BATTERY PACK THERMAL RUNAWAY (TR) PROPAGATION MITIGATION SYSTEM

A thermal runaway (TR) propagation mitigation system includes a plurality of battery modules, and an onboard recirculation system coupled to the plurality of battery modules. The onboard recirculation system includes a primary valve for transitioning the onboard recirculation system between a closed loop configuration and an open loop configuration, a cooling fluid container storing cooling fluid provided to the TR propagation mitigation system when the onboard recirculation system is in the closed loop configuration, and a pump for flowing the cooling fluid through the TR propagation mitigation system when the onboard recirculation system is in the closed loop configuration. A method of cooling a plurality of battery modules includes transitioning a primary valve between an open configuration and a closed configuration, distributing cooling fluid through a common fluid line to the plurality of battery modules in a battery pack when the primary valve is in the closed configuration.