BST is the Battery Safety Terminal and has a fusible link that has been known to die for reasons other than an accident.

See below photo.

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"When the Team Chief said.... You're trapped in a hole with nothing but a goat and a slinky, what do you do? Stubby said, I'm not sure but it won't end well for the goat...." ~(Overheard) Last day, Phase 3, Q Course