Walking and hiking really chews up the battery on a GPS watch, especially if you are standing around taking photos! It appears to be more of a time thing. The watch may think you are 'asleep' and go into sleep mode if you stand in one place to long.
The video of the horde of scouts charging was hilarious, as always! :-D
The Garmin yells at you to move if you stand still for too long :) I never stayed in one place for more than 5 minutes.