eWAVE brings together 18 research, technology and shipbuilding experts to mature High-Voltage (HV) technology for electric vessels for future uptake in European shipbuilding sector, using efficient HV electric modular battery and distribution systems. It will research, develop and demonstrate solutions for sustainable maritime and inland vessels. However, the widespread adoption of such HV technology is hindered by several obstacles (e.g. current battery systems’ energy density, safety concerns, durable & sustainable materials), and, finally, economic viability/sustainability. This will be achieved by using new high-energy-density high-nickel-content batteries for waterborne applications in a lightweight housing made of recyclable thermoplastics, wired and wireless BMS solutions and multi-level converters that provide the required scalability for vessel systems up to 1MWh and far beyond. The battery system will be fostered by an integral safety system concept considering thermal runaway & ventilation, supported by an integrated real-time condition monitoring system using novel SoC/SoH algorithms and SoS estimation. The key results of eWAVE will be validated via laboratory and real-life vessel demonstrators. The applicability of the system will be investigated across multiple vessel types using an efficient modular digital twin to maximize industry uptake. To further improve circularity and sustainability of maritime battery systems, eWAVE will explore bio-based battery housings, a design for dismantling and recycling, the creation of a battery passport concept for the maritime sector, and potential 2nd life applications for the batteries. eWAVE’s HV technology solutions, tools and methods are expected to significantly improve the safety, efficiency, and sustainability of battery systems in shipping, thus supporting transition to all-electric shipping and contributing to the reduction of the environmental footprint of waterborne transport in the EU and far beyond.