This Special Issue, "Towards a Smarter Battery Management System: 2nd Edition", presents a collection of innovative research focused on advancing battery management technologies. It highlights key advances in battery state estimation, thermal management, cell balancing, and safety diagnostics. Emerging trends such as wireless BMS, artificial intelligence integration, new battery chemistries, and second-life battery applications are prominently featured, reflecting the field's shift toward more intelligent, adaptive, and sustainable battery solutions. This reprint serves as a valuable resource for researchers, engineers, and practitioners seeking to understand and contribute to developing the next generation of smart battery management systems.