As thermal runaway and other safety incidents in BESS facilities draw increasing concern, more rigorous and standardised safety testing is needed. The open-door fire test was developed to meet this requirement. It features four test challenges:
- All open-door combustion: The container doors remained fully open throughout the test, creating an unrestrained combustion environment with intensified oxygen flow – far more severe than traditional closed-door scenarios
- 15 cm minimum spacing: the storage systems were placed side by side and back to back with just 15 cm spacing. Despite flames at over 1300°C, no thermal propagation occurred, proving effective close-range isolation.
- Fire suppression system deactivated: all fire suppression systems were deactivated. The system relied solely on passive fire protection to withstand prolonged intense fire, demonstrating autonomous fire resistance and reliability.
- 100% state of charge: the system was tested at full capacity to maximise thermal energy release, validating the system’s reliability and stability under the harshest conditions.
Results
Conducted by UL Solutions and witnessed by certified US fire protection engineers and customers, the test strictly adhered to UL 9540A and NFPA 855 safety standards.
Despite undergoing 15 hours of full combustion, the system structure remained intact, with no fire propagation to any of the three adjacent containers. This result validates Hithium’s multi-layered passive safety architecture and thermal isolation capabilities, even under the most extreme conditions. Hithium plans to continue to advance safety performance through technology and global collaboration.
This article first appeared in Modern Power Systems magazine.
