Did H55's Battery Modules Just Unlock the Future of EASA Electric Flight?

Swiss electric propulsion company H55 has achieved a significant regulatory milestone. The firm completed the industry's first regulator-approved propulsion battery module certification tests. This successful test sequence was supervised by the European Union Aviation Safety Agency (EASA). It directly addresses a critical safety bottleneck for the electric aviation sector. The achievement confirms that H55's battery technology meets rigorous aviation safety standards.

The Certification Breakthrough

The six-month test campaign concluded in December 2025. It was a regulator-required and authority-witnessed test sequence. The testing subjected H55's battery packs to extreme conditions. These included environmental, safety, functional, and performance evaluations.

Thermal Runaway Validation

The most critical part was the EASA thermal runaway tests. These tests proved the battery system could safely contain worst-case failures. Specifically, the system prevented fire propagation, or explosions, within the battery pack. This containment is paramount for electric aircraft battery certification. The hardware used was serial-conforming, not just prototypes. This means the tested modules were built on regulatory-approved production lines.

Impact on Electric Aircraft Commercialization

The successful testing removes a major hurdle for commercialization of electric aircraft. Proving high-energy batteries are safe has been an unresolved industry bottleneck. The milestone reduces risks for manufacturers, operators, and investors. It helps accelerate the financing of new electric aircraft programs.

Setting the Standard for Safety

H55's patented Energy Storage System (ESS) uses advanced design. It features monitoring, redundancy, and hazard mitigation at the cell level. This design ensures containment of extreme failure conditions. The battery packs are being certified to the CS-23 standard. This standard covers larger aircraft, up to 19 seats, including utility and commuter planes. This is a step beyond the smaller CS-LSA category, which includes aircraft like the Pipistrel Velis Electro. The first version of the H55 battery pack will have a capacity of 104 kWh.

Global Regulatory Horizon

This H55 EASA regulatory milestone has global implications. The test results will be shared with the Federal Aviation Administration (FAA). This is part of a FAA EASA mutual recognition arrangement. Sharing the data will support and accelerate H55's US certification activities. This collaboration helps establish consistent lithium battery safety standards worldwide. It pushes the entire industry toward sustainable aviation propulsion.

• The successful tests set a new industry benchmark for electric aviation safety.
• The achievement validates the use of commercial lithium battery cells in propulsion systems.
• It confirms H55's ability to manufacture systems to certification standards.

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