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Wireless tech to speed EV R&D

One of the challenges faced by manufacturers looking to expedite the development and production of electric cars lies within the battery management system (BMS).

To ensure the pack provides a good service life and power, the BMS must monitor the cells and use that information to optimise and protect the battery.

However, in a centralised system, the BMS needs to be connected to every cell or groups of cells – entailing lots of heavy, complex wiring.

Cells or groups of cells can alternatively be controlled by individual controllers, reducing complexity but increasing cost. 

GM, in order to circumvent such issues, has developed an almost completely wireless battery management system (wBMS) in conjunction with US technology company Analog Devices. 

GM’s wireless battery management system is expected to drive the company’s Ultium-powered EVs to market faster, as time won’t be needed to develop specific communications systems or redesign complex wiring schemes for each new vehicle. The wBMS helps to ensure the scalability of Ultium batteries across GM’s future lineup, encompassing different brands and vehicle segments. Photo taken in GM’s Battery Electrical Lab on Feb. 25, 2020. This facility now follows GM-mandated guidelines to help protect against the spread of COVID-19, including mandatory use of face masks and social distancing. (Photo by Jeffrey Sauger for General Motors)

Its standalone cell-sensing modules report wirelessly to the battery manager, which can then regulate the cells to deliver the best capacity and lifespan. 

The new system reduces the wiring requirement for batteries by up to 90 per cent, which cuts the size of the pack by up to 15 per cent.

This simplifies design, packaging and construction, making it easier to scale production of both the packs and associated cars. 

Using a wBMS has additional benefits as retired packs can easily be repurposed into secondary applications without requiring complex rewiring.