Adee Kaye Men's 35 Jewels Automatic Open Heart Tourbillon Power Reserve Watch Model AK-1097

One of the most useful features that a mechanical watch can have is a power reserve indicator. It's critical that a watch has at least 30% of its mainspring wound for the watch to run at a regular rate. Many watch enthusiasts just pick up their watch from the dresser and shake it a few times, thinking that the watch will run up to standards with this "jump start". An automatic watch must be worn in motion for about 10 to 15 hours per day to give the watch a full wind. Many people wrongfully think that a watch has stopped during the night due to a malfunction, when really the watch never was worn long enough to assure a 24 hour continuous running. The power reserve indicator is like fuel gauge, it shows the wearer how much energy the mainspring is holding. By glancing at this indicator, the wearer can determine if he or she needs to manually wind the watch to give it more power, wear the watch longer, or check for malfunction of the automatic winding. Or, the owner can simply be assured that the available power is adequate. With a manual wind watch, the wearer should fully wind the watch each day, until it stops winding. This guarantees the owner that the watch has roughly 36 or more hours of continuous running. In an automatic watch, the power reserve shows you when the watch is fully wound. This cannot be determined by the feel of the crown; the mainspring and thus the crown "slips" at full wind. In the above picture the power reserve indicator shows the wearer that the watch has about 45 hours of continuous running before it stops.