Envision’s record 49-hour fire test breaks new ground in energy storage safety

PRESS RELEASE

Shanghai, China, July 4, 2025 – Envision Energy, a global leader in green technology, has successfully completed a groundbreaking large-scale fire test for its smart energy storage system, raising the bar for safety, environmental responsibility, and system resilience. Conducted under full on-site supervision by the Canadian Standards Association (CSA Group), strategic partners, and North American Fire Protection Engineers (FPEs), the test fully complied with the stringent CSA C800 standard – a consensus standard developed with input from insurers, regulators, and industry experts, providing one of the most authoritative international safety benchmarks for energy storage.

World’s Densest BESS Setup: 5cm Tightest Spacing, Zero Fire Propagation in 49 Hours

The test recreated real-world worst-case site conditions by placing four fully charged (100% SOC) 5MWh Envision Smart Energy Storage containers (A, B, C, D) in an ultra-dense back-to-back, side-by-side configuration – just 5 centimeters apart, compared  to the typical industry standard spacing of 3 to 5 meters. This setup represents the most energy-dense fire test layout ever attempted, significantly increasing the challenge due to heightened thermal coupling and limited airflow. Importantly, the burn was allowed to proceed with zero intervention.

The test pushed the boundaries of the most stringent safety limits – yet even under unprecedented thermal stress and energy concentration, the system showed exceptional resilience and containment. Container A burned for 49 hours and 32 minutes, reaching a peak temperature of 1,297°C. Meanwhile, internal battery temperatures in the adjacent containers B, C, and D remained stable at just 35°C, 44°C, and 43°C respectively – well below our normal operational window.

Notably, container A maintained structural integrity throughout the burn, showing no deformation, no collapse, and intact sealing gaskets. Even more impressively, there was zero fire spread or damage to neighboring containers. Units B, C, and D remained unscathed inside and out, with post-test inspections confirming all internal modules were fully operational and undamaged.

3-Hour Ignition Delay –  Extended Window for Fire Response

To simulate a worst-case ignition scenario, the fire was initiated by applying high-power, synchronized heating to four battery cells within a modified pack, from which the nano-level thermal insulation had been removed. The ignition source was strategically placed at the center of the container cluster – where fire spread risk is greatest in all directions. Under these extreme conditions, ignition took nearly three hours – over 50% longer than typical – offering a critical window for early detection and emergency response.

Zero Emission Fire Testing – New Benchmark for Environmental Safety

Environmental safety was also a key focus throughout the test. All combustion gases from the burning container A were captured by overhead smoke hoods, analyzed for composition, and fully neutralized through advanced treatment. The entire 49-hour test produced no odors, no emissions, and zero pollution, setting a new industry benchmark for clean and environmentally responsible fire testing in energy storage.

AI-Driven Safety & Full Lifecycle Asset Protection

Envision’s AI-powered Smart Energy Storage System offers superior safety even under extreme conditions. It integrates Envision’s proprietary high-safety battery cells within a robust three-layer safety architecture spanning cell, pack, and system levels. Coupled with AI-driven fire detection and active pack-level firefighting, the system isolates thermal events within a single container. To date, Envision’s storage systems have been deployed in over 300 projects worldwide with zero safety incidents.

This breakthrough fire test proves that even in highly unlikely fire scenarios, Envision’s Smart Energy Storage can fully contain risk within a single container. The quantifiable safety results provide insurers with greater confidence to underwrite storage assets, paving the way for broader commercial adoption and accelerating the transition to safe, large-scale energy storage.