Ampace Presents Large‑Scale Fire Test Results for PU100 UPS Battery System

Ampace, a provider of advanced lithium‑ion energy storage solutions, disclosed the outcomes of a large‑scale fire test (LSFT) on its PU100 UPS battery system during a conference titled “LSFT for UPS Battery System: Last Key Piece toward Ultimate Safety” at Data Centre World Asia 2026. The presentation was delivered by Dr. Drew Feng, who examined evolving fire‑safety requirements and detailed the test methodology and findings.

Test Configuration and Conditions

The LSFT was conducted under dense data‑centre installation conditions that replicated a typical high‑density layout: a 3‑metre ceiling height, zero side‑by‑side cabinet clearance, 20 mm back‑to‑back clearance, and 850 mm face‑to‑face clearance. All cabinets were charged to 100 % state of charge. Thermal runaway was initiated in a single “trigger” module using external heaters, after which the module was ignited to sustain combustion. The test monitored fire development, propagation, sprinkler activation, and subsequent re‑ignition over a 24‑hour observation period, followed by a teardown analysis.

Key Results

  • No thermal‑runaway propagation to adjacent modules and no fire spread to target cabinets.
  • No sprinkler activation occurred throughout the test.
  • The fire self‑extinguished after approximately 40 minutes, with no re‑ignition observed during the subsequent 24‑hour observation (exceeding the 12‑hour re‑ignition window referenced in UL guidance).
  • No burning debris escaped the cabinet.
  • Wall temperature rise remained below 80 °C, well under the UL‑cited limit of 97 °C.
  • Ceiling steel‑beam temperature stayed below 250 °C, far beneath the UL‑cited limit of 538 °C.
  • Post‑test teardown showed adjacent modules retained normal voltage readings of 53.2 V, indicating no thermal runaway.
  • The initiating cabinet exhibited discoloration but no significant structural damage or collapse; the adjacent cabinet retained mechanical integrity and was reported to remain operational.

UL Standards Compliance

Ampace’s comparison presented at the conference indicated that the test met the UL 9540A sixth‑edition LSFT criteria and demonstrated additional safety margins on several measures, notably the lower wall and ceiling temperature rises. The 24‑hour observation period extended beyond the 12‑hour re‑ignition benchmark, reinforcing the test’s robustness.

Safety Engineering Features

The PU100 system incorporates multiple layers of protection, including all‑metal module and cabinet enclosures, ceramic thermal insulation within modules, high‑voltage box and cabinet barriers, and thermal barriers designed to limit fire propagation. These design elements contributed to the containment observed during the test.

Presenter Credentials

Dr. Drew Feng, who led the presentation, is the first expert from China’s lithium‑ion battery industry to receive the UL Standards Outstanding Contribution Award and the TC Members Five‑Year Honorary Medal. He serves as a voting member of UL technical committees and has contributed to the development of 19 UL standards, including UL 9540 and UL 9540A, which are directly relevant to energy‑storage system safety and thermal‑runaway fire‑propagation testing.

Purpose and Outlook

By sharing the test configuration, measured results, and teardown findings, Ampace aims to provide data‑centre operators and infrastructure partners with a clearer basis for evaluating UPS battery fire safety. The company emphasizes that combining practical testing with active participation in standards development advances battery systems that deliver reliable backup power while limiting the impact of thermal runaway.