Thermal runaway detection device and early warning system of battery cluster

The utility model discloses a thermal runaway detection device and an early warning system of a battery cluster, and relates to the technical field of battery safety online monitoring, and the thermal runaway detection device is installed in a battery pack unit. The thermal runaway detection device comprises a shell and a cover body, the shell and the cover body are each provided with a semi-optical cavity, and the two semi-optical cavities form an optical cavity after being closed; the inner space of the shell is divided into a sound detection area, a pressure detection area and a particle detection area by the optical cavity; the sound detection area is provided with a sound sensor; the pressure detection area is provided with a pressure sensor used for monitoring air pressure changes. And the particle detection area is provided with a laser transmitter and a light receiving sensor which are used for monitoring the concentration change of nano particles generated when a battery cell in the battery pack unit