EU consortium aims to fit a 22 kW bidirectional on-board charger in a 4-liter package

A European consortium led by Fraunhofer IZM is developing a highly compact 22-kilowatt on-board charger (OBC) with a volume of just four litres, significantly smaller than the current market average of 12 litres. This innovative charger utilises monolithically integrated bidirectional gallium nitride (GaN) semiconductors supplied by Infineon, enabling both forward and reverse current flow within a single device. The project, known as HiPower 5.0, is funded by the EU and will run from August 2025 to June 2028, aiming to deliver improvements in efficiency, cost, and size for electric vehicle charging systems. The key technological advancement lies in the use of bidirectional GaN switches, which replace conventional designs that require separate semiconductors for each current direction. By integrating multiple electronic components directly into the circuit boards, the consortium reduces electrical path lengths and parasitic losses, resulting in a more compact and efficient charger. Fraunhofer IZM’s approach treats the charger design holistically, focusing on system-wide optimisation rather than individual components, which marks a departure from traditional engineering methods. HiPower 5.0 brings together a broad coalition of partners from across Europe, including two original equipment manufacturers (OEMs), 21 tier-one and tier-two suppliers, six power electronics experts, ten universities, and seven research institutions. Among the notable participants are Infineon, Mercedes-Benz, Mahle, Valeo, Siemens, Vitesco Technologies, TDK Electronics, and AVL. The project aims to address six different use cases spanning automotive and marine shipping sectors, reflecting a diverse application scope for the technology. With a total budget of €33.7 million, the initiative receives substantial backing from the EU and member states, including €5.74 million from the German Federal Ministry of Research, Technology, and Space and €0.12 million from the Free State of Saxony. The development of this compact, bidirectional charger could have significant implications for the future of electric vehicle infrastructure, potentially enabling faster, more efficient charging and vehicle-to-grid capabilities within a smaller physical footprint.