GaN4EmoBiL Unveils 800 Volt DC Charger
GaN4EmoBiL aims to cut costs for bidirectional charging in electric vehicles by using gallium nitride power semiconductors. The project, launched in 2023, targets a gap in current technologies that rely on either costly silicon carbide or less efficient silicon components. Its goal is to make bidirectional charging more accessible for the mass market.
Bidirectional charging allows EV batteries to act as energy storage units. For example, surplus solar power from a home system can be stored in an EV battery and later returned to the home or grid. This process, known as V2H or V2G, lets users earn money by selling energy during high-demand periods.
The project’s innovation centers on gallium nitride (GaN), a compound of gallium and nitrogen. Fraunhofer IAF and Ambibox have developed a power module using GaN components rated for 1,200 volts. These are mounted on an insulating substrate to handle the 800-volt class of bidirectional DC chargers.
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A demonstration of the system will appear at the PCIM Expo & Conference 2026 in Nuremberg. The showcase includes a single-phase 800-volt DC charger capable of bidirectional power transfer up to 3 kW. Jun.-Prof. Dr. Stefan Mönch, the project’s coordinator, called the design a more flexible and cost-effective alternative to traditional systems.
Unlike on-board chargers that convert AC to DC inside the vehicle, this off-board unit sits outside the EV. It weighs 5.7 kg and has a volume of 8.3 liters, making it portable. The module supports both CCS and Schuko plugs but offers lower charging capacity—3 kW versus 11 or 22 kW from standard on-board units.
The system is not a standalone charging station. It functions as a mobile converter, separate from grid-connected DC wallboxes used in V2G setups like E.ON and BMW’s iX3. By moving the AC/DC conversion hardware outside the vehicle, the design reduces size and weight while maintaining bidirectional capabilities.
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Conventional V2G solutions integrate conversion technology into bulky wallboxes. This new approach separates the hardware, allowing for a more compact system. The module’s design, while compact, doesn’t sacrifice the ability to handle high voltages.
The project’s focus on GaN aims to balance cost, efficiency, and size. Silicon carbide components are efficient but expensive, while silicon alternatives are cheaper but less so. GaN’s properties offer a middle ground, potentially lowering costs without sacrificing performance.
Fraunhofer IAF emphasizes the system’s flexibility. It can be deployed in various settings, from residential use to grid-scale applications. The module’s portability makes it suitable for temporary installations or areas where permanent infrastructure is impractical.
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Industry experts note that bidirectional charging is still emerging. While the technology exists, widespread adoption depends on cost reductions and infrastructure development. Projects like GaN4EmoBiL aim to address these barriers by refining materials and design.
The demonstrator’s specifications highlight trade-offs. Its lower power output compared to on-board systems is offset by mobility and compactness. Users might prioritize portability for certain applications over maximum charging speed.
Researchers stress that the module is a proof of concept. Scaling production and ensuring reliability under real-world conditions will be critical next steps. The project’s success could influence future EV charging standards and grid integration strategies.
