Wärtsilä’s Quantum3 energy storage system passes three major fire safety and explosion tests

Finnish engineering firm Wärtsilä Energy Storage has detailed three fire safety and explosion tests carried out on its Quantum3 battery energy storage system (BESS).

The tests are critical for all large-scale battery storage concepts, and the testing on Quantum3 has some added importance given it has one of the few fully integrated AC blocks packaged in a compact 20-foot container.

The testing carried out included UL 9540A unit-level testing, Large Scale Fire Testing (CSA TS-800 / C800), and proprietary Active Ignition Mitigation System (AIMS) testing CSA Group participated in the “planning and witnessed the execution of all three tests for third-party verification. While not directly disclosed, the system appears to have been tested at CSA Group’s facility in Kunshan, China, with photos showing (储能检测) which translate to “Energy Storage Testing”.

Both Wärtsilä and CSA Group confirmed the three tests, that were said to be designed to simulate worst-case fire and/or explosion scenarios, were successful. The testing aimed to confirm Quantum3’s ability to contain thermal runaway events, and in doing so, actively prevent fire propagation to nearby energy storage, and further mitigate risks associated with flammable gas build-up.

Wärtsilä had previously succesfully tested its Quantum2 system and its AIMS techology earlier in 2025.

The press release stated the following results:

“UL 9540A Testing: Quantum3 met all necessary performance requirements, demonstrating that if a battery cell were to enter thermal runaway, the event would not spread to adjacent modules nor enclosures. No external flaming occurred, and no explosion hazards were exhibited.
“Large Scale Fire Testing: Under controlled conditions and in compliance with CSA/ANSI C800:25, a fire was ignited inside a Quantum3 unit and allowed to burn for over 22 hours. The results demonstrated that the fire was effectively contained within the initiating unit and did not propagate to adjacent units, even in the absence of intervention or water-based suppression measures.
“Active Ignition Mitigation System (AIMS) Testing: Wärtsilä validated its proprietary AIMS technology, which proactively ignites flammable gases at the earliest stages of a thermal event. This pioneering approach prevents uncontrolled deflagrations and maintains full enclosure integrity during extreme simulated conditions.“

What they said:

Dana Parmenter, Commercial Vice President, Industry, CSA Group: “CSA Group was pleased to support Wärtsilä’s fire safety testing program through close collaboration between our North American and Asian teams. The strong coordination between teams helped ensure the testing was carried out smoothly and effectively.”

Mishaal SyedNaveed, Product Manager – Fire Protection at Wärtsilä Energy Storage: “These results reflect years of engineering innovation and safety-first design. By completing all three tests, Quantum3 has proven its best-in-class safety performance, giving our customers and the general public confidence that Wärtsilä systems are ready for the most demanding applications.”

More setup/testing images courtesy of Wärtsilä: