AI-Generated Image for Illustration Purposes
The transition to 800V EVs affects the entire powertrain, including the power electronics. In IDTechEx’s report, Power Electronics for Electric Vehicles 2026-2036: Technologies, Markets, and Forecasts, these trends are analysed and used to forecast the adoption of wide bandgap semiconductors SiC and GaN, as well as the entire power electronics market for electric vehicles (EV).
The automotive industry is converging on 800V platforms for battery electric vehicles (BEVs), when earlier generations of vehicles were 400V. While 400V will undoubtedly have a part to play in the next decade, the advantages of 800V platforms are undeniable and, in most cases, worth the re-engineering of the powertrain to accommodate them.
Firstly, a higher voltage means the battery can charge at higher power while using less current. For consumers who want charging to be as quick as refuelling an internal combustion engine (ICE) vehicle, 800V vehicles can deliver higher average and peak power. While this is generally the case, other parameters in the car and also in the charger will determine the actual charging speed.
Secondly, since the voltage is much higher, significantly less current is required to deliver the same amount of power to the traction inverter and the motor. The result is fewer losses and greater efficiency, allowing for either a slight increase in range or a reduction in battery size (and therefore weight and cost). Either case is advantageous, and SiC MOSFETs are much more efficient than Si IGBTs at 800V due to their material and device properties, so the transition to 800V EVs and SiC MOSFETs goes hand in hand.
Finally, since less current flows through the vehicle’s wiring harnesses, the diameter of the harnesses can be significantly reduced. Copper is heavy and expensive, so a theoretical halving of the wiring harness diameter (excluding insulation and cooling requirements) delivers a compounded cost and weight saving. Even though BEVs are much more efficient than ICE vehicles, squeezing out extra efficiency at lower cost benefits consumers and OEMs alike, many of which have struggled with the profitability of their BEVs.
There Are Different Ways to Achieve 400V to 800V Compatibility
There is one glaring issue with building an 800V platform EV: the majority of DC chargers worldwide are 400V, meaning an onboard system is needed to convert the 400V DC from the charger to 800V DC to charge the high-voltage battery. Without such a system, most DC chargers cannot be used. Mercedes controversially did not include an 800V booster in its announcement of the Mercedes CLA EV earlier in 2025, though this was later reversed.
IDTechEx has identified three key ways to achieve 400V to 800V charging compatibility, each with its own advantages and disadvantages. While each system is complex, IDTechEx has found that battery switching, DC boost converters, and traction-integrated onboard chargers are the three main approaches from OEMs and tier-one suppliers to achieve 800V compatibility.
Boost converters are the most straightforward method, in which an additional DC-DC converter is installed on the vehicle to boost the voltage from 400V to 800V before feeding it into the high-voltage battery. While this is simple, adding this extra unit is also costly, especially when the space in a vehicle is already limited. This is the method used in the Porsche Taycan.
By switching the cell configuration during charging, the battery pack can be charged in a mix of series and parallel connections to match the DC charger’s incoming voltage. The GMC Hummer and Tesla Cybertruck run variants of this technique to ensure charging compatibility.
Finally, traction-integrated onboard chargers are a unique way to boost the voltage without the need for a separate DC-DC converter. The windings in the electric motor act as a filter inductance and increase the voltage of the incoming DC from the charger without requiring a separate DC-DC converter. This is the approach used by Hyundai and Kia, and multiple tier-one suppliers have similar methods to boost voltage.
Comments are closed.