Do mild hybrids have two batteries?

Mild Hybrid systems are indeed equipped with two batteries: the traditional 12V lead-acid battery and an additional 48V lithium-ion battery. The 12V battery primarily powers the vehicle's conventional electronic devices, such as lighting and audio systems, while the 48V battery supports higher-power electrical loads, including the air conditioning compressor, active chassis system, and regenerative braking function. The 48V system works in conjunction with the engine through a belt-driven starter generator (BSG), providing auxiliary torque during vehicle launch and acceleration while recovering kinetic energy during deceleration to enhance fuel efficiency. However, mild hybrid systems cannot propel the vehicle using electric power alone; their fundamental purpose remains optimizing the performance and energy consumption of conventional internal combustion engines. It's important to note that the fuel economy benefits of 48V mild hybrid systems vary with driving conditions, and advertised claims of "up to one-third reduction in fuel consumption" require comprehensive evaluation against real-world operating scenarios.