POWER RESERVE INDICATOR

Power Reserve Indicator

A mechanical watch contains only a certain amount of power reserve to power the functions of the watch before it stops. A fully wound automatic watch usually possesses between 36 and 42 hours of energy before it needs to be wound again; certain automatic timepieces possess a power reserve of up to ten days. A manual wind watch can have a reserve between 48 hours all the way up to 15 days! The power reserve indicator lets the wearer know how much energy the watch still has in the mainspring and the amount of time the movement can continue to run without requiring winding.