#propagation

Battery module propagation test in a dark laboratory — eight large prismatic lithium-ion cells stand clamped on a scorched steel table with thin white barrier sheets between them, the third cell vents a long jet of white-hot gas and sparks sideways while its neighbour glows dull red, grey vent gas rolls across the back wall, dozens of thermocouple wires run from the cells to an instrumentation rack showing live temperature traces, and two technicians in orange fire-resistant coveralls and hard hats watch from behind a scratched blast shield

🔋 Battery Fire Safety August 21, 2026 · 19 min read

Thermal Runaway Propagation: How One Cell Takes a Pack

Thermal runaway propagation turns one failed cell into a lost pack. Here comes the heat budget that decides it, and the design that stops it.