IDTechEx: EV battery management system (BMS) drives a third of silicon demand in EVs

IDTechEx’s new report “Semiconductors for Autonomous and Electric Vehicles 2023-2033” finds that the coming mass adoption of electric vehicles will drive a 10-year CAGR of 20.9% in semiconductors used for electric powertrains. Along with the rise of more autonomous vehicles, this will drive the overall automotive semiconductor market to a CAGR of 9.4% over the next decade.

Since around 2020, EVs have seen exponential year-on-year growth indicating a transition from an earlier adopter technology to a mainstream one, IDTechEx said. As a result, IDTechEx predicts a 15% CAGR in the battery electric vehicle market over the next decade.

Semiconductor technologies have become engrained in internal combustion engine vehicles. However, managing the flow of electricity to and from the battery in an electric vehicle requires significantly more semiconductor administration in the form of power electronics. Silicon (Si) and silicon carbide (SiC) devices used for onboard chargers, inverters and DC-DC converters play a key role in the operation of electric vehicles and make up a significant proportion of the semiconductor value in the vehicle.

Big power electronics components such as the inverter make up a considerable chunk of the value that goes into building an electric vehicle. However, IDTechEx’s report goes down to the level of individual chips and wafers. From this perspective, the battery management system (BMS) becomes a surprisingly large contributor to silicon demand in electric vehicles.

Within the battery management system, there are two main types of chips: the one master controller and then multiple battery monitoring and balancing integrated circuits (BMB ICs), which look after groups of cells. These BMB ICs collect information from voltmeters, thermometers and other sensors in the pack and send that information to the main controller, which can act accordingly—e.g., turning the cooler on if the battery is too warm.

The BMB ICs typically look after 10-20 cells each; the result is a large number of BMB ICs throughout the pack, which can contain thousands of cells. IDTechEx’s research finds that, although power electronics are such a hefty set of components, the battery management system makes up approximately one-third of the silicon demand used to make electric powertrains.

Semiconductor technologies are rapidly evolving and the BMS is not immune from these trends. Although BMB ICs are capable of monitoring between 10 and 20 cells within the pack, this number is growing. This is likely due to the gradual move to more advanced silicon processes giving more powerful and more capable chips. The effect of this is a reduction in chips required throughout the battery pack. This is compounded by trends towards fewer cells per vehicle, enabled by growing cell capacities.