Stronger together: An intelligent BMS system to optimise pack-level battery performance – 23/12/2020

Electrified powertrains are revolutionising products in the automotive industry and beyond, but they are also bringing a new set of challenges. 

A key example is the limited life of lithium ion batteries, which consume considerable amounts of energy and resources to produce. These can account for 30 to 50 per cent of the total cost of the vehicle, yet they degrade over time and their lifetime is potentially shorter than the rest of the hardware. 

Part of the problem is that batteries are traditionally limited by their weakest cell. As the battery begins to age, the weaker cells are placed under greater stress, which means they degrade quicker. This causes the gap between the strongest and the weakest cells to grow, accelerating the demise of the battery. 

Brill Power was founded in 2016 as a spinout from Oxford University. It was set up to develop intelligent battery management systems (BMS) that could address this challenge. 

“The majority of cells within a battery are still usable when the pack is sent to waste,” comments Stuart Grondel, Strategy and Operations Manager at Brill Power. “While studying how batteries degrade over time, our founding team envisioned a method that would use every cell to its full potential.” 

BrillMS is a master slave system that uses advanced embedded control algorithms to ensure that cells are discharged in proportion to their capacity at all times. It uses cell-level power electronics to swap parallel groups in and out to prevent weaker cells being overly stressed. This automatically balances the cells during charge and discharge, reducing the formation of hot spots and preventing a diverging spread of capacities within the pack. This provides up to 60% increased battery life and 15% greater energy yield. 

Having developed the core technology and produced a proof of concept demonstration, Brill Power needed help to commercialise the system and validate it for the automotive market. That support came from the APC’s Technology Developer Accelerator Programme (TDAP), which provided over £100,000 of grant funding, along with access to business development support and expert advice. 

Support from the programme has helped Brill Power to develop the BMS system to the point where it’s industry ready and poised to start testing with an automotive OEM in the first quarter of 2021. The company has expanded its headcount to 15 and continues to grow. Since taking part in the programme, the company has also been successful in a seed funding application and Grondel believes that participation in TDAP helped with this.  

“The great thing about TDAP is that it doesn’t just cover the development of the fundamental tech, it includes the other issues around that, like strategic management and IP protection,” he comments. “It showed us how to build our company and our processes to a suitable standard to engage with the major players in one of the toughest markets out there.” 

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