Commonly used equalization charging technologies in Hefei lithium-ion battery protection panels include constant shunt resistor equalization charging, switched parallel resistor equalization charging, average battery voltage equalization charging, switched capacitor equalization charging, buck converter equalization charging, and inductor equalization charging. When lithium-ion batteries are charged in series, each battery must be charged evenly; otherwise, the overall battery performance and lifespan will be affected during use. However, existing single-chip lithium-ion battery protection chips lack equalization charging control functions, and the equalization charging control function for multi-chip lithium-ion battery protection chips requires an external CPU. Serial communication with the protection chip (such as via I2C bus) increases the complexity and design difficulty of the protection circuit, reduces system efficiency and reliability, and increases power consumption.
According to the application requirements, the lithium-ion battery protection board balance principle can realize the protection and balance of the power lithium-ion battery pack structure and voltage level after changing the protection chip mode, serial number, power switching equipment and energy consumption component circuit.
Lithium-ion batteries, as a type of battery with large energy storage, are widely used in fields such as computer rooms, communication base stations, and data centers. Lithium-ion battery protection boards have the function of protecting the battery and preventing overcharging.
Passive balancing and active balancing of lithium-ion battery protection boards:
The battery itself has usable capacity, but due to imbalances between cells and limitations imposed by the safety voltage settings protecting the battery, the battery system cannot continue to function as intended. Furthermore, the battery life of a car is shorter than the lifespan of the car itself, requiring battery replacement even before the car reaches the end of its lifespan to maintain performance. However, the cost of battery replacement is so high that electric vehicles are significantly limited in this regard.
The primary cause of imbalance is temperature. Generally, when the ambient temperature exceeds the optimal temperature by 10°C, the lifespan of a lithium-ion battery is halved. Because the number of batteries in a vehicle battery system connected in series is very large, typically between 88-100, with a capacity generally between 20-60 kWh, temperature differences arise due to the different mounting positions of each battery. Even within the same battery pack, temperature variations occur due to differences in heating locations and battery configurations. These temperature differences significantly negatively impact battery life, causing imbalance, reducing driving range, and shortening cycle life. Due to these issues, the entire battery system's capacity cannot be fully utilized, leading to battery system degradation. Reducing system degradation will greatly extend the battery system's lifespan.
