XIAMEN, China – June 5, 2025 – In a major breakthrough for battery energy storage system (BESS) safety worldwide, Hithium, a global leader in energy storage technology, has successfully completed the world’s first all open-door large-scale fire test of its advanced ∞Block 5MWh BESS. The event marks a historic milestone in safety validation and underscores the company’s commitment to setting new industry standards in fire safety, thermal management, and risk mitigation.
As the global energy storage sector expands rapidly to support renewable integration and grid stabilization, thermal runaway incidents and fire hazards in BESS systems have drawn increasing scrutiny. Hithium’s test provides groundbreaking insight into passive fire protection mechanisms, reshaping expectations for future safety protocols in large-scale storage deployments.
The Industry’s Toughest Fire Test
What sets this test apart is its all open-door configuration—a deliberate deviation from traditional fire containment practices. Unlike standard closed-door fire assessments, Hithium conducted the test with container doors fully open, exposing the system to an unrestricted supply of oxygen and creating a combustion environment of unprecedented intensity.
The fire scenario subjected the system to temperatures exceeding 1300°C, simulating the worst-case environment. Despite this, no thermal propagation occurred, demonstrating that even in an ultra-aggressive fire setting, Hithium’s system prevents the spread of fire between containers.
Four Critical Test Challenges
The fire test incorporated four rigorous testing conditions, each designed to push the safety architecture of the ∞Block system to its absolute limit:
- All Open-Door Combustion
The container doors were kept open throughout the test, allowing for maximum airflow and oxygen supply. This elevated the test’s severity beyond typical containment-based fire scenarios, ensuring that passive safety—not suppression—was the focus. - 15cm Proximity Placement
BESS units were placed just 15 centimeters apart, both side-by-side and back-to-back, maximizing the risk of heat transfer. Despite this extreme proximity, no fire spread occurred, proving the system’s thermal isolation barriers effective in real-world high-density deployments. - Fire Suppression Systems Deactivated
To test autonomous fire resistance, all active fire suppression systems were disabled. The system relied entirely on multi-layered passive fire protection to resist combustion—an approach that emphasizes intrinsic safety over reactive mechanisms. - 100% State of Charge (SOC)
The test was conducted with the system fully charged, maximizing available thermal energy. This stress-tested the system at peak internal energy, validating its structural integrity and thermal stability even under maximum load and fire stress.
Certified by Global Safety Authorities
The test was conducted under the supervision of UL Solutions, a globally recognized safety certification authority, and complied strictly with the UL 9540A and NFPA 855 standards—the gold standard for BESS fire safety. It was witnessed by certified U.S. fire protection engineers and Hithium’s global customers, further reinforcing the credibility and transparency of the results.
Over the course of the 15-hour full combustion test, the ∞Block 5MWh system maintained complete structural integrity, with zero propagation to three adjacent units. This result validates the robustness of Hithium’s safety-centric design, which includes compartmentalized modules, thermal insulation layers, and heat dissipation mechanisms designed specifically for extreme event containment.
A New Safety Benchmark for the Industry
This pioneering achievement by Hithium redefines what is possible in BESS safety performance. It not only raises the bar for thermal runaway resistance but also demonstrates the viability of passive-only safety systems, offering a blueprint for manufacturers seeking to minimize system complexity and improve reliability.
“This fire test proves the value of investing in passive fire protection from the ground up,” said a spokesperson from Hithium’s engineering team. “Our multi-level safety design doesn’t rely on reaction—it prevents fire from the very beginning, even under the most extreme conditions.”
Supporting the Future of Clean Energy with Safer Storage
As utilities, grid operators, and developers scale up battery storage installations to match the growth of solar, wind, and distributed generation, safety and reliability become mission-critical. Hithium’s successful demonstration provides confidence for large-scale BESS deployments in urban, commercial, and utility-scale environments.
Moreover, the company’s collaboration with regulatory bodies and testing agencies provides valuable data and guidance for future safety certifications, helping shape international standards for battery storage system design and deployment.
Ongoing Innovation and Global Commitment
Hithium emphasizes that this test is just the beginning. The company plans to continue investing in next-generation safety technologies, enhanced material science, and international partnerships aimed at accelerating the energy transition safely and sustainably.
“Our mission is not just to lead in technology, but to lead responsibly,” the company’s leadership stated. “We’re committed to helping the global industry grow—not just fast, but safe.”
By demonstrating the exceptional fire resistance of its ∞Block 5MWh BESS under extreme open-door combustion scenarios, Hithium has set a new industry benchmark for what battery safety can—and should—look like in the real world.
