charging port pins

hi,

can anyone tell me what the pins do on the fenix 5 charging port.

assuming this is the top of the watch:

TOP eg 12 o clock

pin  0

pin 0  <------this pin is heavily corroded   is this pin used for charging?

pin 0

pin 0

BOTTOM eg 6 o clock

The watch is out of warranty so cant be returned

any info would be great