Lithium batteries have revolutionised the automotive industry. electric vehiclesproviding a powerful and efficient power source. However, to maximise their performance and durability, an effective battery management system or BMS is essential.
At NCPOWER, a leader in the development of lithium batteries for electric vehicles, the design and implementation of the BMS is central to our approach to excellence.
When we talk about an electric car battery, we actually mean a collection of many battery cells connected together. These cells are grouped into battery modules, and then these modules are connected to a "battery pack" or what we commonly call "the battery".
This structure in cells, modules and battery packs makes it possible to achieve the capacity and energy necessary for the operation of the electric vehicle. It also facilitates their manufacture, installation, inspection and maintenance. Each manufacturer may have its own design and use different chemical compounds in the battery cells, but in general, they are all lithium batteries, which is the most advanced technology currently available.
Lithium batteries are sensitive to temperature changes, overcharging or excessive discharging. To maximise their service life, it is crucial to carefully monitor and control these conditions. It is also important to avoid temperature leakage, which can occur if the battery is charged or discharged too quickly. To ensure safe and optimal operation, it is necessary to keep the battery within what is known as the "Safe Operating Area".
This involves keeping the battery temperature between -5 and 45 °C, the voltage between 2 and 4 volts, and the current between 0 and 1 ampere. Careful monitoring is essential to ensure that the battery is always within this safe operating area.
Each of these construction steps requires a meticulous quality process to ensure optimal performance and long battery life. At NCPOWER, we pride ourselves on using cutting-edge technologies and following strict manufacturing standards at every step of the process.
Note: Area of safe operation in lithium battery manufacturing at NCPOWER
The BMS and its design
The heart of an efficient and safe battery system lies in the BMS. This system is made up of several essential components, including:
- The battery monitoring integrated circuit (BMIC)
- The Cell Management Controller (CMC)
- The Battery Management Controller (BMC)
The BMIC is responsible for monitoring the individual cells of the battery and must be able to quickly inform the CMC of any unfavourable situations. The speed of communication between the BMIC, the CMC and the BMC is crucial, as it allows an immediate response to correct any problems, such as overheating of a cell. The accuracy of the measurements and the ability to respond to adverse conditions are highly dependent on the frequency of communication between these components.
However, designing an effective communication network in an electric car can be challenging due to the electrical noise present. Reliable and accurate communication between the BMIC, CMC and BMC is necessary to ensure efficient monitoring and control.
In addition to these components, the BMS also includes load balancing circuits to ensure that all cells work in a balanced way and avoid problems. Load balancing is essential to prevent unfavourable situations. The BMS strives to prevent problems from occurring, but if necessary, it will take corrective action.
Depending on the complexity of the electric car, several intelligent microcontrollers can be added to monitor and control specific tasks. It is important that the BMS has the ability to monitor both the battery and its own operation, and to distinguish between real and false alarms.
At NCPOWERWe strive to implement efficient and reliable load balancing strategies, always seeking to achieve the optimal balance between efficiency, cost and reliability.
In the field of BMS, research and development continues to advance steadily. Accurate determination of the state of charge and battery health remains a challenge due to the complexity and variability of the factors involved. At NCPOWER, to address this complexity, we use what we call the Data Center or remote control of NCPOWER batteriesUsing sophisticated computer models and algorithms, we accurately estimate, monitor and predict the optimal cell balancing quantities.
In conclusion, the BMS plays a crucial role in the performance and safety of lithium batteries in electric vehicles. Its ability to monitor charge and discharge, determine the battery's state of charge and health, balance the charge between cells, and record and communicate data is critical for optimal operation.
At NCPOWER, we are proud to lead the way to a more sustainable and efficient future in the electric vehicle industry through our innovative battery and BMS designs.