Sungrow, a PV inverter and energy storage provider, says its PowerTitan 3.0 battery energy storage system (BESS) has completed a large-scale fire test under the latest UL 9540A: 2026 and CSA/ANSI C800-2025 requirements.
The company describes it as the first stacked-cell BESS with an AC-block design to pass such a test. UL Solutions conducted the test, with Fire Risk Alliance witnessing and Jensen Hughes observing. Sungrow says all three generations of the PowerTitan, from 1.0 to 3.0, passed on the first attempt.
The setup mirrored a utility-scale installation, with 28.56 megawatt-hours (MWh) of liquid-cooled PowerTitan 3.0 units and a 7.4 megawatt (MW) medium-voltage substation. Each unit combines the battery system and power converter in a single 20-foot container.
Thermal runaway did not spread from the initiating container to adjacent containers or the substation during the 7.5-hour test. The peak internal temperature in the initiating container reached 1259.8°C, while cell temperatures in adjacent containers stayed below the UL 9540A: 2026 threshold for thermal runaway.
All containers remained structurally intact, and smoke and fire effluent was collected and treated rather than released.
“This test was about verifying our safety design under real-world extreme conditions,” said Roger Li, General Manager of the Utility-Scale Product Line, Sungrow Energy Storage Business Unit, in a statement. “Safety must be engineered into the product from the beginning.
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