The First Consensus Standard to Establish Robust Testing Protocols for ESS Reliability and Quality Assurance

The quick adoption of Energy Storage Systems (ESS) has transformed power generation, grid stability, and energy efficiency. However, as ESS installations grow worldwide, making sure of their long-term reliability, safety, and performance under real-world conditions remains a challenge.

While UL 9540A has played a valuable role in battery energy storage system (BESS) fire safety, an additional large-scale fire testing procedure was needed. This need is evident in the upcoming revision of NFPA 855, which will distinguish UL 9540A from large-scale fire testing as two distinct test requirements. To address this gap, CSA Group has published CSA C800-2025, the first consensus standard that establishes a robust testing protocol for ESS reliability and quality assurance programs — including an approved test method for large-scale fire testing. This new standard goes beyond existing safety and performance testing to evaluate ESS durability under extreme environmental conditions, mechanical impacts, other abuse conditions, and large-scale fire testing scenarios.

Why CSA C800-2025 Matters

CSA C800-2025 was developed in response to industry needs, filling a critical gap in the current ESS testing landscape. While UL 9540 focuses on predictable installation conditions, CSA C800 simulates real-world failure scenarios that could cause ESS malfunctions, hazardous failures, and system shutdowns in the field.

This standard provides a structured testing protocol for a representative ESS, verifying its performance and integrity under severe external stress factors such as:

  • Extreme weather conditions (e.g., snow, freezing rain, flooding, and high temperatures)
  • Mechanical impacts (e.g., vehicular collisions and structural impacts)
  • Ballistics exposure (e.g., projectile testing)
  • Large-scale fire events (e.g., thermal runaway and propagation testing)
    With input from regulators, code officials, insurers, manufacturers, and testing experts, CSA C800-2025 is designed to support:
  • Code compliance: Used by Authorities Having Jurisdiction (AHJs) for regulatory assessments.
  • Risk mitigation: Provides insurers and investors with reliable performance data.
  • Market acceptance: Establishes standardized testing protocols recognized across the industry.

How CSA C800-2025 Builds on CSA TS-800:24

CSA C800-2025 expands on the work of CSA TS-800:24, which was a technical specification for large-scale fire testing. CSA C800 is a fully developed, consensus-based national standard, recognized in both the U.S. (ANSI) and Canada (SCC).

Key enhancements include:

  • Integration of large-scale fire testing into a broader ESS testing framework
  • Robust durability testing across various environmental and mechanical conditions
  • A structured methodology to support investment and insurance evaluations

CSA C800-2025 is intended to be a stand-alone document that focuses on an ESS’s reliability and quality assurance, allowing manufacturers to demonstrate their systems’ long-term reliability under extreme conditions.

Global Testing Capabilities for CSA C800-2025

CSA Group’s advanced network of global laboratories support manufacturers in testing their ESS to CSA C800-2025. Our testing facilities in North America and Asia offer:

  • Large-scale fire testing at North Carolina, U.S., and Suzhou, China facilities, with measures in place to align the China laboratory with North American testing standards.
  • Battery electrical, mechanical, and fire testing at our Cleveland, U.S., and Kunshan, China laboratories.
  • Certification for key industry standards including UL 1973, UL 9540, and UL 9540A.

We work closely with Authorities Having Jurisdiction (AHJs) and code officials to align our testing processes with their expectations and regulatory requirements. Additionally, all CSA Group laboratories operate under ISO/IEC 17025 accreditation, an internationally recognized standard that verifies laboratories’ technical competence and ability to produce accurate, reliable test results globally.

About CSA Group

CSA Group is a global organization dedicated to safety, social good, and sustainability. We are a leader in Standards Development and in Testing, Inspection, and Certification around the world, including Canada, the U.S., Europe, and Asia. Our mandate is to hold the future to a higher standard.