Preparing for a 48-volt REVIVAL

Four times the voltage means four times the power-and far less cost than “full” hybrid systems. 48/12-V is poised to take on the WLTP.

More than a decade after the widely anticipated 42-volt electrical revolution died-the victim of increasingly efficient 12-volt components, wiring strategies, and digital controls-demand for greater on-board electrical capacity is again driving plans for higher-voltage systems. This time 48-V (or more accurately, dual-voltage 48-V/12-V) hybrid systems soon to enter the market will deliver performance and functionality at a fraction of the cost of high-voltage systems.

A key to the emergence of 48-V hybrids is the move by European Union regulators to replace the current NEDC test protocol with the new Worldwide Harmonized Light Vehicles Test Procedure in 2017. The WLTP cycle was devised to more accurately reflect real-world driving and vehicles' expanding electronic feature content. Engineers say WLTP compliance is more challenging than the NEDC; the benefits of 12-V stop-start systems are diminished by nearly half, for example.