GM figures out how to improve battery monitoring

General Motors' lineup of electric vehicles powered by its latest battery platform will have quicker processing capability than its predecessors because of a wireless battery management system the automaker launched on the GMC Hummer EV pickup.

A major advantage of a wireless system is access to multiple channels and a broad bandwidth, Tim Grewe, GM's director of electrification strategy, told Automotive News.

If the primary path is busy or corrupted, a command can be passed through another channel.

The wireless management system eliminates the need to develop specific communication systems or redesign wiring configurations for each future vehicle developed to use GM's proprietary Ultium batteries, according to the automaker.

"In a traditional wired system where you have one wire going between cell module assemblies and a master controller, like a server, it's one-way communication," Grewe said. "If it gets corrupted or busy, you lose" all the system commands.

But with a wireless system, he explained of the technology, "that one wireless controller can directly communicate with the server, or it can bounce it off of the other modular controllers."

The system can run battery pack health checks in real time and help maintain long-term battery health. It reduces wiring within the batteries by up to 90 percent, GM says, which can make the vehicle lighter and free up space for additional batteries — in addition to extending the vehicle's charging range.

The wireless system, which can be updated over the air, was designed to help GM get EVs to the market faster with a common set of battery components to power a range of vehicles. GM has called the system a pillar of its proprietary Ultium battery platform.

The system will be in every Ultium-powered EV. After launching it on the Hummer pickup, Grewe says engineers further realized the technology's potential.

It gives algorithm designers the ability to more accurately estimate battery health and usable battery energy, he said.

It will also provide benefits for GM's nonautomotive projects, such as its partnership with rail supplier Wabtec Corp., Grewe said. Wabtec's locomotives have many more cell module assemblies than a car. The wireless battery management system eliminates network restrictions.

"All these strategies … are open to you because you don't have those fundamental single-lane data restrictions," Grewe said.

GM is now working on monitoring the battery platforms from a system level in addition to a local level, Grewe said.

"You have no restriction on innovation on how to monitor, diagnose and really tell the capability of the cell because you have so much capability with this monitoring system," Grewe said. Engineers can "take the manufacturing data, plus the fleet data, and then go interrogate an individual car. Those algorithms are being developed."

The teams are experimenting with variables and artificial intelligence algorithms to give customers more accurate battery information, he said.

They can "create a new reality on a more accurate state of charge, or more accurate, usable battery energy under cold conditions," Grewe said. "It's just making it much more robust as we progress."