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UL 9540A Test Method

Testing the fire safety hazards associated with propagating thermal runaway within battery systems.

Battery energy storage system inside building

Watch the video: UL 9450A Test Method

Energy storage system testing is changing. Learn why July 15, 2022, could be a milestone on your company's safety journey.

New requirements are changing how you need to test your battery energy storage systems. A revised edition of UL 9540 includes updates for large-scale fire testing. It goes into effect on July 15, 2022. Starting then, you may have to change how you evaluate your ESS.

Help ensure your thermal runway fire propagation testing will be accepted by code authorities.

Increased deployment of energy storage systems has led to field failures in past years, heightening awareness of the dangers of thermal runaway. As this technology moves closer to our homes and places of work, battery manufacturers need to consider and evaluate the likelihood of fire propagation.

We developed the UL 9540A, the Standard for Test Method for Evaluating Thermal Runaway Fire Propagation in Battery Energy Storage Systems, to help manufacturers have a means of proving compliance with the new regulations. Leveraging our long practice of developing standards with our vast experience in the battery, energy storage and fire industries, we worked with regulators to understand their concerns and deliver a viable test method to accelerate the adoption of this innovative technology.

As a leading global safety science company and a leader in energy storage technology testing, we serve the entire industry value chain through our comprehensive regulatory knowledge and our regional laboratories.

We designed services to help reduce the complexities associated with creating energy storage products. We support you in your drive to deliver safer and better technologies to the global marketplace. 

Discover the UL 9540A Test Method

The UL 9540A Test Method is referenced within UL 9540, the Standard for Energy Storage Systems and Equipment, the American and Canadian National Standard for Safety for Energy Storage Systems and Equipment, the International Code Council (ICC) International Fire Code (IFC), National Fire Protection Association NFPA 855, Standard for the Installation of Stationary Energy Storage Systems, as well as a wide variety of local, state and international building and fire codes.

UL 9540A was developed to address safety concerns identified by the building codes and the fire service in the United States. One of the primary concerns that NFPA 855 (and the fire codes) tries to address is the potential fire and explosion hazards associated with a battery system, such as an uninterrupted power supply (UPS) or battery energy storage system (BESS). To control this hazard, the codes specify very stringent limits for energy capacity and separation distances. For example, the current ICC International Fire Code (2021 IFC) allows an individual BESS unit not to exceed 50 kWh and to have a maximum quantity of systems totaling 600 kWh of energy per indoor fire area (battery room) or outdoor, near exposures. It also limits individual residential systems not to exceed 20kWh and to have a maximum quantity of up to 80 kWh. These BESS units must be installed with a three foot (one meter) separation distance between units and between units and any wall. The latest IFC and NFPA 855 editions allow the code authority to approve larger individual BESS units and separation distances less than three feet based on large-scale fire testing conducted in accordance with the UL 9540A Test Method.

Results from the UL 9540A Test Method address the following key issues identified by building codes and the fire service:

  • BESS installation instructions
  • Installation ventilation requirements
  • Effectiveness of fire protection (integral or external)
  • Fire service strategy and tactics

We will work with you to understand your products and develop an individualized test plan that works for your company and meets your needs.

We are a leader in battery safety technology

We are a leader in battery safety technology. We helped develop the stationary battery standard, ANSI/CAN UL 1973, the Standard for Batteries for Use in Stationary and Motive Auxiliary Power Applications, the energy storage system standard ANSI/CAN UL 9540, Energy Storage Systems and Equipment, as well as the recent UL 9540A Test Method. We offer:

  • Unparalleled availability of our full fire testing facilities — no need for subcontracting
  • Experienced engineering and research teams that can help develop insights using in-depth knowledge of battery chemistries and fire suppression
  • Demonstrable track record of success serving organizations and entities such as fire departments as well as electrical and building inspectors

UL 9540A Test Method Brings Clarity to Insurance and Fire Mitigation Professionals

UL Solutions' new test method for evaluating thermal runaway fire propagation in BESS will bring clarity on the performance of a BESS under a possible thermal event that can occur in the life of the system.

Watch our webinar
Download our brochures

UL 9540A Database Information Sheet and Authorization Form

65.89 KB

UL9540A Test Method Information Sheet

769.31 KB

Performance of Batteries in Grid Connected Energy Storage Systems

2.35 MB

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