UL 9540A Commercial Energy Storage Systems (ESS) Testing
Your Test Plan for Safe Commercial Battery Energy Storage Systems
Ensure your products and systems meet UL 9540A requirements
The use of battery energy storage systems (ESS) in commercial buildings is growing rapidly worldwide. For lithium-ion battery and ESS manufacturers, ensuring the safety of these products and systems is crucial, not just for everyday operation but also under demanding conditions and during catastrophic events. Understanding and mitigating fire hazards, thermal runaway, and other risks associated with energy storage systems helps protect public safety and prevent costly accidents.
UL 9540A is a test method for evaluating the fire safety hazards associated with propagating thermal runaway within battery systems. Thermal runaway happens when a battery cell short circuits and begins to heat up uncontrollably, which can lead to a fire. It’s one of the primary risks related to lithium-ion batteries, which continue to grow in popularity across various industries and applications.
The UL 9540A tests establish that a storage technology is capable of reaching thermal runaway and then assess the technology's fire and explosion hazards.
Benefits of UL 9540A Energy Storage Systems Testing
- Identify and manage potential hazards in energy storage systems
- Ensure regulatory compliance as specified in NFPA 855, UL 9540, the International Fire Code (IFC) and building codes
- Increase safety with comprehensive thermal runaway analysis
- Build stakeholder trust with verified battery performance data
- Enhance brand reputation by adhering to rigorous safety standards
UL 9540A & Thermal Runaway Testing at a Glance
UL 9540A tests determine whether a battery storage technology can reach thermal runaway and then assess the resulting fire and explosion hazards.
Thermal runaway occurs when a chemical reaction spirals out of control and can no longer safely dissipate excess heat. This condition can be triggered by internal short-circuits, overcharging, physical damage to cells, or extreme temperature environments.
The UL 9540A test method is comprised of four levels:
1. Cell-Level Tests
2. Module-Level Tests
3. Unit-Level Tests
4. Installation-Level Tests
If an ESS technology meets the performance criteria at any of the first three levels, further testing is not required. Otherwise, testing continues to the next level.
DEKRA provides Cell-Level Testing, which includes Thermal Runaway Testing,
Gas Characterization Testing and Flammability Testing
.
Process of UL 9540A Cell Level Testing
Cell level tests force an individual battery cell into thermal runaway in a pressure vessel. Generated gasses are collected and analyzed for composition. These gasses are then used for lower flammability limit (LFL) tests, maximum explosion pressure (Pmax) tests, and burning velocity tests.
Inducing Thermal Runaway
The cell is subjected to the specific abuse conditions until it begins to self-heat and decompose. ARC measurements are taken to characterize thermal and kinetic properties. This step is performed within a pressure vessel to contain the process effectively.
What Causes Thermal Runaway?
Thermal runaway in Energy Storage Systems (ESS) occurs due to the failure of individual cells within the system. When these cells experience an internal short circuit, they release a significant amount of energy and flammable gases. The internal short circuit happens when the cell's internal separator is damaged, allowing for a rapid discharge and a sudden increase in heat generation. This cell-level failure can spread, ultimately leading to the failure of the entire ESS. Internal short circuits are most commonly caused by thermal abuse, physical abuse, electrical abuse or manufacturing defect.
How DEKRA Helps with Cell-Level Testing
How is Cell-Level Testing Conducted?
Sectors Requiring Li-ion Battery Safety Testing
A number of critical industries rely on Li-ion Battery Testing to ensure the safety and performance. This testing is crucial for mitigating risks associated with thermal runaway and enhancing overall safety in diverse applications.
| Energy Storage Systems | Electric Vehicles (EV) | Renewable Energy |
| Telecommunications | Grid Ingrastructure | Industrial Applications |
| Medical Devices | Consumer Electronics | Aerospace and Defense |
Your Experienced Partner for UL 9540A ESS Testing
- DEKRA is an ISO 17025 accredited laboratory, demonstrating its compliance with the international standard
- Offering state-of-the-art labs and testing facilities to perform ESS testing worldwide
- A leader in the future of mobility and EV testing
Did you know DEKRA can perform all three required UL 9540A Cell Level Tests?
DEKRA is one of only a few labs in the US certified and equipped to conduct all three UL 9540A cell-level tests, meeting the increasing demand for this critical assessment.
