48Vsystem

A 48V system, in automotive and industrial contexts, denotes an electrical architecture that uses a 48-volt direct-current bus to power auxiliary systems and mild-hybrid propulsion. It typically coexists with a traditional 12V distribution and an energy-storage device.

Core components include a 48V energy storage (lead‑acid or lithium‑ion chemistry), power electronics such as a DC‑DC converter and protection devices, and high‑voltage actuation like a belt‑integrated starter/generator (BISG) or integrated starter‑generator (ISG). Additional functions may include an electric supercharger or turbo, an electric water pump, and electrified climate control modules.

History and adoption: The concept evolved from earlier 42V studies and gained traction in the 2010s as a cost‑effective path to mild hybrids without full high‑voltage systems. Automakers including Mercedes‑Benz, BMW, Audi, Volvo, and Ford have adopted 48V architectures.

Advantages: The higher voltage allows higher power delivery with lower current, enabling engine start/stop, smooth restart, recuperation, torque assist, and electric boosting of auxiliaries. It supports electrified thermal management and high‑demand devices while allowing lighter wiring compared with a pure 12V system.

Challenges: Integration with 12V systems, safety and insulation requirements for high voltage, added components and cooling needs, and the need for common standards and qualification processes.

Outlook: The 48V approach remains a standard enabler for mild hybrids and is expanding across model lines, with ongoing developments in energy storage, power electronics, and system integration.