Siemens Dual-Wavelength Detection Technology Can Identify Smoldering Li-ion Battery Energy Storage Systems Earlier

Florham Park, N.J.  | October 7, 2021

  • Detects smoldering or off-gas particles unique to li-ion batteries up to five times faster than competition
  • Results in enhanced ability to prevent thermal runaway
  • Designed to easily integrate into Siemens or existing facility fire alarm systems
  • Ideal for facilities, applications, and processes at higher risk in case of fire


As demand and installations of lithium-ion (li-ion) battery energy storage systems increase, fire protection and detection systems are critical for both safety and financial reasons. Very early warning fire detection is key to preventing catastrophic fire events. Siemens FDA241 aspirating smoke detector utilizes two sensing wavelengths to differentiate between smoke and deceptive phenomena, enabling increased detection reliability even in challenging environments.


Li-ion battery energy storage systems are used to store and provide energy generated by wind, solar and other renewable energy means. They are also frequently used as backup power or load balancing in buildings. As li-ion batteries age or get damaged they can experience internal faults which can cause overheating of the battery enclosure. If left undetected and not addressed quickly by shut off, disconnection, or e-stop, this condition can lead to thermal runaway – or massive overheating that can result in fire or explosion.  


Siemens’s FDA241 detector can detect smoldering or off-gas particles up to five times earlier than competitive spot detectors, decreasing the risk of thermal runaway in a li-ion battery energy storage system. The patented dual-wavelength technology uses blue and red wavelengths to detect small off-gas particles that are produced in the early stages of battery failure and overheating. Using two wavelengths allows the detector to differentiate dust and steam particles from smoke and off-gas particles, thus signaling the appropriate warning signal and minimizing potential false alarms.


“Once a li-ion battery thermal runaway occurs, it is difficult to put out and can be catastrophic,” says Brian O’Mahoney, UL Fire Safety Segment Head, Siemens Smart Infrastructure USA. “Implementing innovative detection technology can help protect organizations’ assets, keep facility occupants safe, and prevent millions of dollars in potential losses.”


The FDA241 has a VdS approval (no. S 619002) and performance verification as an early warning detection device for li-ion battery off-gas detection. This VdS approval can be used to meet NFPA 855 requirements through equivalency allowance in NFPA 72 section 1.5. Currently there are no other global product performance standards for the detection of li-ion battery off-gas detection.


The FDA241 li-ion off-gas detector from Siemens is available through Siemens Branch Offices and Siemens Solution Partners. To learn more about the detector, please visit

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About Siemens

Siemens Smart Infrastructure (SI) is shaping the market for intelligent, adaptive infrastructure for today and the future. It addresses the pressing challenges of urbanization and climate change by connecting energy systems, buildings and industries. SI provides customers with a comprehensive end-to-end portfolio from a single source – with products, systems, solutions and services from the point of power generation all the way to consumption. With an increasingly digitalized ecosystem, it helps customers thrive and communities progress while contributing toward protecting the planet. SI creates environments that care. With around 70,000 employees worldwide, Siemens Smart Infrastructure has its global headquarters in Zug, Switzerland, and its U.S. corporate headquarters in Peachtree Corners, Georgia, USA.


Siemens Corporation is a U.S. subsidiary of Siemens AG, a global technology powerhouse that has stood for engineering excellence, innovation, quality, reliability and internationality for more than 170 years. Active around the world, the company focuses on intelligent infrastructure for buildings and distributed energy systems and on automation and digitalization in the process and manufacturing industries. Siemens brings together the digital and physical worlds to benefit customers and society. Through Mobility, a leading supplier of intelligent mobility solutions for rail and road transport, Siemens is helping to shape the world market for passenger and freight services. Via its majority stake in the publicly listed company Siemens Healthineers, Siemens is also a world-leading supplier of medical technology and digital health services. In addition, Siemens holds a minority stake in Siemens Energy, a global leader in the transmission and generation of electrical power that has been listed on the stock exchange since September 28, 2020. In fiscal 2020, Siemens Group USA generated revenue of $17 billion and employs approximately 40,000 people serving customers in all 50 states and Puerto Rico.