H55 Successfully Completes System Safety Function Verification Testing of Integrated Energy Storage System

SION, Switzerland, April 29, 2026 /PRNewswire/ -- H55 today announced the successful completion of its System Safety Function Verification Testing, marking a key milestone in the validation of its integrated Energy Storage System (ESS) and its progress toward certification.

In the final stages toward certification, H55 successfully validated its Energy Storage System (ESS) in a fully integrated configuration, bringing together all critical subsystems into a complete and operational architecture. The test setup included Battery Modules (BMs), Battery Management Units (BMUs), Energy Flow Counter (EFC), Protection and Power Distribution Unit (PPDU) and the Charge Control Unit (CCU).

The campaign focused on validating system-level performance, communication integrity, and—critically—safety functionality under real operating conditions. The results confirmed robust and reliable coordination across all subsystems, ensuring stable and predictable system behavior across a range of scenarios.

A key outcome of the campaign was the successful verification of critical safety functions at system level, including the automatic and controlled disconnection of power under predefined fault or off-nominal conditions—an essential capability for safe operation in aviation environments. 

Beyond hardware validation, this milestone represents a significant step in de-risking H55's software verification and certification roadmap, with all system safety functions performing as expected within an integrated architecture.

"This milestone represents a major step in de-risking both our technology and our certification roadmap," said Anthony D'Ambrisi, Head of H55's Design Organization. "By validating system-level safety functions in a fully integrated architecture, we are demonstrating readiness for certification—not just at component level, but as a complete system. This is an important step toward industrialization and large-scale deployment."

Unlike many emerging players developing systems in isolation, H55's ESS has been engineered in alignment with certification requirements from the outset, in close coordination with aviation authorities including EASA. The system is developed to aerospace-grade standards, well beyond experimental or "permit-to-fly" approaches.

With more than a decade of experience in electric aviation, H55's safety philosophy goes beyond managing failure—focusing instead on detecting, controlling, and mitigating risks before they escalate. This approach enables a higher level of system reliability and is fundamental to achieving certification in demanding aviation environments.

The successful completion of this campaign marks a critical step in bringing H55's technology from validation to deployment. With active programs underway and growing demand for certified electric propulsion solutions, H55 is positioned to support aircraft manufacturers and operators in the transition toward electrified flight.

As the aviation industry accelerates toward decarbonization, H55's integrated and certifiable energy storage systems are enabling a new generation of electric aircraft—designed not just to fly, but to scale.

About H55

H55 is a Swiss-based company specializing in certified electric propulsion and certification-grade energy storage systems for aviation. The company enables electric aviation to scale by transforming commercial lithium cells into aviation safe Energy Storage Systems that regulators approve, insurers underwrite, and OEMs can deploy repeatedly as a certified propulsion platform across aircraft programs. This is achieved through independent cell characterization, rigorous incoming screening, redundant safety architectures, and regulator-aligned testing designed around worst-case failure scenarios.

Founded as the technological legacy of the Solar Impulse program, H55 builds on more than two decades of hands-on electric aviation experience. The company has designed, built, and flown multiple electric aircraft and has accumulated more than 2,000 hours of fully electric flight with zero battery-related incidents—providing the operational depth required to execute certification-grade programs, not merely comply with them.

H55 benefits from a strong and experienced leadership team that combines deep expertise in scaling technology companies with hands-on operational execution. Together, these capabilities support a reliable transition from certified design to repeatable series manufacturing. H55's platform-based approach, in which certification evidence compounds across programs, reduces adoption risk while facilitating the capital-efficient deployment of electric and hybrid-electric aircraft.

Press Contact
H55 : Axelle Krummenacher - axelle.krummenacher@h55.ch -
+41 79 464 2260

H55 SA
Route de l'Aéroport 10
1950 Sion
Switzerland
www.h55.ch

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