MAN tests 3,000-amp charging

MAN Truck & Bus and its partners have managed to maintain a stable charging current of 3,000 amps on a test bench. An intensity that could, in the long term, make it possible to reach a charging power of 3 MW and recover, in just 10 to 15 minutes, the energy needed to travel 400 kilometres.

However, there is one important point to note: this is not yet a truck actually charging at 3 MW. The tests were carried out on test benches at the Technical University of Munich and at the Fraunhofer ISE institute in Freiburg. They nevertheless demonstrate that very high-current charging is progressing rapidly and could profoundly change the operation of electric heavy-duty vehicles.

From 1,000 to 3,000 amps

In July 2024, MAN had already presented, as part of the NEFTON project, an eTGX capable of charging at a power of one megawatt. With NEFTON 3000, the manufacturer and its partners are now going much further by reaching, for the first time, a stable current of 3,000 amps.

This testing campaign made it possible to collect data on the thermal behaviour of the system, switching components, cooling and the safety architecture. The objective is to validate the technical solutions necessary to sustainably support charging powers of up to 3 MW.

The engineers notably had to optimise the electrical circuit in order to reduce resistance, because the passage of such a high current generates significant thermal losses.

The cables, connectors and distribution units have therefore been equipped with liquid cooling specifically designed to keep the components within an acceptable temperature range. The contactors and switching devices have also been adapted so that they can safely switch very high currents.

Integration on board a truck represents another challenge. The system will have to comply with the space, weight and safety constraints specific to industrial vehicles.

400 kilometres of range recovered in 15 minutes

In the long term, this technology could allow an electric truck to recover, in 10 to 15 minutes, enough energy to travel approximately 400 kilometres.

Such performance would bring the downtime of an electric heavy-duty vehicle closer to that required to refuel. Above all, it would open up new possibilities for activities whose organisation allows neither overnight charging nor prolonged downtime.

3 MW charging could thus meet the needs of transport operations with two drivers, particularly intensive missions or vehicles that need to quickly get back on the road between two rotations.

It could also make it possible to reduce the capacity of the batteries carried on board. With a sufficiently dense network of ultra-fast charging stations, some trucks could use smaller batteries and carry out several intermediate charges during the day. A solution that could reduce the weight, cost and quantity of raw materials required for their manufacture.

Batteries and infrastructure still to be developed

3 MW charging is nevertheless not ready to be deployed immediately. To absorb such power levels, a new generation of batteries will have to be developed. Cell chemistry, module design and electrical architecture will all have to be adapted to the constraints imposed by such high currents.

The infrastructure will also have to evolve. Delivering several megawatts to a truck indeed requires grid connections and particularly powerful charging equipment.

The NEFTON project brings together MAN Truck & Bus, AVL, the Technical University of Munich, the Fraunhofer ISE institute, Prettl Electronics Automotive, the Research Center for Energy Economics (FfE) and Deggendorf University of Applied Sciences. It benefited from funding from the German Federal Ministry for Economic Affairs and Climate Protection, with the support of the DLR project management organisation.

At the end of this research programme, the TRATON Group will continue developing high-current charging systems capable of moving closer to series production. Work will also focus on bidirectional charging and the MCS standard, with currents of up to 3,000 amps.

Megawatt charging is therefore only just beginning. But between the first MAN eTGX charged at 1 MW in 2024 and this circuit now capable of supporting 3,000 amps, the technology is moving fast. Very, very fast.