The Battery Management System (BMS) is a crucial component of the power battery system in electric vehicles. It detects, collects, and performs preliminary calculations of real-time battery status parameters. It also controls the on/off state of the power supply circuit based on comparisons between detected and permissible values. Furthermore, it feeds back critical data to the vehicle controller and receives instructions from the controller to coordinate with other systems on the vehicle. The requirements for the management system generally differ depending on the type of battery cell.
The lithium-ion batteries used in electric vehicles have large capacities, numerous series and parallel cells, and complex systems. Furthermore, they require high performance in terms of safety, durability, and power, making implementation difficult. Therefore, they have become a bottleneck hindering the widespread adoption of electric vehicles. The safe operating range of lithium-ion batteries is limited by temperature and voltage windows. When these windows are exceeded, battery performance degrades more rapidly and may even lead to safety issues.
The primary purpose of a battery management system (BMS) is to ensure the designed performance of the battery system, providing support in three aspects: safety, durability, and performance. In terms of safety, the BMS protects individual battery cells or the battery pack from damage, preventing accidents. Regarding durability, it extends the battery's lifespan even when operating within a reliable and safe range. In terms of performance, it maintains the battery's operating state to meet vehicle requirements.
A lithium-ion battery pack contains many fast-cell batteries. How does the Battery Management System (BMS) manage them? The important tasks of the BMS system are divided into two main categories: battery detection and ensuring the safety of lithium-ion batteries.
Battery monitoring is relatively simple to implement. The key is to collect parameter information about the battery during use through sensors, such as temperature, voltage and current of each individual battery cell, and voltage and current of the battery pack. This data plays a crucial role in subsequent battery pack management; it can be said that without this battery status data, the system management of power lithium-ion batteries would be impossible.
The key functions of a battery management system can be broken down into the following three aspects:
1. Safety: Protects individual battery cells or battery packs from damage and prevents safety accidents;
2. Durability: Ensures the battery operates within a reliable and safe range, extending its lifespan.
3. Power performance: Maintaining the battery in a state that meets the vehicle's requirements.
