Electric vehicle (EV) batteries are the cornerstone of modern electric mobility, directly influencing vehicle performance, driving range, safety, cost, and environmental sustainability. Rapid advancements in electrochemical storage technologies have enabled the widespread adoption of EVs, while simultaneously posing challenges related to energy density, charging time, degradation, and recycling. This chapter provides a comprehensive overview of battery technologies used in electric vehicles, covering fundamental principles, dominant lithium-ion chemistries, emerging battery technologies, battery management systems, degradation mechanisms, charging characteristics, and future research directions. Emphasis is placed on technical performance, grid interaction, and sustainability aspects, making this chapter relevant for researchers, engineers, and policymakers working in the EV and power systems domain.