Abuse testing and failure recreation of thermal runaway in lithium-ion battery packs within Exponent’s London laboratory has shown how battery fires initiate and propagate. Here we demonstrate how even small amounts of moisture ingress to sensitive electronic components of the battery pack, such as the battery protection circuitry, can lead to thermal runaway of the cells within the pack. We investigated specific conditions and behaviors of saltwater ingress-driven circuit board faults, and demonstrated localized temperature increases of >100 °C even at relatively low fault currents (mA’s), showing the potential for circuit board faults to propagate to cell thermal runaway. We also explored the extent and severity of e-mobility battery fires resulting from a single cell thermal runaway failure and evaluated various suppression techniques a user may attempt to implement if they experience a battery fire at home. We tested a household water hose as well as different fire blankets deployed both before the forced thermal runaway event and after initiation. The water hose was unable to supply a sufficient amount of water to extinguish the thermal event, however, the average pack temperature was decreased, and the cell-to-cell propagation rate was slowed. Neither fire blanket tested was able to contain the flames or debris ejected from the battery packs and both acted to hold in the heat from the event, increasing the temperature, rather than allow it to dissipate. In addition, we also demonstrated how various design approaches, such as added thermal insulation between cells, can help prevent cell-to-cell propagation and reduce the severity of a battery pack failure.