Abstract: A battery cell, a battery module, a battery pack, an energy storage system, and an electric vehicle. The battery cell includes one or more stress sensors. The stress sensors are located on the explosion-proof valve and face outside a housing of the battery cell, or the stress sensors are located on the explosion-proof valve and face inside a housing of the battery cell. Each stress sensor is configured to detect stress that is inside the battery cell and that acts on a corresponding position on the explosion-proof valve, and the one or more stress sensors are configured to transmit all obtained electrical signals to processor. The processor determines a faulty target battery cell based on one or more received electrical signals.

Abstract: A battery safety monitoring system includes a central controller, a fault detection sensor, a flame detection apparatus, and a fire extinguishing apparatus. The fault detection sensor is configured to detect a fault in a target battery module and send fault information to the central controller. The central controller is configured to control the flame detection apparatus to perform flame detection on the target battery module based on the fault information. The flame detection apparatus is configured to send, when detecting a fire in the target battery module, fire information to the central controller. The central controller is further configured to control the fire extinguishing apparatus to start a fire extinguishing operation for the target battery module. There is no need to deploy excessive sensors. Instead, the flame detection apparatus is controlled to perform flame monitoring on the target battery module, to implement low-cost and accurate battery safety monitoring.