HiTHIUM has completed the world’s first open-door large-scale fire test of its 6.25MWh long-duration energy storage (LDES) system, marking a major milestone in battery safety validation at higher energy levels.
The test was conducted under the supervision of UL Solutions, U.S. Authorities Having Jurisdiction, and fire protection engineers, in strict compliance with the latest UL 9540A 2025 and NFPA 855-2026 standards. Results demonstrated stable and controllable safety performance of the high-energy-density system under extreme real-world conditions.
The fire test simulated the most severe scenarios, with container doors fully open to maximize oxygen supply, adjacent containers placed just 15 cm apart, the system operating at 100% state of charge, and all active fire suppression systems disabled. The setup was designed to validate the intrinsic safety of HiTHIUM’s battery architecture.
HiTHIUM’s ∞Power 6.25MWh system, powered by ultra-large-capacity 1175Ah battery cells, demonstrated three key safety capabilities: controlled energy release without explosions, containment of fire without thermal propagation to adjacent containers, and structural stability without collapse under prolonged high-temperature exposure. The system’s multi-layer safety architecture spans cell, module, and system levels, incorporating directional venting, dual pressure relief valves, fire-resistant enclosures, and reinforced structural design.
The successful test represents a critical breakthrough in validating safety for next-generation high-capacity energy storage systems, strengthening the foundation for large-scale deployment of long-duration energy storage technologies.
HiTHIUM stated that long-duration energy storage remains a strategic priority and that the company will continue advancing safety standards and collaborating with industry partners to support scalable, reliable, and secure energy storage solutions for the global energy transition.
