Following two successful live fire tests in utility-scale energy storage, Sungrow has extended its extreme testing capabilities to the residential storage sector. Recently, its SBH series residential energy storage system successfully passed UL Solutions’ world’s first UL 9540B large-scale fire test, demonstrating industry-leading performance in thermal runaway management and fire spread control, establishing a new safety benchmark for residential energy storage.
UL 9540B, designed for residential storage systems under 20kWh, is recognized as the industry’s most stringent safety standard. The standard requires systems to force thermal runaway at full charge and simulate extreme fire scenarios including combustible gas accumulation, ejection, and external ignition to evaluate whether systems exhibit fire spillover, explosion, or building-level secondary risks. This places extremely high demands on system thermal insulation, gas management, thermal runaway suppression, and overall engineering design.
Under this standard, the SBH residential storage system endured extreme testing lasting an entire day and night. Facing multiple challenges including closely arranged battery units, disabled active fire suppression, continuous ignition triggering on both sides, and no intervention throughout the burning process, the SBH residential storage system successfully passed all assessments with its excellent “flame self-control capability.”
Fire Containment Without Spread – “Locking Down” Fire Risks
Through multiple safety designs including cell-level fire insulation, bottom heat dissipation, and three-dimensional pressure relief, after one SBH unit was forcibly triggered into thermal runaway and caught fire, the flames remained controlled at the pressure relief port. The maximum internal surface temperature of the two adjacent units reached only 21°C, far below the 154°C cell venting temperature. The eave temperature peaked at 35°C, far below the standard requirement of 150°C, with no fire spread.
1-Hour Extinguishment Without Reignition – Eliminating Fire at Its Inception
Leveraging rapid heat dissipation and inter-module thermal isolation capabilities from the system’s structural design, thermal runaway in the SBH residential storage system was mainly concentrated in the bottom module. Without any fire suppression intervention, open flames naturally extinguished within one hour. Subsequently, ignition was continuously triggered on both sides for 24 hours, with no reignition occurring.
No Explosion, No Projectiles – “Robust” Protection for Energy Safety
With the active fire suppression system disabled, no explosion occurred throughout the test, no structural components scattered, and the cabinet remained intact, demonstrating excellent fire resistance, explosion prevention, and structural stability.
Previously, the SBH residential storage system had passed the UL 9540A thermal runaway propagation test. Successfully passing the UL 9540B large-scale fire test marks its safety capabilities now covering the complete chain from cells to system, from thermal runaway suppression to real fire control, providing household users with higher-level safety assurance.
As a global leader in the energy storage industry, Sungrow consistently upholds the “highest standards” to defend the safety baseline of energy storage. Moving forward, Sungrow will continue advancing energy storage safety technology innovation, safeguarding worry-free household electricity with the highest standards.
