Help Identifying Weird Electronic Component


Attached you find photos of a Li-Ion battery's PCB. I'd like to know what this component is called and what its use is.

The component in question is the three pin stretched silver "bridge". The white blobs seem to be glue, while the black things you see are ICs. There is nothing beneath the brownish center of the component.

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Best Answer

This looks like a resettable PPTC fuse with an additional control terminal. The third terminal is used for external activation: when abnormal conditions like overcharge or overheat are detected by the battery controller, it can force the fuse to open even if the current stays within limits:

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The component sits on the glue blob rather than the PCB because it needs to stay hot when latched up. PCB would act as a heatsink and could reset the fuse before the short circuit is removed.