMS protection boards generally include control ICs, MOS switches, resistors, capacitors and fuses, PTC, NTC, ID, memory, etc. At the same time, the IC is controlled to control the conduction of the MOS switch under normal conditions, so that the battery is conducted with the external circuit. When the battery voltage or circuit current exceeds the specified value, it immediately controls the disconnection of the MOS switch to protect the safety of the battery.
BMS lithium-ion battery protection function:
2. The energy balance of lithium-ion battery packs, because many batteries are connected in series, after the operation is pressed for time, due to the contradiction of the cells themselves, and to a certain extent due to the inconsistent working temperature, it will show a big difference in the end. Huge impact on energy balance is to bridge the differences between individual batteries by doing some active or passive charging or discharging process, ensuring battery consistency and extending battery life.
3. SOC accounting: Due to the development of technology, many methods of SOC accounting have been accumulated. For those with low accuracy requirements, the remaining power can be judged according to the battery voltage.
4. Communication: Different systems have different requirements for communication interfaces, such as SPI, I2C, CAN, RS485, etc. In automotive and energy storage systems, the first is CAN and RS485.
Balancing between cells: Balance charging a single Li-Ion cell to bring all cells in the pack to a consistent state of balance. Equalization technology is a key technology of a battery energy processing system that is currently being researched and developed internationally.