Electrifying Aviation

The certification-grade energy platform

H55 exists to accelerate the inevitable transition to electric aviation by solving the single biggest roadblock: certification-grade energy storage. We engineer, architect and certify energy storage that is predictable, provably safe, and trusted by authorities, insurers, and OEMs. Electric aviation scales on certification.

H55 is the first company to achieve regulatory approval

The safety test campaign for battery modules in a CS-23 fixed-wing aircraft was conducted under global aviation safety and environmental standards agreed by EASA.

Completed on December 19, 2025, the EASA-approved and witnessed campaign confirms completion of the hardest milestone in electric aviation certification, establishing certification-grade, aviation-safe propulsion battery systems and defining the reference standard against which future programs will be assessed. Testing demonstrated certification-grade evidence that commercial lithium battery cells can be integrated into aviation propulsion battery modules, safely containing worst-case failure scenarios, including thermal runaway without propagation.
Certification is the product.

Battery Engineering on Cell-Level

Our Energy Storage System is based on a certification-driven approach to battery design.

H55’s patented technology architecture allows for monitoring of every cell individually. By designing protection, monitoring, and mitigation directly at cell level — rather than relying on pack-level assumptions — we have built a fundamentally different Energy Storage System. This cell-level architecture enables effective protection at the point of origin, while optimizing battery efficiency, performance, and long-term reliability — all essential requirements for certifiable electric aviation. This is the foundation of our certification-grade safety architecture, designed around worst-case failure scenarios and regulator-approved containment — governing how energy is safely stored, monitored, and delivered in flight.

Safety is not a feature of the system — it is the system.

Our ESS is an agnostic platform

Powering next-generation aircraft

One modular ESS platform compounds certification evidence across electric, hybrid, hydrogen-electric, STOL, VTOL, and regional aircraft. This enables manufacturers to advance without reinventing the safety core each time. We are not betting on which aircraft will win — we are building the energy-storage platform they all depend upon. By solving thermal safety, redundancy, and worst-case failure containment, H55 gives OEMs, regulators, and insurers the confidence required to scale clean flight. The certification-grade ESS platform shortens certification cycles, reduces program risk, and enables OEMs to move faster.

H55 is not a concept or a roadmap - it is already flying and building regulatory proof

With the sale of Bristell B23 Energic and active programs with CAE and Pratt & Whitney, H55 is in the skies continuing to build certification evidence, flight hours and data. We are building on deep experience.

Operational flight time compounds certification evidence.

20+

years of electric aviation experience

2000+

hours of fully electric flight (0 incidents)

6+

aircraft designed, built and flown

22+

patents electric flight & air worthiness

Bristell B23 Energic

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