[Newsletter No. 118] [Fire Prevention] ESS Thermal Runaway: 'Off-Gas' Detection is the Golden Time
Hello, this is Radionode.
With the advancement of battery technology, Energy Storage Systems (ESS) are establishing themselves as core infrastructure in various industrial fields. Consequently, the importance of management technologies for battery safety and accident prevention is also growing.
In particular, technology that prevents fires caused by thermal runaway by detecting early signs of battery abnormalities has recently been attracting attention. 'ESS Off-Gas Detection,' which detects gases generated inside the battery, is a key technology for detecting accidents in advance.
In this newsletter, we introduce the concept and importance of ESS off-gas, as well as Radionode's smart gas detection technology for safer battery operation.
What is 'Off-Gas,' the Warning Sign of Thermal Runaway?
Warning Signs from the Battery Before Thermal Runaway
Most large-scale ESS fires originate in a single lithium-ion battery cell. Thermal runaway occurring within the cell transmits thermal shock to adjacent cells, spreading to the module level and eventually to the rack level, leading to a major fire accident. In particular, since suppression becomes extremely difficult once the fire spreads beyond the cell level to the module level, It is of utMost importance to detect abnormal signs early before a heat runaway begins.
Then, how can you check for signs of a battery malfunction? It is precisely 'Off-Gas'no see.
When a lithium-ion battery operates beyond its electrical and thermal permissible limits, the internal temperature rises and electrolyte vapor is generated. Subsequently, once a certain temperature is exceeded, electrolyte decomposition begins, and the internal pressure of the cell increases rapidly. When the limit pressure is reached, electrolyte vapor and a small amount of decomposition gas are released to the outside through the weakly bonded parts of the cell; this is 'Off-GasIt is called '
The beginning of fire prevention is off-gas detection.
Causing fires and explosions, and even significant casualties Thermal RunawayThis is a phenomenon where heat is generated self-amplifyingly within the battery and becomes uncontrollable. If abnormalities such as overcharging, overheating, or internal short circuits occur inside the battery, internal cell pressure increases, and the electrolyte vaporizes and decomposes, releasing off-gas. This off-gas is an early warning sign that appears before flames or smoke, and it poses a high risk of explosion as it contains flammable and toxic gases such as hydrogen and carbon monoxide.
Conventional firefighting methods have been centered on a 'reaction' approach, responding only after smoke, high heat, or explosive gases have already occurred. However, since thermal runaway is already in progress at this point, it is difficult to prevent the runaway itself, even if damage can be minimized. Therefore, early detection of off-gases that appear before thermal runaway is key to ESS safety.
There is a golden time of several minutes to tens of minutes between the occurrence of off-gas, which is the primary venting state, and the onset of secondary venting (thermal runaway). If initial responses such as stopping the ESS, cutting off charging and discharging, cooling, and ventilation are performed during this time, the stress applied to the battery can be reduced, the progression of thermal runaway can be suppressed, and the risk of fire and explosion can be lowered.
Radionode RN171 + UA58-LEL Gas Detection Solution
An ESS safety solution capable of gas analysis, going beyond off-gas detection
Off-gas detection is the first step in preventing ESS fires. However, in actual field operations, beyond simply detecting abnormal signs, Identifying and quantifying in real-time what type of gas is being generated and in what quantitiesThis is the key to preventing the spread of the fire.
If existing off-gas detection systems were limited to acting as signalmen that sounded an alarm by merely detecting the presence or absence (On/Off) of specific electrolyte solvent vapor, Radionode RN171 + UA58-LEL PackageIt identifies the type of gas and even the precise explosion risk levelMachine learning-based smart solutions'no see.
We introduce the four unrivaled differentiating features of the UA58-LEL package that go beyond existing methods.
✔️[Differentiation 1] Composite Measurement of 18 Flammable Gases and Quantification of LEL% : Unlike conventional sensors that capture only electrolyte vapor, the vapor ejected during thermal runaway Combined measurement of 18 types of flammable gases...does not simply detect. Precisely quantified by LEL% (Lower Explosive Limit) valueTherefore, it visually displays the real-time risk level.
✔️ [Differentiation 2] Machine learning-based gas classification Unlike the dual-sensor method that compares with external reference air, the single sensor equipped with Machine learning algorithms quickly detect electrolyte fumes (DMC/EMC) that primarily occur during initial battery overheating.
✔️ [Differentiation 3] Simultaneous temperature and humidity monitoring Breaking the limitations of the existing system that only monitored gas concentration indicators, inside the battery room Simultaneous measurement of temperature and humidity with a single sensor package합니다.
✔️ [Differentiation 4] Excellent scalability and cost-effectiveness without the need for a separate controller Unlike the existing method, which required the essential setup of expensive dedicated control boxes and control systems, without a separate controller natively supports the Modbus protocolIt connects directly to existing ESS facilities (PMS/EMS). It supports PoE and Wi-Fi communication, allowing for economical installation without large-scale construction.
Proven sensor technology, the beginning of a safe industrial site
ESS fire prevention through 18 years of accumulated IoT technology and extensive field experience
As the importance of ESS grows, establishing systems to prevent thermal runaway accidents and detect hazardous gases early is also becoming crucial. To achieve this, highly reliable technology is required to accurately detect early signs of abnormality and respond rapidly.
Based on IoT technology accumulated over more than 18 years across various industrial sites, Radionode has been providing integrated solutions for sensors, wired and wireless communication, and Cloud Serivce monitoring. As a domestic manufacturing-based IoT specialist, we will create a safer and more efficient industrial environment through our proven technology and extensive field experience.
ESHRE 2026 - Life-saving 24-hour temperature monitoring
Radionode will participate in 'ESHRE 2026', Europe's largest reproductive medicine conference, held at ExCel London, UK, from July 5 (Sun) to 8 (Tue), 2026.
Real-time monitoring is essential for the safe storage and quality maintenance of blood samples and reagents. Radionode plans to introduce a life science-specific monitoring solution capable of real-time monitoring of temperature changes, door openings, power outages, and more.
Radionode's differentiating features
✔️ Precise temperature monitoring for blood sample and reagent storage
✔️ CO₂ Concentration and Temperature Monitoring for Dry Incubators
✔️ Cryogenic temperature monitoring for LN2 (Liquid Nitrogen) tanks
✔️ Monitoring of hazardous gases such as EO, O₂, VOC, and PM
✔️ Contact-linked alarm and integrated monitoring system
Experience Radionode's IVF-specialized monitoring solutions firsthand at ESHRE2026.
International Safety and Health Exhibition 2026 - Technology for Creating a Safe Workplace
Radionode will participate in the 'International Safety and Health Exhibition 2026' held at KINTEX Exhibition Center 2 from Monday, July 6 to Thursday, July 9, 2026.
Radionode introduces various hazardous environment monitoring solutions for workplace safety and efficient facility operation at Korea's largest specialized exhibition for industrial safety and health.
Radionode's unique solution
✅ Hazardous gas monitoring
✅ Fire and Explosion Detection Solution
✅ Real-time wind chill monitoring
✅ Noise and Indoor Air Quality Monitoring
The start of building a safe working environment. Experience Radionode's smart solutions at the exhibition.
▶️ Apply for a Pre-visit to the International Safety and Health Exhibition
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