The UK's commitment to net-zero emissions by 2050 requires more renewables and battery energy storage systems to control intermittency. The usability of these battery storage systems is however limited by a lack of understanding of how they degrade with usage. This directly leads to higher operating costs, and indirectly to financial inefficiencies that increase electricity costs. Breathe Battery Technologies ("Breathe") is a research-led technology company and a developer of advanced battery management algorithms. Through an Innovate UK project the company will be deploying battery digital twins in the cloud -- wholly digital replicates of each unique real-world battery storage system -- to support system operators. In order to achieve this rapidly, with minimum cost and during the COVID-19 restrictions, the company will be utilising Innovate UK funding to develop a novel method of extracting the necessary information from grid-connected battery energy storage systems.