Since the end of July 2022, I have been delivering ELKA watches with automatic movements, manufactured by La Joux Perret with 68 hours of power reserve (in general other automatic movements have about 40 hours of power reserve).
The watches work perfectly if worn continuously, even if you leave them for 3 days on your bedside table! However, after the 3 days, the automatic movement stops and has to be wound manually.
What needs to be done is to turn the crown clockwise about 20 turns.
There are mechanical watches on which you have to wind the mechanism every day religiously, but for Elka watches (and many others), they work with a mechanical mechanism, which have an additional module called "oscillating weight". This oscillating weight allows automatic winding without intervention thanks to the movement of the wearer's arm.
The movements of the arm create energy that charges a barrel spring trapped in a barrel, which in turn gives back the energy necessary to operate the watch.
Automatic watches do not require batteries and are therefore powered by "renewable" energy generated by the wearer. Although it is not necessary to wind your automatic watch every day, it is advisable to wind it manually from time to time to ensure its accuracy and prolong its life.
The running specifications of the La Joux Perret G100 movement leave the factory with a maximum deviation of 30 seconds/day when checked on 3 positions - with an isochronism of +/- 20 seconds per day.
(A regulating organ oscillating in a perfectly regular way is qualified as isochronous)
Your watch needs your movements!
The automatic watch is equipped with an oscillating weight or "rotor", this system mounted on a ball bearing will rotate with each of your movements which will create the energy necessary for the movement - (like a dynamo). If the watch is not worn regularly or frequently enough, the energy stored in the barrel spring is depleted. It is therefore important to move your arm regularly when you wear it to keep the "rotor" moving and thus recharge the watch.
In the case of less active people, it will be necessary to wind the watch more frequently.
But avoid wearing the watch during sports activities such as golf, tennis, squash or basketball (...) which could disturb the winding mechanism.