Sunwoda 5MWh Liquid-Cooled Energy Storage System Large-Scale Fire Test Successfully Completed

2026-05-11 | Calvin

As energy storage systems continue to evolve towards larger capacities and higher energy densities, industry attention to safety is shifting from "cell-level safety" to "system-level safety". At the same time, international standards such as UL 9540A and CSA C800 are continuously being updated, driving safety validation in energy storage from standardized testing towards system-level assessments that more closely reflect real-world scenarios.

In this context, Sunwoda conducted a large-scale fire test on its 5MWh liquid-cooled energy storage system, further validating the system-level safety performance and safety boundaries under conditions far more severe than typical application scenarios.

More Stringent Test Conditions
System-Level Validation for Real-World Scenarios

This test was based on extreme risk scenarios that real energy storage projects might encounter, with comprehensive reinforcement of key testing conditions to create a more challenging validation environment.

The test utilized a "1 trigger container + 4 real target containers" arrangement, reducing the spacing between containers to an extreme minimum of 15cm, which is denser than conventional project layouts. All systems were at 100% state-of-charge (SOC), while simulating active fire suppression failure. Pressure relief and ventilation panels were opened, and some key thermal insulation materials were removed to further strengthen thermal runaway propagation conditions.

The overall test process strictly followed the ANSI/CAN/UL 9540A:2026 (6th Edition) and CSA/ANSI C800:2025 international standards, and was executed by the globally recognized certification body CSA, with professional inspection by Atar Fire Fire Protection Engineers (FPE), enhancing the rigor and reference value of the test.

Beyond "Safe from Fire"
More Importantly: "Risk Controllable"

Under these extreme test conditions, the trigger system successfully underwent thermal runaway and sustained combustion, with the overall test lasting over 12 hours. The results demonstrated that the fire was always contained within the trigger system and did not spread to adjacent target systems.

During the test, the adjacent systems remained stable without abnormal propagation risk. After prolonged fire exposure, the main system structure remained intact, further validating the system-level safety protection capabilities of the product under extreme conditions.

Unlike tests that only focus on whether a fire occurs, this test emphasizes whether the system can effectively isolate risks, control propagation, and provide greater safety margins for on-site handling and project operations under extreme conditions.

System-Level Safety Capability
Derived from Multi-Layer Collaborative Design

The system-level safety performance demonstrated in this test results from Sunwoda’s multi-dimensional collaborative design, spanning battery cells, packs, system, and container levels.

At the battery pack level, the product employs multi-layer composite insulation structures and high-performance thermal insulation materials to effectively delay heat transfer from the exterior to the internal cells.

At the system level, the container incorporates thermal break designs and optimized insulation structures to further block heat transfer paths, reducing thermal impact risks between adjacent systems.

Meanwhile, Sunwoda continues to optimize designs around thermal diffusion paths, structural protection, and system collaboration, driving energy storage safety from "single-point protection" towards "system-level collaborative safety."

Validating Safety Boundaries for the Era of Large Capacity

As energy storage systems develop towards larger capacities and higher integration, industry requirements for safety validation are also transitioning from standard tests to system-level assessments that closely reflect real-world operating conditions. Through this fire test under more stringent conditions, Sunwoda further validated the safety boundaries of large-capacity liquid-cooled energy storage systems under extreme conditions, showcasing their system-level safety assurance capabilities.

Looking ahead, Sunwoda will continue to carry out safety validations that more closely reflect actual application scenarios. Leveraging collaborative design from cells to systems, the company aims to continually enhance product safety performance in real operating environments, providing more reliable support for the long-term stable operation of global energy storage projects.