Complete system design, including mechanical, electrical and thermal control, is critical to realize the benefits of Li-Ion technology in automotive batteries. In order to meet the technical requirements in a demanding automotive environment efficient thermal and electric control strategies have to be developed and implemented. These strategies must deliver on two opposing goals: a wide operation window to support optimal vehicle performance and protection of the battery from states which could negatively influence reliability, safety and long term endurance. This is true for all applications ranging from small batteries in Mild Hybrid Vehicles to large batteries for Full Electric Vehicles. Due to the wide variety of performance requirements in these vehicle applications the control strategies must be flexible and adaptable. The special requirements of these applications and the applied technologies will be discussed.