SigenStack passes extreme fire test, demonstrating safety in C&I energy storage

The modular system design approach of Sigenergy’s SigenStack has now been verified by full-scale fire testing and third-party validation. Its architecture demonstrates a compelling direction for mitigating thermal risk and enhancing system-level resilience for commercial and industrial (C&I) energy storage.

As energy storage systems continue to scale across C&I sectors, safety has become a top priority ─ particularly in densely deployed, high-capacity installations. In an effort to validate the resilience of its system under real-world stress, energy technology company Sigenergy recently conducted a full-scale combustion test on its flagship C&I solution, SigenStack, under deliberately extreme conditions.

The test simulated a worst-case scenario involving cell-level thermal runaway escalating into sustained open-flame combustion. What set this evaluation apart was the intentional deactivation of all active safety mechanisms. There were no fire suppression systems, pressure relief valves, or software-based smoke and temperature sensors. The system had to rely solely on its passive structural design.

To initiate the event, 25% of the cells within a battery pack were artificially heated. Full-size production units were tested using real-world installation parameters, with just 20 cm of clearance front-to-back and 30 cm side-to-side. Despite cell temperatures exceeding 300 C, the fire remained fully contained within the affected pack. Adjacent packs stayed below 31 C, with no signs of thermal propagation, electrical faults, or structural damage.

Post-test inspection confirmed that the battery management unit remained intact, no short circuits occurred, and surrounding modules showed no heat-related degradation. These outcomes validate the effectiveness of SigenStack’s modular and thermally isolated architecture, which emphasizes risk prevention over post-ignition suppression.

The findings reinforce conclusions presented in the white paper “Comprehensive Safety Protection for C&I Energy Storage Systems,” jointly published by Sigenergy and global assurance provider Intertek. The report outlines key safety challenges ─ including thermal runaway, fire mitigation, and system complexity ─ and highlights SigenStack as a model for resilient and scalable design.

SigenStack complies with major international safety certifications, including UL 9540A, IEC 62619, and GB/T 36276, confirming its readiness for global deployment. Efficiency testing further demonstrated operational performance above 95%.

Instead of depending on reactive fire control, SigenStack adopts a comprehensive six-layer protection strategy. This includes early warning sensors, insulation barriers, and pressure relief design ─ all working together to prevent, isolate, and contain thermal events at the source.

With proven fire containment and robust certification, Sigenergy is positioning SigenStack as a future-ready energy storage system: modular, intelligent, and engineered for safety.