G-Shock MRG-8100B-1A - Manual (Page 11)

10
Before using the watch...
Expose the watch to light.
Your watch runs on electrical power generated from light, which is
stored by a rechargeable battery. Long-term storage of the watch
can cause power to run low, so be sure to expose the watch to light
before using it for the first time. See page 18 for more information.
Low Battery Alert
When battery power is low, the second hand of the watch will jump
at 2-second intervals in the Timekeeping Mode to let you know that
charging is required. See page 20 for more information.


*UMPS
Power Saving
Power Saving causes the watch to enter a sleep state automatically,
which stops movement of the analog hands in order to save power
whenever the watch is left in the dark.
The watch will exit the sleep state if you expose it to light or perform
any button operation.