As part of its commitment to achieving the highest level of safety certification, WATTALPS carried out rigorous thermal runaway containment tests on its battery systems in June 2025. These tests were witnessed by Bureau Veritas and were designed to demonstrate that a single-cell failure would not trigger the propagation of thermal runaway throughout the battery.

To conduct the test, WATTALPS initiated a controlled thermal runaway event by causing an internal short circuit in a selected cell. This was done by nailing the cell to provoke uncontrolled self-heating. The procedure was performed on a fully charged battery module that had been preheated to 37°C, with the ambient temperature in the test chamber maintained at approximately 40°C.

During the test, all resulting gases were safely vented through a dedicated safety valve. No fire or explosion occurred at any point, and the thermal runaway was successfully contained to the targeted cells. There was no propagation to other cells within the module or to neighboring modules. The temperature of nearby modules rose by less than 5°C, and the final battery voltage remained above 90% of its initial value.

Visit us at booth #4045 for an exclusive preview of the test results!