The key function of a lithium battery BMS is cell balancing. What is a conventional BMS and how is the Flash Balancing System different?
Conferences > 2022 International Conference... This paper explains how the Battery Management System (BMS) in an Electric Vehicle uses cell balancing techniques to balance the li-ion cells in lithium-ion battery pack. Cell balancing is done to ensure that all li-ion cells in a battery pack are charged and drained together.
In those fancy BMS, lithium battery balancing can even be set to occur or not occur depending on the voltage level of the cell groups. In contrast, the most basic, low-cost BMS will always balance the cells regardless of the state of other factors such as cell voltage, discharge or charge state, etc.
There are many reasons the cells in a lithium-ion battery need to be balanced. If a cell group is lower than the others, the BMS will put the battery into safe mode long before the energy in the rest of the cells is used. If a cell group is too high, charging will be cut off before the other cell groups are full.
A BMS (act as the interface between the battery and EV) plays an important role in improving battery performance and ensuring safe and reliable vehicle operation by adding an external balancing circuit to fully utilize the capacity of each cell in the battery pack. The overview of BMS is shown in Fig. 2. Fig. 2. Overview of BMS.
To counteract this phenomenon, a common BMS (battery management system) applies resistance to the cells with a higher charge until the weaker cells catch up to that level. Let’s look at the pros and cons of using this technology: BMS is cost-effective: the simple architecture helps keep the cost of the electronics down.