Ampace, a provider of advanced lithium-ion energy storage solutions, has presented the results of a large-scale fire test (LSFT) of its PU100 UPS battery system at Data Centre World Asia 2026. During a conference presentation titled “LSFT for UPS Battery System: Last Key Piece toward Ultimate Safety,” Dr. Drew Feng discussed evolving fire safety requirements and shared findings from the company’s testing.
Under the tested conditions, thermal runaway remained confined to the initiating module, with no propagation to adjacent modules or target cabinets. No sprinklers were activated during the test, while the fire self-extinguished after approximately 40 minutes. No re-ignition was observed during the subsequent 24-hour monitoring period.
Assessing Safety Beyond the Initiating Module
For data centre operators, battery fire safety involves both reducing the likelihood of failure and limiting the impact of thermal runaway if an incident occurs. Large-scale fire testing evaluates how a battery event develops and whether it can spread to surrounding equipment under defined installation conditions.
Dr. Feng’s presentation examined installation-level LSFT provisions under the sixth edition of UL 9540A and the importance of evaluating fire propagation, thermal exposure and re-ignition. The presentation also addressed the influence of battery design and installation layout on the outcome of severe fire events.
Testing Under Dense Installation Conditions
Ampace tested the PU100 under a configuration designed to represent dense data centre installations. The test setup featured a 3-metre ceiling height, zero side-by-side cabinet clearance, 20-millimetre back-to-back clearance and 850-millimetre face-to-face clearance. All cabinets were maintained at 100% state of charge.
Heaters were used to initiate thermal runaway in the trigger module, which was subsequently ignited to establish sustained combustion. The test monitored fire development, propagation and sprinkler activation, followed by a re-ignition observation period and post-test teardown analysis.
The results presented by Ampace included:
- No thermal runaway propagation to adjacent modules and no fire spread to target cabinets.
- No sprinkler activation during the test.
- Self-extinguishment after approximately 40 minutes.
- No re-ignition during the following 24 hours.
- No burning debris escaping the cabinet.
- Wall temperature rise below 80°C.
- Ceiling steel beam temperature below 250°C.
According to Ampace’s comparison presented at the conference, the test met the assessed UL 9540A sixth-edition LSFT criteria and demonstrated additional margins on several measures. The company reported wall temperature rise below the cited 97°C limit and ceiling steel beam temperature below the cited 538°C limit. The 24-hour observation period also extended beyond the 12-hour re-ignition period referenced in the presentation, with no sprinkler activation recorded during the test.
Safety Engineered at Module and Cabinet Levels
The PU100 is designed to support dynamic AI workloads and backup power requirements and incorporates multiple layers of protection. These include all-metal module and cabinet enclosures, ceramic thermal insulation, high-voltage boxes and cabinets, and thermal barriers intended to limit fire propagation.
Post-test teardown provided additional findings on containment. Modules adjacent to the initiating module showed no thermal runaway and retained normal voltage readings of 53.2 V. The initiating cabinet showed discoloration but no significant structural damage or collapse, while the adjacent cabinet retained its mechanical integrity and was reported to remain operational.
Dr. Feng has experience in battery safety standards development and has contributed to the development of 19 UL standards, including UL 9540 and UL 9540A, which address energy storage system safety and thermal runaway fire propagation testing. He recently became the first expert from China’s lithium-ion battery industry to receive the UL Standards Outstanding Contribution Award and also received the TC Members Five-Year Honorary Medal.
By presenting the test configuration, measured results and teardown findings, Ampace provided data centre operators and infrastructure partners with information for evaluating UPS battery fire safety. The company is combining large-scale testing with participation in standards development to advance battery systems for backup power applications and thermal runaway containment.
Electrify your feed! Click here to join our Whatsapp group and to get the latest updates, expert insights, and innovations driving India’s energy storage revolution.
