Mercedes-Benz ELF: a novel approach to charging electric vehicles

• Holistic research approach: the ELF experimental charging vehicle combines vehicle innovations with infrastructure concepts for a seamless, intelligent charging experience
• Dual fast-charging capability with MCS and CCS: research into performance limits and development of future series solutions
• Bidirectional charging with AC and DC: vehicle becomes an energy storage device for buildings, electrical consumers and power grid

Electric mobility is a key component on the road to decarbonisation. With its focus on local CO_₂-free driving, intelligent charging and holistic resource conservation, Mercedes-Benz is making the case for sustainable innovation with its ELF experimental charging vehicle. ELF is a nickname derived from the German term Experimental-Lade-Fahrzeug – which translates to Experimental Charging Vehicle. Electric mobility is more than just technology – it stands for responsibility towards the environment, society and future generations. But local CO₂-emission-free driving alone is not enough.

Charging must also be efficient, intelligent and sustainable. That is why Mercedes‑Benz is consistently working on innovative charging solutions for the home, workplace and public spaces – and actively shaping the future of charging. In 2021, the company was one of the first car manufacturers to launch Plug & Charge, a function that made fast charging easier than ever before. With its own MB.CHARGE Public charging service, which is fully integrated into the vehicle, Mercedes‑Benz set standards for connected public charging in 2019. An integral part of this charging service is Green Charging in Europe, Canada and the U.S., which specifically promotes the use of electricity from renewable energies. 

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ELF is more than a vehicle – it’s a symbol of a bold new era in charging. With the Experimental Charging Vehicle, Mercedes‑Benz demonstrates what happens when visionary technology, courageous ideas and passionate teamwork come together. This mobile charging lab unites ultra-fast, bidirectional, solar, inductive and conductive charging in a holistic concept that doesn’t just test the limits of what’s possible – it redefines them.

Behind ELF stands an interdisciplinary team driven by dedication and innovation, working to make electric mobility more convenient, efficient, and sustainable. With ELF, Mercedes‑Benz makes an emotional statement for progress – underlining its role as a pioneer in mobility and setting milestones in the charging of electric vehicles. 

Fast charging: at the limits of what is feasible

Fast charging is the key to the everyday usability of electric mobility. With the ELF experimental vehicle, Mercedes‑Benz is exploring the limits of what is technically feasible – both in the vehicle and at the charging station. To this end, the experimental vehicle is equipped with two fast charging systems that cover different areas of application: 

• MCS connector (Megawatt Charging System)
  Originally developed for heavy-duty transport, this system allows charging capacities in the megawatt range. In the ELF, MCS serves as a research tool for testing the thermal resilience and performance limits of high-voltage batteries, power electronics, charging cables and other components under extreme conditions. The findings are being incorporated into the development of long-distance vehicles and fleet solutions with short downtimes. 
• CCS connector (Combined Charging System)

CCS is used as the standard for passenger cars to test near-series components such as cables, connectors, cooling and charge control under everyday conditions. Mercedes-Benz is testing the technical limits of CCS in order to create the conditions for even higher charging capacities. The ELF can achieve a charging capacity of up to 900 kW. This means that 100 kWh can be charged in 10 minutes. The vehicle simulates typical charging scenarios that occur in everyday customer use, such as at fast charging stations along motorways or in urban areas. The components used, such as the battery, charging control and CCS hardware, are already close to series production and will be incorporated into future Mercedes‑Benz models. 

With the combination of MCS and CCS, Mercedes‑Benz is pursuing a dual research approach: on the one hand, new technological horizons are being explored and the technology of the future is being developed. On the other hand, the series production readiness of existing systems and in turn, the charging experience of today is being improved. One example of how the knowledge gained is being directly incorporated into the development of future series models is the CONCEPT AMG GT XX technology programme.

The concept vehicle sets new standards in the field of high-performance charging. It can recharge enough energy for a range of around 400 kilometres (WLTP) within five minutes. The CONCEPT AMG GT XX achieves a very high average charging power of 850 kW at 1,000 amps over a large range of the charging curve. Following its record-breaking drive with a legendary finish in Nardò, the CONCEPT AMG GT XX achieved a peak charging power of 1,041 kW during megawatt charging. 

Mercedes‑Benz teamed up with Alpitronic, the European market leader in high-power charging, to develop a prototype high-performance charging station for the CONCEPT AMG GT XX’s record-breaking drive. For the first time, it can transmit currents of up to 1,000 amps via a CCS cable – twice as much as was previously possible. This was enabled by using an MCS charging station originally designed for trucks, in which the truck cable was replaced by a CCS cable. The cooling capacity in the plug and cable was retained, allowing for higher power outputs. This charging system was not developed separately but together with the vehicle. On a test bench in Stuttgart-Untertürkheim, the development team simulated real-life charging scenarios in which vehicle components and charging station were tested and validated together. This demonstrates the holistic development approach taken by Mercedes‑Benz. 

The findings from the prototype charging station are being directly incorporated into the development of a new generation of high-performance fast chargers, which are to be used at Mercedes‑Benz charging parks. Customers will therefore benefit from extremely fast charging processes, with charging times that differ only minimally from conventional refuelling processes. Shorter charging times mean greater flexibility when travelling and a significant increase in convenience in everyday life. Mercedes‑Benz is thus underlining its innovative strength and aims to set new standards for public charging in the future.

Bidirectional charging – returning energy; shaping the future

Bidirectional charging is more than just a technological option – it is a strategic lever for the energy transition. With the ELF, Mercedes‑Benz is exploring the full potential of this key technology: not only absorbing electricity, but also feeding it into the home (Vehicle-to-Home; V2H), into the grid (Vehicle-to-Grid; V2G) or directly to electrical devices (Vehicle-to-Load; V2L). This allows electric vehicles to become an active part of a sustainable energy system. In the future, they will offer customers greater independence and potential cost savings. The ELF tests bidirectional charging in real-world scenarios. The findings are fed directly into the series development of future models. 

The ELF is capable of both AC and DC bidirectional charging: 

• AC (alternating current) enables the power supply of electrical devices (V2L) and the return of energy via a bidirectional AC wallbox directly into the home network – for applications such as Vehicle-to-Home (V2H) or Vehicle-to-Building (V2B) or into the public power grid (V2G). An advantage is that the infrastructure is more cost-effective. A disadvantage is that standardisation becomes more complex as the vehicle must meet the requirements of different power grids. 
• DC (direct current) allows for direct energy recovery with a bidirectional DC wallbox into the public power grid (V2G) and directly into the home or building network (V2H; V2B), depending on the infrastructure used. An advantage is high efficiency, especially when using a hybrid inverter for bidirectional charging. With photovoltaics and home storage, it is easier to meet grid requirements. A possible disadvantage could be the slightly higher investment costs for the charging infrastructure. 

Mercedes‑Benz brings not only research but also experience to the table, as demonstrated by the successful introduction of bidirectional charging in Japan with the CHAdeMO standard. Mercedes‑Benz is also preparing specific customer offers for the CCS standard. The new all-electric CLA with EQ Technology and the new GLC with EQ Technology are already technically equipped for bidirectional charging with a compatible DC wallbox. In the course of 2026, Mercedes‑Benz will launch its first services for bidirectional charging in Germany, France and the UK.

Other markets will follow. The MB.CHARGE Home offer combines the vehicle, bidirectional wallbox, green electricity tariff and energy market access. The aim is to reduce household costs and support grid stability. Thanks to intelligent control and an app, vehicles can not only charge in a cost-optimised manner but also feed energy back into the home network or power grid. This turns electric cars into active energy storage devices and contributes to the energy transition. 

General customer benefits of bidirectional charging

Bidirectional charging opens up a new level of independence, cost-effectiveness and sustainability for customers:

• Self-sufficiency & emergency power supply: a typical Mercedes‑Benz high-voltage battery in an electric vehicle with a capacity of 70–100 kWh can fully supply an average single-family household with electricity for two to four days (V2H) – ideal in the event of power outages or as a supplement to a photovoltaic system. In addition, the vehicle can also serve as a mobile power source for electrical devices via V2L (Vehicle-to-Load) and, for example, flexibly supply tools or household appliances with energy. 

• Reducing the carbon footprint: solar power is used in a targeted manner. Surplus solar power can be temporarily stored in the high-voltage battery for later use in the home (V2H). This helps to reduce CO₂ emissions.
• Energy cost savings: In combination with intelligent energy management, electricity costs can be significantly reduced. Depending on the usage scenario, savings of around 500 euros per year are possible, which corresponds to approximately 10,000 free kilometres. 

Electric vehicles as the key to the energy transition – bidirectional charging as a game changer

Electric vehicles play a central role in the energy transition, not only as local CO₂-free means of transport, but also as mobile storage for renewable energy. Through bidirectional charging (vehicle-to-grid; V2G), they can absorb excess energy from wind and solar power plants and feed it back into the grid when needed. This opens up new opportunities for grid stability, security of supply and better use of renewable energy sources. 

Idea for a virtual energy account – flexible uses for electricity generated at home

A forward-looking approach in the context of the increasing integration of public charging and home charging is the idea of a “virtual energy account”. This refers to the possibility of using solar power generated not only at home but also flexibly on the go. The principle: customers receive energy credits in a virtual account for surplus electricity from their photovoltaic system and for grid-friendly charging and discharging at home. The accumulated credits could be used flexibly at a later date, either at home or on the go at public Mercedes‑Benz charging stations. 

By using such a virtual account, customers could use the electricity they generate more economically and reduce their dependence on fluctuating electricity prices. The technological prerequisite for this would be a closed ecosystem and deep integration of the vehicle, charging infrastructure and cloud platform. With the MB.CHARGE charging ecosystem, Mercedes‑Benz already has such a digital backbone: it connects charging points, energy flows and user profiles, enabling intelligent control and billing regardless of the location of the charging process.

The aim of this vision is to offer customers maximum flexibility while reducing the load on the electricity grid. Mercedes‑Benz is committed to creating the appropriate regulatory framework to enable this use of bidirectional charging with V2G. One possibility would be exemptions from grid fees for temporarily stored electricity, similar to the current regulation for large-scale storage facilities in the market introduction phase. 

Inductive charging – wirelessly into the future

With the ELF, Mercedes‑Benz is also testing charging without cables using induction. This involves transferring electrical energy to the vehicle without a physical connection via a charging system integrated into the ground. This technology offers great potential, especially at home and for fleet applications, as it makes charging more convenient and virtually invisible. 

The ELF is equipped with an inductive charging system based on the principle of magnetic resonance. The charging power is currently 11 kW alternating current (AC), which corresponds to a typical wallbox. As part of the project, the technology is being tested for everyday usability, efficiency and compatibility with different vehicle heights and positions for various mobility concepts such as premium vehicles, robot taxi approaches and fleet solutions. Particular attention is being paid to user-friendliness and international scalability. In markets such as Asia and South Africa, the topic of “hands-free charging” is meeting with particular interest. There, inductive charging is seen as a convenient solution for cramped or unsafe charging environments. 

Conductive charging – for efficient energy transfer

Automated conductive charging via the vehicle floor is an innovative method for charging electric vehicles conveniently and efficiently. Conductive charging uses special charging plates in the floor that communicate with the vehicle. They help the driver or the parking assistant to park the vehicle correctly and initiate the charging process. Energy is transferred via a direct physical connection using a connector in the vehicle floor. The charging power is currently 11 kW AC. In the ELF, particular attention has been paid to the installation of the connector in the vehicle floor and the positioning requirements – the vehicle must be positioned in a specific area above the charging plate in order to start the charging process, which requires targeted parking. 

Like inductive charging, automatic conductive charging via the underbody offers numerous advantages: drivers do not have to connect or disconnect cables, which significantly increases comfort and user-friendliness. In addition, the risk of cable wear and possible electrical hazards is minimised. Conductive charging is particularly suitable for barrier-free applications or tight parking spaces. Another advantage is the aesthetic integration of the charging infrastructure into the floor, which results in a tidy appearance and requires less space than traditional charging stations. What’s more, the effective radius is the same as that of wired systems and slightly better than that of inductive solutions. 

Automated charging – rethinking infrastructure with robotics

In addition to increasing charging power, automation of the charging process using robotics is also becoming increasingly important. Robot-assisted charging offers a promising solution, particularly in the area of fast charging, where high currents and large cable cross-sections are used. Mercedes‑Benz is therefore researching automated charging systems that enable vehicles to be connected to the charging infrastructure precisely, safely and without any manual intervention. This is a decisive step, especially for fleet operators, barrier-free mobility concepts and the premium segment. 

These developments are closely linked to the work of Mercedes‑Benz Mobility’s in-house Charging Unit. The Charging Unit is also responsible for the global rollout of the Mercedes‑Benz Charging Network, a brand-owned fast-charging network with a focus on convenience, reliability and premium service for drivers of electric vehicles of all brands.