Description

Using an advanced, patented rate-of-change algorithm, the BES detects battery electrolyte vapour typically released during the initial venting phase, as well as hydrogen and carbon monoxide gases emitted during thermal runaway. The ability to detect this first vent event provides a critical early warning of potential thermal runaway in lithium-ion battery packs.

This proactive early detection enables timely and appropriate corrective actions, significantly reducing the risk of thermal runaway. The BES employs a patented rate-of-change algorithm specifically designed to identify significant variations in the concentration of target gases within a sealed battery pack.

Operating principle

During thermal runaway, various gases are released from the battery cell. In the initial phase, high concentrations of electrolyte vapours escape, including gases such as ethylene carbonate (EC), diethylene carbonate (DEC), ethyl methyl carbonate (EMC) and dimethyl carbonate (DMC).

As the event progresses toward a more critical state, concentrations of hydrogen (H₂) and carbon monoxide (CO) increase significantly.

The BES Series sensor is equipped with a siloxane-resistant metal-oxide semiconductor (MOS) sensing element that is highly sensitive to electrolyte vapours as well as H₂ and CO. Thanks to its sensitivity to multiple target gases, the BES sensor enables reliable and early detection compared with conventional gas sensors.

In addition, the BES sensor incorporates a patented, integrated rate-of-change algorithm that triggers an alarm as soon as a significant increase in any of the monitored gases is detected.