[China, November 17, 2025] Huawei Digital Power's Commercial and Industrial Hybrid Cooling Grid Forming Energy Storage System (C&I GFM ESS) has successfully passed a stringent extreme ignition test witnessed by TÜV Rheinland. Conducted at a national key fire safety lab, the test is the industry's first fire assessment of an ESS in compliance with the latest UL 9540A:2025 standard. Its exceptionally rigorous conditions establish a new safety benchmark for the sector.
Extreme Challenge: Rigorous Test Environment
The test was designed to create the industry’s most demanding verification environment, evaluating the safety performance of ESSs under extreme ignition scenarios. A pack-level overcharge method was used to trigger simultaneous thermal runaway in 60 battery cells—simulating a "worst-case upon ignition" scenario. Compared with tests involving only single or a few cells, the severity of this assessment increases exponentially.
Further rigor was ensured through the following conditions:
1. The open-door ignition test method specified in UL 9540A:2025 is employed to maximize oxygen availability.
2. All packs are fully charged to 100% SOC.
3. All proactive and passive fire suppression systems are disabled during testing, requiring the ESSs to rely solely on their intrinsic design to withstand combustion at full energy capacity.
Proven Strength: Five-Level Protection System
Under these extreme conditions, Huawei's C&I GFM ESS demonstrated outstanding safety performance, supported by its innovative five-level protection design.
1. Inter-cell thermal isolation: It effectively slows down the thermal runaway propagation between cells, providing the first defense for system safety.
2. All-metal pack enclosure: The enclosure can withstand temperatures higher than 1500°C, maintaining structural integrity even under intense fire to minimize damage.
3. Positive-pressure oxygen blocking and directional smoke exhaust: This innovative design redirects combustibles, significantly reducing fire impact.
4. Fireproof labyrinth design: All ESS sealing surfaces feature a labyrinth structure to effectively prevent flame spread.
5. Enhanced container fire resistance: The container is armored to provide comprehensive fire protection.
Data Evidence: Key Indicators Demonstrating Excellent Performance
Test data robustly validates the safety and reliability of Huawei's C&I GFM ESS. When the fire temperature reached 961°C, the highest cell temperature of an adjacent ESS was only 45.3°C, well below the threshold for opening the cell explosion-proof valve. The system fully complied with UL 9540A:2025 requirements, with no fire propagation between units.
The recorded peak heat release rate (HRR) was 3 MW. Total combustion lasted less than three hours before self-extinguishing. Under open-door burning conditions, the system rapidly managed heat release, demonstrating superior thermal management capability.
By successfully passing this extreme ignition test, Huawei Digital Power has set a new benchmark for safety in commercial and industrial energy storage, marking a milestone for the large scale, secure deployment and sustainable development of the industry.