As Europe accelerates the transition toward battery-based energy and mobility systems, securing access to critical raw materials (CRMs) becomes increasingly important. In addition to primary extraction, end-of-life products represent a largely untapped resource base for secondary raw materials. This study investigates the urban mining potential of CRMs, focusing on cobalt as a representative example, to support a resilient and sustainable European battery ecosystem. Using a top-down approach, products containing CRMs are identified based on literature and industry data. Publicly available databases such as EUROSTAT, PRODCOM, UN COMTRADE, and ULJAS are analyzed to quantify material flows and estimate the stock of cobalt embedded in products within the EU. By linking trade data with material-specific content assumptions, temporal trends in imports and exports are assessed to identify potential accumulation within the European system. Results indicate a clear surplus of cobalt imports over exports, suggesting a growing in-use stock and highlighting significant urban mining potential across various product groups. However, the analysis is subject to considerable uncertainty due to limitations in trade data, including incomplete reporting, confidentiality constraints, and aggregated product classifications that require assumptions for material content estimation. The study does not aim to provide a definitive material flow analysis but rather proposes a transferable methodology for continuously monitoring CRM stocks using annually available data. The findings underline the relevance of secondary raw material sources for reducing import dependencies. Future work will focus on assessing the economic and ecological feasibility of recovering these materials within emerging circular supply chains.