Chinese energy storage manufacturer Sunwoda has become the latest to complete a large-scale fire test (LSFT) in the presence of independent observers, after setting fire to its “5 MWh Liquid Cooling ESS” product.
Now tasked with meeting relevant international standards such as UL 9540A and CSA C800, Sunwoda said it had conducted the test in “a more rigorous format than the typical real-world implementation” as it aimed to validate its product.
The test itself was conducted with a configuration of five actual full-scale 5MWh Liquid Cooling ESS systems, including one initiating unit and four target units, with a minimum distance of 15cm, much closer than normal. All were at 100% charge and active fire suppression systems were disabled. According to the requirements, in the initiating unit, explosion vent panels and ventilation panels were opened and thermal barrier materials were removed to fully test the propagation of the thermal flood.
Sunwoda said the test was conducted in accordance with ANSI/CAN/UL 9540A:2026 Sixth Edition and CSA/ANSI C800:2025. To ensure a rigorous process and credible results, the test was conducted by CSA Group and reviewed by Atar Fire’s Fire Protection Engineer.
Results
Sunwoda said that during the LSFT, the initiating unit experienced thermal runaway and sustained combustion for more than 12 hours, yet the fire remained contained, without propagation to adjacent units, and structural integrity was maintained throughout the fire.
Sunwoda stated that the “multiple protective measures for cells, packages and systems work together to slow heat transfer, reduce thermal impact between adjacent systems and support the control of thermal runaway.”
Below are several photos provided.
