Press release — content provided by Besscare · 2026-09-10 · ESS News
Lead
The FLEX 261 Series, including FLEX 261, FLEX 261 AIO and FLEX 261 AIO-3S, completed a Large-Scale Fire Test (LSFT) under CSA C800 and UL 9540A standards, with results showing no flame propagation to target BESS units.
Main Text
POWEROAD’s FLEX 261 Series has successfully passed a formal Large-Scale Fire Test (LSFT) conducted in accordance with CSA/ANSI C800:2025 and ANSI/CAN/UL 9540A:2026 Sixth Edition.
The FLEX 261 Series, including FLEX 261, FLEX 261 AIO and FLEX 261 AIO-3S, was evaluated under a large-scale fire scenario designed to assess system-level fire behavior and the potential for fire propagation between battery energy storage system (BESS) units.
The test was conducted under demanding conditions to evaluate the system’s response in a severe fire scenario. Five BESS cabinets were arrangedto simulate a multi-unit installation, with all battery packs were charged to 100% state of charge (SOC) before testing. Active fire protection systems were disabled during the test, and the cabinet door was left open to compromise the physical containment boundary and further challenge the system’s ability to prevent fire propagation.
Preliminary test results indicate that:
Critical temperatures remained within the required limits.
No flame propagation reached the target BESS units.
These results demonstrate the FLEX 261 Series’ ability to contain a severe fire event and prevent propagation to adjacent units under the tested conditions. The evaluation focused not only on the initiating unit, but also on the potential impact on surrounding BESS units during a large-scale fire event.
Unlike cell- or module-level evaluations, large-scale fire testing assesses the complete BESS in a realistic multi-unit installation, verifying how system design, thermal management and enclosure protection work together to prevent a single-unit fire from escalating into a multi-unit event.
The FLEX 261 Series is designed for commercial and industrial energy storage applications, offering three configurations: FLEX 261 (a battery-only system), FLEX 261 AIO (an all-in-one ESS), and FLEX 261 AIO-3S (a 3S-integrated ESS with in-house BMS, PCS and PMS/EMS). Across the series,multiple safety features are integrated into battery management, thermal management, electrical protection and system architecture. The LSFT represents an additional validation step in evaluating the performance of these integrated safety measures under extreme conditions.
For POWEROAD, the completion of the LSFT reflects its continued focus on advancing system-level safety and supporting the reliable deployment of battery energy storage systems. Through engineering development and rigorous testing, the company continues to strengthen its approach to safer energy storage solutions.
Disclaimer: This article is published as a press release. The content has been provided by Besscare and has not been independently verified by Besscare. Besscare does not endorse any specific product, company or technology referenced herein.
