UL 9540A Test Report Template (PDF)

UL 9540A is the definitive test method developed by Underwriters Laboratories to evaluate how thermal runaway propagates from a single defective cell to adjacent cells or modules within a battery energy storage system. Unlike generic safety standards, UL 9540A focuses specifically on system-level fire propagation behavior under controlled fault conditions—such as induced thermal runaway via external heating or overcharge—and mandates rigorous instrumentation, environmental controls, and data fidelity. The Test Report Template serves as the official output artifact, structuring raw test data, observations, photographic/video evidence, and engineering interpretations into a format acceptable for regulatory review, permitting (e.g., by fire marshals or building departments), and insurance underwriting. It includes mandatory sections for test configuration (cell chemistry, module/pack layout, spacing, ventilation), triggering methodology, real-time thermal and gas monitoring, failure sequence chronology, and pass/fail determinations based on defined acceptance criteria (e.g., time-to-propagation, maximum temperature rise, flame spread distance). Importantly, the template does not prescribe pass/fail thresholds itself—those are derived from UL 9540’s system evaluation requirements—but provides the evidentiary foundation upon which such evaluations rest.