Helios Horizon Flies Electric Plane Fitted With Solid-State Batteries

Overview

• Helios Horizon completed short piloted flights to validate installation of solid-state battery packs and to confirm sustained propulsion and weight‑and‑balance after the swap.
• The project reports the new cells deliver about 410 watt‑hours per kilogram versus the aircraft’s prior roughly 260 Wh/kg lithium‑ion cells, a change it says improves range and endurance.
• Helios Horizon says the batteries charge much faster and are more stable because they replace liquid electrolytes with solid materials, which the team says reduces fire and thermal‑runaway risk.
• The aircraft can accept common AC charging without special infrastructure and the team describes in‑flight energy recovery from solar panels and by windmilling the propeller to extend flight time.
• All performance figures and future projections come from Helios Horizon’s own release and have not yet been independently verified, and the team says it will continue system optimization ahead of planned stratospheric flights later this year.