Battery Management System for Electric Vehicles

2024-06-06 16:25:55

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The Battery Management System (BMS)of an electric vehicle is a key component in an electric vehicle used to monitor and manage the performance of the battery system, which helps to balance the battery charge and prevent overcharging and over-discharging, thus ensuring the safe, reliable and efficient operation of the lithium-ion battery while optimizing the overall efficiency and life of the battery.

There are two types of EV BMS, low voltage (LV) and high voltage (HV). Low-voltage battery management systems (LVBMS) are mainly used in two- and three-wheeled electric vehicles with ≤30 VAC and ≤60 VDC. High-voltage battery management systems (HVBMS), on the other hand, are designed to address the battery monitoring needs of four-wheeled electric vehicles (EVs) at ≤600 VAC and ≤900 VDC or ≤1,000 VAC and ≤1,500 VDC, especially during fast charging, and play a critical role in ensuring battery health and safety. By proactively monitoring and evaluating the SOC (state of charge), SOH (state of health), and SOT (state of temperature) of EV batteries, HVBMSs can effectively prevent batteries from thermal runaway and dramatically improve efficiency and performance.

Four Common BMS Topologies for Electric Vehicles
An automotive BMS must have key functions such as voltage, temperature, current, battery state-of-charge monitoring, and lithium-ion battery power balance. According to the architecture, there are four main types of EV BMS commonly used in the market:

Centralized BMS
A single controller manages all battery cells and modules. While this design simplifies management, it can limit the scalability of larger battery systems and has the potential to introduce a single point of failure.

Distributed BMS
Multiple controllers operate across specific modules or battery packs. This scalable design enhances system reliability with built-in redundancy and is effective for larger batteries that require individual monitoring.

Modular BMS
Each unit in the system is independent and capable of autonomous operation. This scalable configuration facilitates flexibility in battery size, allowing designers to easily add or remove some BMS modules as needed.

Hybrid BMS
Combining both centralized and distributed architectures, the Hybrid BMS uses a central controller for overall management and modular local controllers for detailed battery monitoring and control, an architecture that provides comprehensive system management and fine-grained control.

Fast-growing Demand for BMS Chips

The electrification of vehicles is accelerating in major markets around the world. Silicon (Si) and silicon carbide (SiC) devices for on-board chargers, inverters, and DC-DC converters play a key role in the operation of electric vehicles and account for a large percentage of the semiconductor value of the vehicle. High-power electronic components, such as inverters, account for a sizable share of the value of manufacturing electric vehicles. But IDTechEx, in its report "Semiconductors for Autonomous and Electric Vehicles, 2023-2033," takes a deeper look at the individual chip and wafer level, and finds that the BMS is becoming a major contributor to the demand for semiconductor components in today's electric vehicles.

In a battery management system, there are two main types of chips, one is the main controller that makes the big decisions, and the other is the chip responsible for monitoring and balancing the cells in the battery pack (BMB IC). These BMB ICs collect information from the battery pack's sensors and send it to the main controller, which then issues commands to take action, such as turning on a cooler if the cells overheat. Typically, each BMB IC monitors 10-20 cells, and an EV's battery pack often consists of thousands of cells, so the entire battery pack will contain a sizable number of BMB ICs.

For this, IDTechEx points out in its study that battery management systems can now account for about one-third of the silicon requirements in EV power systems. This is also evidenced by Mordor Intelligence's analysis that the EV battery management system market size is expected to grow rapidly from $8.81 billion in 2023 to $37.71 billion in 2028, at an expected CAGR of 33.76% from 2023 to 2028.

Also according to Yole Intelligence's analysis and forecast, the global market for passenger cars and light commercial vehicles will reach 93 million units in 2028, with xEVs having a market share of 53.5%. xEVs are expected to grow at a CAGR of 22.1% from 2022 to 2028. Along with this tremendous growth, EV BMS, including pure EVs and PHEVs, has realized rapid expansion, with the total market for BMS set to increase from $5 billion in 2022 to $11.9 billion in 2028, a CAGR of 15.6%. Growth expectations are not as high as those predicted by Mordor Intelligence, but the same double-digit growth makes this a market to look forward to.

The market for analog front-end (AFE) chips, a critical component of battery management systems (BMS), is projected to grow from $930 million in 2022 to $2.24 billion by 2028. The market for microcontrollers, another essential component of BMS, is expected to increase from $580 million in 2020 to $1.34 billion by 2028. The market for various sensors, including temperature, current, pressure, and acceleration sensors used in BMS, is anticipated to expand from $1.46 billion in 2022 to $3.5 billion by 2028.

Currently, the electric vehicle battery management system market has a large number of players and is dominated by several key companies such as Renesas, NXP, Infineon, Keihin, TE Connectivity, ADI, and others.