Patent ID: 8277965

Claim:
A battery pack thermal management system, comprising: a battery pack enclosure configured to hold a plurality of batteries, wherein said battery pack enclosure is comprised of a high temperature material; and an enclosure failure port assembly integrated into a wall of said battery pack enclosure, wherein said enclosure failure port assembly remains closed during normal operation of said battery pack, and wherein said enclosure failure port assembly opens during a battery pack thermal runaway event and provides a flow path for exhausting hot gas from within said battery pack enclosure, wherein said enclosure failure port assembly directs said flow path at an angle away from a normal of said wall of said battery pack enclosure, and wherein said enclosure failure port assembly further comprises: a port within said wall of said battery pack enclosure, wherein said flow path through said port; a cover sealed to an exterior surface of said wall of said battery pack enclosure, wherein said cover covers said port and is sealed to said wall along a juncture formed between a cover perimeter and said exterior surface of said wall; a first sealant, wherein said first sealant seals a first portion of said juncture of said cover perimeter and said wall, wherein said first sealant has a first melting temperature; and a second sealant, wherein said second sealant seals a second portion of said juncture of said cover perimeter and said wall, wherein said second sealant has a second melting temperature, wherein said second melting temperature is higher than said first melting temperature, wherein said first and second melting temperatures are lower than a melting temperature corresponding to either said battery pack enclosure or said cover, and wherein said first sealant fails during said battery pack thermal runaway event before said second sealant fails and wherein said first portion of said juncture opens before said second portion of said juncture during said battery pack thermal runaway event.