The ever increasing climate deterioration is resulting in accelerated development and adoption of electric vehicles. Especially, the electric 3-wheelers are successfully combating the climate crisis and fast replacing ICE vehicles for last-mile transportation. It is a well-known fact that the battery is the most expensive and important component of an electric cargo vehicle. To ensure a longer service life and safety of the battery, the EV 3-wheeler needs an efficient and effective Battery Management System (BMS).
What is the battery management system (BMS) in electric vehicles?
A Battery Management System (BMS) is an embedded system in an EV that manages a battery, so that the operations of the battery are smooth, safe and efficient. The key constituents of the BMS are the battery pack, control unit, and display unit.
Why is the BMS a crucial component of an EV?
Each cell in a battery pack has its own voltage, current, and temperature features. These need to be constantly managed and monitored to keep them working within their safe operating limits. This management by the BMS ensures the safe, efficient, and longer life of the battery pack.
Here are a few of the functions performed by the BMS:
- Manages and monitors the charging and discharging of the batteries: Charging and discharging are the most risky activities of the battery. BMS enforces the limits of charge or discharge current according to temperature thereby, ensuring that the electric cargo vehicles are operating in safe conditions all the time.
- Indicates the state of charge (SoC): The state of charge of the battery indicates the amount of charge in the battery that determines the range of the electric cargo vehicle. Overcharging as well as deep discharging can harm the battery and reduce its efficiency and life. BMS estimates the amount of current that can safely go in.
- Determines the state of health (SoH): The BMS shows the current capacity of the battery in ratio to the original capacity. Battery health which is 100% when new, deteriorates with charging cycles. Accurate SoH helps in determining the SoC as closely as possible.
- Facilitates cell balancing: Cell balancing is imperative in maintaining the cells at equal voltage levels and optimizing the capacity utilization. The same level of charge and discharge of each cell is important to prevent overloading and destruction of the cells. The BMS applies active or passive techniques to balance the cells so that they are not overloaded, thereby preventing damage to the battery pack.
- Manages Thermal temperatures: The BMS continuously monitors and manages the temperature of the battery. An increase in temperature can reduce the output power. To avoid overheating the BMS measures the average temperature, coolant input and output temperatures, and the temperatures of individual cells. Despite this if the battery does get overheated, the BMS triggers several cooling mechanisms to bring down the battery temperature.
- Communicates internally and externally: BMS can effectively communicate with the internal and external hardware to ensure smooth functioning of the electric three wheeler cargo.
The BMS undertakes continuous monitoring of the state of health of the battery and plays a crucial role in improving battery performance and optimizing vehicle operations in a safe and reliable manner. An efficient BMS is a vital component that can increase battery life, and prevent performance degradation.