The Mercedes Power Converter isolates the high-voltage voltage from the battery status.

Mercedes is working on new technology to provide a constant 800-volt voltage in electric vehicles. With current technology, the system voltage depends directly on the condition of the battery cells. Mercedes plans to use a so-called power converter in the future, which eliminates this dependence by employing individual microconverters for each cell unit.

Image: Mercedes-Benz

Mercedes has announced a new architecture for electric vehicles that aims to eliminate the dependence of high-voltage voltage on battery condition through the use of new power electronics.

In conventional electric vehicles, the system voltage is determined by the number of battery cells connected in series. As the charge level decreases, this voltage drops during operation. Aging or weakened cells also affect the performance of the entire battery pack.

Decentralized microconverters instead of conventional cell connections

Mercedes’ so-called Power Converters are designed to function as individual decentralized microconverters that control battery cells or cell groups. Multiple Power Converters connected in parallel can coordinate energy flows and prevent voltage fluctuations by maintaining a stable DC high voltage.

Weaker cells are selectively relieved by the control system, thereby improving overall efficiency. Additionally, functions such as AC and DC charging as well as bidirectional charging can be integrated into the electronics. Currently, a power output of up to three kilowatts is possible.

Elimination of the onboard charger saves weight and space

The main advantage of this design lies in combining previously separate components. Since the microconverters handle the conversion of AC and DC voltages directly, the traditional separate charger (on-board charger) in the vehicle can be eliminated. This saves weight, space, and production costs.

At the same time, the drive inverter receives a constant 800-volt input and no longer needs to be designed for fluctuating input voltages. This improves its efficiency and makes it easier to use identical drive components in different drive concepts.

Potential for OTA Features and Digital Business Models

Alongside ongoing questions about the repair complexity of more advanced technologies directly on the battery, another aspect emerges: since the microconverters already come equipped with the necessary physical components out of the factory, not only functions like two-way charging but also the maximum charging power can be controlled purely through software. This likely opens up new opportunities for manufacturers to offer paid over-the-air updates.