Lithium batteries used in electric vehicles (EVs) may experience internal short circuits due to manufacturing defects or impact damage. A battery with an internal short circuit can heat up rapidly, causing thermal runaway. Thermal runaway in one cell can propagate in a chain reaction to adjacent cells, which is the main cause of whole‑system fires. To prevent such accidents, various international standards have been established. In design verification and certification tests, thermal conduction performance tests based on thermal runaway results are required.

This application note introduces a solution using the HIOKI Data Logger for thermal conduction performance testing to understand the thermal conduction process during battery thermal runaway.