Security Top of Mind as EV Batteries Go Wireless

Analog Devices’ wireless battery management system certified to recent ISO/SAE standard for automotive cybersecurity.

Analog Devices announced last week that its wireless battery management system (wBMS) for electric vehicles (EVs) has been certified to the ISO/SAE 21434 standard for automotive cybersecurity risk management.

Overview of Analog Devices’ wireless battery management system. (Source: Analog Devices.)

Overview of Analog Devices’ wireless battery management system. (Source: Analog Devices.)

The certification could boost confidence for EV manufacturers interested in a wireless BMS, which Analog Devices first introduced to the industry in 2020 in a partnership with General Motors. In a press release announcing the new certification, Analog Devices stated that transitioning batteries from a wired BMS connection to a wireless one facilitates carmakers to scale their EV fleets into higher volume production, providing modularity, flexibility and scalability to make design and assembly processes more efficient by using connector-free batteries.

However, as with any wireless connection, security concerns are top of mind. The ISO/SAE 21434 certification demonstrates a significant step to address these concerns.

“Improving the security and accuracy of EV batteries removes roadblocks in end-users’ buying considerations and advances OEMs’ decisions to expand their EV offerings,” said Roger Keen, General Manager of Battery Management Systems at Analog Devices, in the company’s press release. “With this certification, [Analog Devices] can provide ongoing transparency and seamless deployment within the EV battery supply chain.”

Why a Wireless BMS?

The lithium-ion battery packs that power EVs require supervision. Each use and recharge diminishes their capability, wearing them out. Irregular voltage can at best make the battery deteriorate faster, and at worst trigger a fire or an explosion. But a properly managed battery pack can be safely charged and discharged thousands of times over its life span. Every cell in the battery pack must be strictly managed to keep it within operable state of charge limits.

That’s where the battery management system comes in. Essentially, the BMS is an electronic brain that monitors and adjusts current, voltage, temperature and state of charge of the battery cells. For much more detail, read our three-part series on battery management systems.

Typically, EV batteries are connected to their management system with physical wires. This allows the BMS to be safely contained within the sealed battery pack, an essentially unhackable position. However, a wired BMS requires wires, which add weight and take up space. The wiring harness and connectors can also be a source of cable failure problems.

A wireless BMS aims to resolve those issues. Going wireless reduces the space and weight of the system—Analog Devices claims that its wBMS could save up to 90 per cent of the wiring and up to 15 per cent of the volume in the battery pack. This reduction would make it possible to increase an EV’s driving range, the golden metric for EV makers.

But if going wireless compromises the security of the vehicle, even increased range is not worth the cost. Leif-Erik Schulte, Senior Vice President at TÜV NORD Mobilität, the assessor for the wBMS ISO/SAE 21434 certification, put it plainly in the press release.

“This system certification is a key element to build trust across the full electrification ecosystem,” Schulte said.