Last month, Vitesco Technologies and Renault Group announced they had joined forces to develop and produce power electronics in a so-called “One Box” for electric and hybrid powertrains.

While the tech inside the boxes would be complex, consisting of a DC/DC converter, inverter, and onboard charger, the idea of keeping all the parts in one box seems brutally simple.

But, by combining all the parts into one unit, the companies are promising improved performance and lower prices. In this week's Mobility Moments, we spoke to Stephane Fregosi, Head of Electronic Controls, Vitesco Technologies, to find out more about One Box.

One Box combines several functions in a space- and cost-optimized way in one housing. Depending on customer requirements, various functions are built in.

The high-voltage box (HV box) acts as an energy conversion hub on board the electric car and combines functions for operating voltages of up to 800 V: First, it regulates the AC charging process from the AC grid by converting it into DC voltage and thus feeding the high-voltage battery. The system can handle AC power from 7.2 to 22 kW. Secondly, the HV box manages the energy distribution from the high-voltage battery to the energy consumers as well as the DC fast-charging function at high-energy charging stations in the triple-digit kW range. Thirdly, the high-voltage box supplies the vehicle’s12 V vehicle electrical system with energy.

Since previously separate modules are integrated now in one box, the overall weight, volume, and costs of the vehicle’s electronics can be significantly reduced. By combining the different functions in a single component, the water cooling of the high-voltage electronics and the wiring of the individual elements can be made considerably more efficient.

Another important advantage is that the new, lighter, smaller, and more cost-effective high-voltage box is also considerably more robust and fail-safe, for example, because cable connections can be eliminated.

The exact savings, however, can only be calculated after development, as Renault envisages different applications with different high voltage levels, all covered by the same "one-box" family:

Renault Group will bring to this development partnership its expertise in the field of electric and hybrid vehicles, while Vitesco Technologies will contribute its long-standing competencies and experience in the field of vehicle electronics and related products. The Renault Group, for example, is a leader in the development of electric vehicle chargers, while Vitesco Technologies is a leading manufacturer in the development and production of DC/DC converters for electric and hybrid vehicles. These electronics from Vitesco Technologies are already in series production by vehicle manufacturers several times.

The goal is a key electronic unit that combines all components in one housing: the DC/DC converter, the onboard charger OBC and the inverter. Renault Group and Vitesco Technologies teams will define the products and assembly processes of this “One Box” by integrating the latest technologies to ensure the best level of competitiveness in terms of performance and cost. 

So, joint development and production have to be done until the first SOP of the Renault Group in 2026. 

Yes, but the delivery scope of Vitesco Technologies depends on the system architecture and the integration of functions. It varies from entire systems to subsystems and components. 

As part of this partnership, Renault Group will at the same time provide Vitesco Technologies with a multi-year contract for the power electronics of Renault's hybrid vehicles. In addition, Vitesco Technologies will supply to the Renault Group a “High Voltage Box”, which combines the DC/DC converter and charger, for battery electric vehicles as of 2025.

Yes, there is a clear trend to combine the onboard charger with the DC/DC converter inside of one box. Optional there will be also the “Charging Communication” (Communication between vehicle and charging station part of this so-called HV-Box.

The future is electric. According to experts, around 40% of new vehicles will have an electrified drive by 2025, and this figure will rise to 70% by 2030. In the EU, it will be even faster due to the latest requirements and pending decisions (phasing out of internal combustion engines) of the EU Commission.