Mercedes-Benz is developing an innovative power electronics system that could change how future electric vehicles manage battery energy, charging and power delivery. Called the Power Converter, the technology is designed to maintain a constant high-voltage output of up to 800 volts, regardless of the battery’s state of charge or the condition of individual cells.
The new system uses decentralised, software-controlled micro-converters to manage energy flows at the level of individual battery cells or cell groups. By reducing the dependence between battery voltage and the vehicle’s high-voltage electrical system, Mercedes aims to make future EV architectures more efficient, flexible and compact.
The technology could also eliminate the need for certain conventional charging components, simplify electric powertrain development and enable new charging functions, including bidirectional charging.
How Mercedes-Benz’s Power Converter Technology Works
In conventional electric vehicles, the system voltage is largely determined by the number of battery cells connected in series. As the battery’s state of charge decreases, its operating voltage also drops. Ageing and differences in the condition of individual cells can further affect the battery pack’s overall performance.
Mercedes wants to overcome these limitations with its new Power Converter architecture.
Instead of relying entirely on a traditional battery cell configuration to deliver the required high voltage, the system uses multiple decentralised micro-converters. Each converter manages the energy flow of an individual cell or a group of cells, while several units connected in parallel work together to provide a stable high-voltage DC output.
This approach allows the vehicle’s electrical system to remain largely independent of fluctuations in battery voltage.
One important advantage is the ability to manage weaker battery cells more intelligently. The control system can selectively reduce the load on cells that are performing less efficiently, helping balance the battery pack and potentially improve its overall energy utilisation.
The current generation of Mercedes’ Power Converter technology delivers up to 3 kW of power and supports both AC and DC applications.
Constant 800-Volt Output Could Improve EV Efficiency
Maintaining a stable 800-volt supply could offer several advantages for future electric vehicles.
Today, power electronics must accommodate variations in battery voltage throughout the charging and discharging process. This adds complexity to the design of components such as traction inverters, which convert battery power into the electricity needed by the electric motors.
With the Power Converter, the traction inverter could receive a consistent high-voltage input of up to 800 volts.
This would allow Mercedes to optimise the inverter around a more predictable operating voltage rather than designing it to handle a wider range of changing inputs. The result could be improved power electronics efficiency, reduced engineering complexity and greater opportunities to standardise components across different electric vehicle platforms.
The technology could also give Mercedes more freedom when designing battery packs. Since the required system voltage would no longer depend as heavily on the number of cells connected in series, battery architectures could become more modular and adaptable to different vehicle sizes and performance requirements.
Mercedes Could Eliminate the Conventional Onboard Charger
Another significant benefit could come from combining functions that are currently handled by separate electronic components.
In conventional EVs, the onboard charger (OBC) converts incoming AC electricity into DC power suitable for charging the battery. Other power electronics handle different voltage conversion and energy management tasks.
Mercedes’ Power Converter could integrate several of these functions into a more unified system, potentially eliminating the need for a separate conventional onboard charger.
That would create opportunities to reduce component count, save weight and free up valuable installation space inside the vehicle. Fewer separate components could also help reduce manufacturing costs and simplify future electric powertrain architectures.
For electric vehicles, reducing weight and improving the efficiency of electrical systems can contribute to better overall energy consumption and potentially longer driving ranges.
However, the actual range improvements will depend on how the technology is implemented in production vehicles and how much efficiency it delivers under real-world driving conditions.
Bidirectional Charging and Software-Controlled Features
The Power Converter could also play an important role in expanding charging capabilities.
Mercedes’ technology is being developed with support for AC charging, DC charging and bidirectional energy transfer. The latter allows electricity to flow in both directions, opening the door to applications such as Vehicle-to-Home (V2H) and Vehicle-to-Grid (V2G).
With V2H, an electric vehicle can supply electricity to a home, potentially providing backup power or helping owners use stored energy more efficiently. V2G takes the concept further by allowing compatible vehicles to send electricity back to the wider power grid.
An interesting aspect of the Power Converter is that some of these capabilities could be enabled or adjusted through software rather than requiring additional hardware.
This creates opportunities for over-the-air (OTA) updates and software-controlled charging functions. Mercedes could potentially introduce new features or adjust charging capabilities after a vehicle has left the factory.
It could also create new digital business models, including optional software features. However, whether Mercedes will offer paid OTA upgrades for specific Power Converter functions has not been confirmed.
More Complex Battery Electronics Could Bring New Challenges
Despite its potential advantages, the technology also raises some questions.
Integrating numerous micro-converters directly into the battery architecture could increase electronic complexity. More components inside the battery pack could introduce additional challenges related to reliability, thermal management, diagnostics and long-term maintenance.
Repairability is another important consideration. If an individual converter fails, the cost and complexity of identifying and replacing the affected component could influence the overall ownership experience.
Mercedes will also need to demonstrate that the benefits of decentralised power conversion outweigh the additional hardware and control-system complexity.
