Battery Management Systems

The battery management system or BMS is an integral part of any lithium-ion battery pack. Compared to lead acid and nickel metal hydride (NiMH) cells, lithium cells can be much more temperamental. Discharging a lithium cell too far can accelerate aging, as does overcharging. High temperatures and overcharging can also lead to the cell failing and causing fires. The BMS is in place to control these parameters and keep the battery pack safe. It monitors voltages, temperatures, and currents and can limit charge or discharge accordingly, as well as influencing the thermal management system to keep the pack in an optimal temperature window. This premium article covers the basic architecture of battery management systems, highlights key components, presents example products from leading suppliers, discusses innovation in the BMS, and gives an overview of the supply chain. This is all done with a focus on the underlying semiconductor technologies supporting BMSs.