Batteries are widely used in industry, logistics, buildings and energy production. Charging areas for forklifts and other battery-powered machinery, battery rooms, backup power systems and battery energy storage systems are examples of applications where the safe use and charging of batteries are an important part of risk management.
Battery charging, overheating and fault conditions can result in the release of gases and vapours. The risks and gases that need to be monitored depend on the battery type, battery chemistry and operating environment. Gas detection can be used to detect hazardous or abnormal gas concentrations and enable action to be taken as early as possible.
Different battery types involve different gas risks
Traditional lead-acid batteries are still widely used in applications such as forklifts, industrial machinery and backup power systems. Hydrogen (H₂) can be generated during charging.
Hydrogen is a colourless, odourless and highly flammable gas. Its lower explosive limit in air is approximately 4% by volume. In enclosed or poorly ventilated spaces, the accumulation of hydrogen can create a fire and explosion hazard. Continuous hydrogen detection makes it possible to monitor gas concentrations and detect abnormal conditions.
Lithium-ion batteries involve different gas risks. If a battery is damaged, overheats or experiences another fault condition, it may release gases and vapours including carbon monoxide (CO), carbon dioxide (CO₂), hydrogen (H₂), hydrocarbons, various volatile organic compounds (VOCs) and electrolyte vapours.
The composition and quantity of gases released depend on factors such as battery chemistry, state of charge and the stage of battery failure. For this reason, the gases to be monitored and the appropriate sensor technology should be determined for each application individually.
Gas detection can help identify a developing battery fault
One of the most serious failure scenarios associated with lithium-ion batteries is thermal runaway. During thermal runaway, the internal temperature of the battery begins to rise uncontrollably, potentially resulting in significant gas generation and fire.
Even before thermal runaway occurs, lithium-ion batteries may release electrolyte vapours and other gaseous compounds. Detecting these gases and vapours can provide an indication of a developing abnormal condition and enable earlier intervention.
Gas detection is one part of an overall battery safety system. It complements technologies such as the battery management system (BMS), temperature monitoring, ventilation and fire safety systems.
Where is battery gas detection needed?
The need for gas detection is particularly important in indoor and enclosed environments where released gases can accumulate. Typical applications include:
- forklift and battery-powered machinery charging areas
- industrial battery rooms and charging rooms
- backup power system battery rooms
- data centre battery rooms
- battery testing, maintenance and recycling facilities
- battery energy storage systems (BESS) and energy storage facilities.
When positioning gas detectors, the properties of the target gas, the layout and ventilation of the space, and potential gas release and accumulation points must be considered. Hydrogen, for example, is lighter than air and therefore tends to accumulate in the upper parts of enclosed spaces.
Effective battery gas detection starts with risk assessment
There is no single gas detection solution suitable for every battery application. System design should begin with the battery technology being used, the associated gas risks and the operating environment.
Based on these factors, the gases to be monitored, sensor technology, number and positioning of gas detectors, as well as the required alarms and system integrations, can be determined. Alarm signals can be integrated with ventilation systems, building management systems (BMS), battery management systems or other safety systems.
A properly designed gas detection system supports the safety of battery rooms, charging areas and battery energy storage systems. The objective is to detect abnormal gas concentrations as early as possible and enable action to be taken before the situation develops into a more serious incident.