Experts agree on need for large-scale fire testing of battery energy storage systems

October 9, 2025

Chris Clonts

Participants in the discussion, from l to r: Mike Anderson, senior compliance engineering manager with Hithium; Abid Anwer, staff regulatory engineer, Tesla; Mark Boone, national property manager, AEGIS; Kevin Fok, director of compliance, LG Energy Solutions; and moderator LaTanya Schwalb, principal engineer for energy and industrial automation at UL Solutions. (Chris Clonts)

A panel of four battery testing experts from different fields agreed that large scale fire testing, as called for in a proposed update to testing standard UL 9540A, could help address confusion among consumers, battery companies and insurers.

Moderated by LaTanya Schwalb, principal engineer for energy and industrial automation at UL Solutions, the panel discussion held at the Battery Show North America underscored the need for a current standard and for standards to adapt more quickly to new battery chemistries and technologies.

Mark Boone, national property manager for AEGIS Insurance Services, said large-scale testing, in which systems are intentionally allowed or encouraged to catch fire, could help head off what he called a “market-hardening event” that causes significant reputational damage to a company or industry. One example: A lithium-ion battery warehouse fire in Holland, Michigan that required the work of nine fire departments to extinguish.

Kevin Fok, director of compliance, LG Energy Solutions, said modeling with a limited data set was not very convincing. “We just really had to do the tests in order to prove that maybe it would not be enclosure to enclosure propagation.”

“Another part of the reason for the questioning as well is because you may have unit level testing that [would not match] the propagation, but then for one reason or another, you would have an incident and you would have the whole enclosure consumed in the fire.”

Schwalb said there are so many variables that an improved large-scale fire testing (LSFT) standard could create better understanding. “Manufacturers do design their battery energy storage systems with a level of safety in mind. That's why we start off with that cell certification. We talked about … the importance of safety in terms of even down to the component level such as cells, but even moving forward to the pack level, module level, as well as the whole unit of the battery energy storage system. And as you’ve heard, there can still be incidents that occur in the field, even if a system may have been certified or not have been certified,” she said.

“It may have been caused by the cells, may not have been caused by the cells,” she said. “And so when it comes to those situations, in order to determine what would happen in the real world, I think this is the driver and the demand of this industry in order to say, Okay, you say that, you know that you've done 9540A testing, you know that you don't have propagation, but let's find out what could potentially happen in case there's a catastrophic failure. And this is where a large-scale fire testing plan has come into play.”

Mike Anderson, senior compliance engineering manager for Hithium, talked about the value of his company having completed the world’s first all open-door large scale fire test.

And Abid Anwar, staff regulatory engineer at Tesla, said fire testing has always been a best practice, whether in a test standard or not. “The search for fire test has always been a good best practice, and it's very much helped build confidence in fire code officials and building code officials as we went through those review and approval processes,” he said. “Where it has been extremely helpful is it helps incorporate fire service on what a catastrophic event looks like.”