The battery, although central to the green transition of road transport, currently suffers from a supply chain that lacks traceability, sustainability, resiliency, and circularity. Critical Raw Materials (CRMs) are essential for battery manufacturing. The explosive growth of electric vehicles, driven by climate neutrality policy objectives, will pressure the CRM supply chain and increase EU dependency on third countries, resulting in decreased competitiveness for EU automotive and battery manufacturers. Implementing the digital battery passport (DBP) concept in the battery value chain could resolve these issues. The main goal of the BASE project is to develop, validate, and implement a working DBP service, as mandated by the “Regulation.” This will be achieved by exploiting data collected through a number of constantly evolving tools and methods, ensuring a transparent, secure, and cost-efficient platform operation, while also catalyzing the growth of circular businesses. BASE will develop transparent methodologies to calculate battery performance and ESGE indicators, ensuring traceability down to the CRM level throughout the entire battery value chain. In the physical domain, this will be achieved through the mass balancing approach. On the data management side, by exploiting distributed ledger technology, BASE will ensure built-in data authenticity verification along the value chain, with no data duplication, avoiding data manipulation, assuring privacy by design, and promoting data interoperability. The DBP will provide up-to-date and accurate data on battery performance indicators, remaining useful life, dismantling, material composition, and safety. This will allow for an increase in the useful service life of batteries and more efficient recycling, which will enhance resource efficiency, reduce waste, and decrease EU dependency on CRMs from third countries. The applicability of the DBP will be demonstrated through four pilot use cases.