The charging method of 48V mild hybrid batteries primarily relies on the vehicle's own energy recovery system, eliminating the need for external charging equipment. Such hybrid systems convert energy into electrical power and store it in the battery through excess power generated during engine operation or kinetic energy recovered during vehicle deceleration or braking. For instance, during low-speed driving or coasting, the integrated starter-generator (ISG) functions as a generator, transforming mechanical energy into the electrical power required by the 48V battery. Additionally, engines in some models automatically replenish the battery when operating within their high-efficiency range (e.g., during steady-speed cruising). It is important to note that the 48V mild hybrid system features a relatively small battery capacity. Its primary design purpose is to assist the combustion engine by enhancing start-stop smoothness and optimizing fuel efficiency, rather than enabling long-range electric driving. Under normal driving conditions, the system autonomously maintains battery charge. If the battery becomes depleted due to prolonged inactivity, recharging can be achieved by starting the engine to idle or undertaking a short drive.
