Chinese energy storage manufacturer Sunwoda has successfully completed a large-scale fire test (LSFT) on its “5 MWh Liquid Cooling ESS” product, with independent observers present throughout the process.

Aimed at validating the product’s safety performance, the test was conducted under more stringent conditions than typical real-world deployment, in line with international standards including ANSI/CAN/UL 9540A:2026 Sixth Edition and CSA/ANSI C800:2025. CSA Group carried out the test, while Atar Fire’s Fire Protection Engineer reviewed the process to ensure rigor and result credibility.

The test configuration included five full-scale 5 MWh Liquid Cooling ESS systems—one initiating unit and four target units—placed with a minimum spacing of 15 cm, much denser than normal. All systems were fully charged to 100%, and active fire suppression systems were disabled. For the initiating unit, explosion vent panels and ventilation panels were opened, and thermal barrier materials were removed to fully test thermal runaway propagation.

Test results showed that the initiating unit experienced thermal runaway and sustained combustion for over 12 hours. Notably, the fire was effectively contained, with no propagation to adjacent target units, and the structural integrity of the systems was maintained throughout the test.