Palmer Energy Technology Limited (PETL), a U.K.-based maker of Battery Energy Storage Systems, announced the acquisition of Brill Power, an Oxford University spin‑out focusing on cell‑level control and active balancing technology in battery management systems.
The acquisition will enable PETL to embed Brill Power electronics across its systems with immediate effect, bringing together PETL’s battery storage systems and Brill Power’s control platform, which claims to improve battery safety and extend service life by drawing the optimum current from each cell based on its state of health.
Alongside the acquisition, the company also secured a £5 million (~$6.8 million) Series A funding round, co-led by FirstGroup Energy Limited, the dedicated energy investment arm of FirstGroup, a U.K.-based public transport operator and PETL customer, with additional participation from Barclays Climate Ventures and the University of Oxford.
“This investment continues our strategy of backing new and innovative companies aimed at supporting our long-term public commitment of achieving a zero-emission fleet by 2035. PETL, along with its acquisition of Brill Power, will unlock innovative energy procurement solutions whilst providing second-life use cases when batteries are taken off electric buses,” said Faizan Muhammad, Investment Director at FirstGroup.
The Brill Power brand will continue to be used for module sales to third parties. In the long term, PETL plans to expand its U.K. assembly and manufacturing operations to enhance quality control and reduce supply chain lengths. Brill Power’s control software is stated to be engineered and validated in the U.K. With all operational data stored on U.K.-based servers.
According to Mercom’s 1H and Q2 2025 Funding and M&A Report for Energy Storage, in the first half of 2025, there were three M&A transactions in the energy storage sector, down from 14 in the first half of 2024.
In August, FlexGen Power System, a provider of battery energy storage solutions and energy management software, announced the acquisition of a significant portion of Powin’s business.
