Why is 48V better than 12V?

The 48V electrical system has significant advantages over the traditional 12V system, mainly reflected in three aspects: power output, energy efficiency improvement, and technical scalability. First, under the same power, the current of the 48V system is only one-fourth that of the 12V system, which greatly reduces the wiring harness size and energy loss (I²R loss). For example, when driving a 2.5kW electric air conditioner, the current of the 48V line is only about 52A, while the 12V system requires 208A. This not only reduces the risk of heat generation but also saves wire costs by about 30%. Second, 48V supports the integration of higher-power devices such as electric turbocharging, active suspension, and steer-by-wire systems. In addition, 48V still falls into the category of safe low voltage (below 60V), eliminating the need for the complex insulation protection required by high-voltage systems and balancing cost and safety. For market applications, 48V mild hybrid systems have expanded from MHEV to the BEV field. Through coexistence with the 12V system via DC-DC converters, high-load devices (such as HVAC compressors) are gradually migrated. Despite electromagnetic compatibility challenges, as a transitional technology, 48V excels in fuel economy (improving by 10%-15%) and emission reduction, making it the mainstream choice for car manufacturers to meet electrification demands.