Mercedes wants to change how an EV battery 'breathes', and the on-board charger may disappear
Mercedes-Benz has unveiled Power Converter, a technology still in development that puts micro-converters next to battery cells and keeps an 800 V supply steady however full or worn the pack is. Not a production car yet, but it shows where electric drivetrains are heading.
Most EV batteries work like a chain: cells are wired in series, and the voltage at the output depends on how many cells are in that chain and how full they are. On 3 November, Mercedes-Benz showed an idea that breaks the chain. It is called Power Converter, and it appeared in a Stuttgart release about future technologies, next to two glass-display concepts.
One thing up front: this is a technology under development, not a feature arriving in showrooms tomorrow. The release names no model, price or launch date.
What it does, in plain terms
Power Converter uses programmable micro-converters that manage the energy flow of single cells or small groups of cells. Several of these modules, connected in parallel, together produce a steady high-voltage output of up to 800 V, whatever the cells' charge level or age.
On a conventional pack, voltage sags as you drain it, and one weak cell holds the others back. Here the electronics can route around it or decide how much to ask of each cell, so the rest of the car always sees the same voltage. Mercedes says the current generation delivers up to 3 kW and works with both AC and DC.
The concept is not entirely new: the company described a programmable cell-level converter back in November 2024 as a research project. What is new is that it now quotes concrete figures and presents it publicly as an option for future architectures.
Why engineers care
Mercedes lists possible gains: batteries and power electronics designed more freely, more compact and more efficient, with potentially better range and efficiency. If one hardware unit can convert AC and DC and work bidirectionally (V2H, V2G), some separate parts of today's cars could merge. electrive points out that even the conventional on-board charger could go, saving weight, space and cost. The traction inverter would always receive a constant 800 V and could be tuned for a single operating point.
The same outlet raises open questions: nobody knows yet whether more complex electronics at the battery would make repairs costlier. It also notes that if charging power or bidirectional charging are set purely in software, a manufacturer could sell paid over-the-air unlocks. That is the journalists' reading, not a promise or declared plan from Mercedes.
What we still don't know
- which model will use it first, and when;
- what it costs and how long series production takes;
- how it copes with heat, vibration and years of real-world wear;
- how a faulty module is repaired or replaced;
- whether a 3 kW converter per cell group scales to the hundreds of kilowatts a whole car needs on the road and at fast chargers.
For context, Mercedes already uses 800 V on the electric CLA, with DC charging up to 320 kW. Power Converter would be a step after that, not an immediate replacement.
What it means for drivers
In the short term, nothing changes for the car you can order today. In the medium term the direction matters: batteries that are more flexible, less sensitive to one weak cell and simpler to charge bidirectionally could mean more usable energy at home and, in principle, a longer useful battery life.
When the first models arrive, ask three concrete questions: what the battery warranty covers, what a replaced module costs, and which charging functions are included for good rather than as a subscription. Until then, treat the news as a look inside Mercedes' lab, not a reason to delay a purchase.
