Garmin G1 Descent is non-responsive to anything

I had no plugged my watch in for 6 months. 

I have it plugged in for 12 hours now and it is still showing the same things:   a picture of a dead battery, and a black triangle.

I try to factory reset, soft, doesn't matter  .....  I hold the LIGHT button down for 60 seconds and nothing happens.

Any ideas what steps to take next....

Thank you!!!