The need to move beyond 12 V in automotive systems has been apparent for years, but now, finally, consensus seems to have emerged that 48 V is the answer. Making the transition brings huge opportunities as well as many challenges.
What you’ll learn:
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Why manufacturers, especially in Germany, are embracing 48 V.
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The huge opportunities for electrification in the 48-V platform.
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The challenges, especially in EMC, from higher-voltage systems and how to overcome them.
For more than a decade, the automotive industry has anticipated a shift in low-voltage architectures. That future has now arrived. Across Europe — and particularly in Germany — 48-V power systems have moved from experimental curiosity to mainstream electrical architecture.
American, Korean, and Chinese OEMs are rapidly following, treating 48 V not as an optional subsystem, but as a fundamental inflection point comparable to the adoption of CAN bus, the transition to 800-V traction drives, and the migration from brushed machines to permanent-magnet BLDC technology.
As integrated belt-starter-generator (iBSG) systems matured, the limitations of 12-V architectures became evident: 12 V can’t deliver high power without untenable current levels. Harnesses, fusing, contactors and connectors become large, costly, and thermally constrained at 250 to 350 A.
On the other hand, 48 V provides 4X the power at the same current, enabling significantly higher instantaneous energy transfer without excessive copper. Moreover, 48 V remains below the 60-V boundary that approximates safe, “low-voltage” safety practices. [While 60 V DC is a common limit for “extra-low voltage” (ELV) or “touch-safe” classifications in dry conditions, high-current systems (e.g., large battery banks for electric vehicles or microgrids) even at 48 V can still pose a significant hazard if proper safety measures are ignored.]
How Does 48 V Lead to Smaller Electromechanical Components?
Copper reduction is often cited as the main benefit of 48 V, but the most meaningful mass savings come from magnetic components. Motors scale down more aggressively than harnesses. Inductors, chokes, and filters shrink more aggressively than motors, and mechanical packaging flexibility improves thanks to increased power density.
Torque density depends on topology, materials, and cooling — not voltage alone. However, 48-V machines can use lower-gauge windings and achieve higher copper fill with reduced RMS losses. When paired with optimized stator geometries and lamination design, substantial mass savings follow.
Critical components benefiting from 48 V include differential-mode chokes, power-factor-correction (PFC) inductors (where applicable), stator windings on BLDC drives, EMI/RFI filters on 48- to 12-V converters, and high-side EMI suppression chokes.
The net effect is a meaningful decrease in weight and volume across the power-electronics and electromechanical stack.