December 9, 2022

UL 9540A Fire Test Standard for Battery Energy Storage Systems

If a battery system is capable of thermal runaway, the UL 9540A test method will make it happen to show the system’s fire and explosion characteristics.
flames representing fire

Building and fire codes require testing of battery energy storage systems (BESS) to show that they do not exceed maximum allowable quantities and they allow for adequate distancing between units. UL 9540A is the consensus test method that helps prove systems comply with fire safety standards.

SEAC’s ESS Standards working group created this informational bulletin, an Introduction to UL 9540A, to show the sequence of tests used to evaluate BESS beginning with cell-level testing and continuing, as necessary, to installation-level testing.

The document includes a flowchart summarizing the performance criteria that must be met to conclude the evaluation at each level of testing. It outlines key points to share a more complete understanding of the UL 9540A test method. For those who wish to dive deeper, the file also links to a handful of additional resources including the text of UL 9540A, and a webinar, articles, and a checklist from UL.

The Introduction to UL 9540A: Standard for Test Method for Evaluating Thermal Runaway Fire Propagation in Battery Energy Storage Systems informational bulletin can help system designers, asset owners, and code officials. SEAC published the document in December 2022.

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This material is based upon work supported by the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy (EERE) under the Solar Energy and Technologies Office Award Number DE-EE0009002.0001. The views expressed herein do not necessarily represent the views of the U.S. Department of Energy or the United States Government.