A new testing protocol from UL Solutions addresses the demand of fire service organizations for enhanced evaluations of residential battery energy storage systems (BESS).

With the advent and increased uptake of BESS technology, UL Solutions has been addressing the associated fire safety concerns by working with fire protection and battery experts, original equipment manufacturers, code authorities and other key stakeholders to enhance the test methods for evaluating thermal runaway fire propagation in these systems. The recently released UL 9540B Outline of Investigation for Large-Scale Fire Test for Residential Battery Energy Storage Systems includes a testing protocol with a robust ignition scenario and enhanced acceptance criteria for BESS in residential settings.

The new protocol is intended to complement UL 9540, the Standard for Energy Storage Systems and Equipment, and UL 9540A, the Standard for Test Method for Evaluating Thermal Runaway Fire Propagation in Battery Energy Storage Systems. UL 9540B evaluates the fire propagation behavior of residential BESS and works in concert with UL 9540 and UL 9540A to provide a holistic approach to safety and fire behavior.

The test sequence can generate large-scale fire data for fire officials to assist them in evaluating residential BESS installations. Both UL 9540B testing and UL 9540A fire propagation testing will be implemented to determine compliance with BESS installation codes and standards such as the National Fire Protection Association 855 standard and the International Fire Code.