From 18 February 2027, Article 11 of the EU Batteries Regulation (EU) 2023/1542 requires portable batteries in products sold in the EU to be readily removable and replaceable by the end user. That means commercially available tools only, with no proprietary tools, heat or solvents, and no software that blocks a compatible replacement. This guide explains how to classify products and batteries, who must be able to replace them, and how the eight partial derogation categories in Commission Delegated Regulation (EU) 2026/1770 work, including wearables, electric toys, food probes and ATEX equipment. It also covers the five-year spare battery duty that runs from the last unit of a model placed on the market, and the products that sit outside Article 11, such as smartphones and tablets. A seven-step readiness checklist helps design, engineering and compliance teams review each in-scope model before the deadline