Mechanical watches and power reserve

Mechanical watches do not need electricity

Mechanical wristwatches are driven by a mainspring in the movement. This spring can be tensioned both by movement in automatic watches and by turning the crown in hand-wound watches. The energy stored in this way moves the hands on the dial via the wheels.

In automatic watches, a so-called rotor on the underside winds the movement. This can rotate freely and has a weight on one side so that it swings back and forth with the movement on the wrist and tensions the mainspring. Regular wearing of the watch constantly retensions the mainspring and ensures that the movement is constantly driven.

In hand-wound watches, the spring is tensioned by turning the crown. This is also possible with automatic watches, but is not necessary.

The so-called power reserve of a watch determines how long the mainspring can drive the movement without winding. High-quality mechanical Junkers watches store up to 40 hours, i.e. have a power reserve of almost two days.

The power reserve display on the dial of our watches shows how much range in hours the movement still has before it needs to be wound or worn again.