Thermally Disconnecting High Power Busbars For Battery System Propagation Control

A battery system is described with methods and systems for thermally isolating a battery module experiencing thermal runaway. In one embodiment, a thermal actuator can cut a busbar coupling neighboring battery modules together, thereby preventing or slowing the spread of thermal runaway. In other embodiments, a fusible material can joint portions of a busbar. High temperatures can cause the fusible material to melt off of the busbar portions and thereby break the thermal or electrical conductivity between busbar portions and neighboring modules.