Most watch enthusiasts will opt for a self-winding watch when looking for a watch. Perhaps most known as an ”automatic” watch, self-winding watches have become the go-to choice fine for luxury watch brands and of course watch enthusiasts due to their complicated mechanism that requires fine watchmaking, expertise, and craftsmanship.
But what is a self-winding watch? That’s exactly what we will look closer at in this article.
How Does a Self-Winding Watch Work?
Self-winding watches are powered by mechanical movements that do not have batteries. Instead, the key features of a self-winding watch are a mainspring and a rotor. The rotor rotates freely when the watch is subject to movements thanks to gravity (primarily when the watch is on the wrist). When the rotor rotates, it winds the mainspring which works as a means of storing energy. This is achieved by putting the center of gravity on one side of the center pivot. The energy is stored in the mainspring and the mainspring then gradually ”unwinds” over time as the watch continues to tick, thus providing energy for the watch to run.
Self-winding watches normally have a power reserve of around 24-48 hours (with some watches having a shorter power reserve and some watches having a longer), and this is the time it will take until the mainspring will be fully unwound and out of energy, thus causing the watch to stop. But the great thing about a self-winding watch is that as long as you wear it, the rotor inside will continue to rotate, thus consistently charging the watch with energy, ensuring that the watch never stops. And the power reserve will ensure that when you’re not wearing it for example overnight, it continues to run when it is time to wear it again.
This is why a longer power reserve in a self-winding watch is something that most watch brands work to improve in order to allow you to leave the watch for some time, for example, if you’re not going to wear it over the weekend, but it is still ticking when it is time to wear it again, thus preventing you from having to set the time.
Depending on how active you are and how much you move your wrist, the time it takes before an automatic watch is fully wound will vary. Those who are not very active may never fully wind the mainspring, but as long as they consistently wear the watch, the movements from the wrist are usually enough to keep the watch running. But those who are active may fully wind their self-winding watch within a matter of a few hours.
When the mainspring in a self-winding watch is fully wound, the movement will ”disconnect” and stop providing energy to the mainspring with the purpose of not overwinding it, which is something that may otherwise eventually cause it to snap. So this is a feature that saves you from accidentally breaking your watch by simply being too active.
Furthermore, most self-winding watches, and essentially all watches that are a bit more expensive also come with a manual-winding function. This means that in addition to the rotor which generates energy to the mainspring through movement, you can also manually wind the watch by rotating the crown, usually clockwise.
There are great practical reasons why self-winding watches also have a manual-winding function, but in general, it is convenient when your watch has stopped and the mainspring is fully unwound. In these cases, it is advised that you manually wind the watch before putting it on. The alternative is to shake the watch a lot to make the rotor rotate, but this can cause unnecessary wear to the movement and is also quite impractical.
Therefore, it is advised that when you are looking for a self-winding watch, you also look for one that has a manual-winding feature. In general, it’s primarily some of the most affordable self-winding watches that don’t have the manual winding function since it is an additional mechanical complication, and neglecting it will allow them to keep the cost down.
What is the difference between self-winding and automatic watches?
The answer is that there is no difference between self-winding and automatic watches - they’re just two different names for the same thing. Self-winding and automatic watches are often confused and many people believe that they are two different things, whilst in fact, they are not.
Automatic means that the watch automatically powers itself via a rotor that generates energy to the mainspring whilst on the wrist and subject to movements. And a self-winding watch just explains the technology behind it, where the rotor winds itself (self-winding), which is the whole concept of an automatic watch.
Does a Self-Winding Watch Need to be Wound?
No, a self-winding watch does not need to be wound, however, it is advised to do so.
As mentioned, not all self-winding watches come with a manual-winding function and so in these cases, you don’t really have an option to wind it. If your self-winding watch that doesn’t have this function stops, your only option is to ”shake” it (carefully) to make the rotor rotate, causing the watch to start.
But if your watch does have a manual-winding function (which most have), it is advised that you always manually wind it to start it again. This is because shaking the watch can cause unnecessary wear and tear to the movement, which can be avoided.
Furthermore, it is also good to manually wind your self-winding watch occasionally, for example, a few times a week. There are several reasons for this. Firstly, even if your watch is self-winding, the movements from your wrist may not be enough to fully wind the watch. Therefore, occasionally winding it is a great way to keep the mainspring wound. And as mentioned about the fact that the rotor cannot overwind the watch, the same goes for essentially all automatic watches when manually-winding it. If the movement is fully wound, it will disconnect and not lead any energy to the movement. But when you feel the resistance is getting greater when rotating the crown, it is an indication that the movement is fully wound and you can stop winding it.
Furthermore, manually winding a self-winding watch can also be good for the health of the movement. It’s important to remember that a self-winding watch is a mechanical piece of engineering and to keep all the parts functioning properly. If you’re not using the manual-winding function, the lubricants of these parts may run dry, so winding it will help you keep the movement healthy and sound for as long as possible.
How long does a self-winding watch last?
It depends! If we are talking about the power reserve of a self-winding watch, it relates to the amount of energy the mainspring can store. Different watches have different power reserves, but most watches have a power reserve of about 24 to 48 hours, although some watches have more and some have less. This is the amount of time that the watch will run when not in use when the mainspring is fully wound.
The other question is how long a self-winding watch will last before it essentially breaks or loses so much accuracy that it cannot be used for timekeeping. How long a self-winding watch lasts depends on a number of different factors, perhaps most importantly the quality and level of craftsmanship of the movement.
The main reason that self-winding movements start to function poorly is that the lubricants run dry, which obviously affects the performance and accuracy of the movement. Just like with all mechanical objects that consist of countless different parts that work together in harmony to create a functioning piece of engineering, a self-winding movement will need occasionally maintenance and servicing. An exception is of course if something in the movement breaks, for example, if you accidentally drop the watch. In this case, components may have broken and need to be repaired.
Rolex, for example, has a recommended service interval of 10 years, but Rolex moments are obviously extremely well-made movements made with utmost precision and craftsmanship. More affordable self-winding movements will need more frequent services in order to maintain their accuracy and performance. A general guideline is that you should have your watch serviced every 2-5 years. Much of what dictates how frequently you need to service your movement is its performance. If your watch keeps perfect time and isn’t losing accuracy, it’s a good sign that it is healthy and sound and doesn’t need to be serviced.
When a self-winding movement is serviced by a watchmaker, it is completely disassembled, cleaned, worn-out or broken parts are replaced, lubricated, and then assembled again.
Does a self-winding watch have a battery?
No, as discussed above, a self-winding watch does not have a battery. Battery-Powered watches (quartz) are powered by batteries, and once the battery runs out of energy, it needs to be replaced. Self-winding watches, on the other hand, are powered via a rotor. As such, an automatic watch can, at least in theory, run forever, as long as it is consistently worn and is able to rotate to generate power to the mainspring.
What is a manual wind watch?
Unlike a self-winding watch, a manual wind watch does not have a rotor. Instead, it gets its energy solely from the fact that you have to consistently wind it manually. So whilst many self-winding watches have both a manual-winding function and a rotor, manual wind watches only have the manual wind function.
Before the self-winding movement was invented, watch brands only used self-winding technology. This is because this was during a time that quartz didn’t exist yet either. The self-winding movement was first invented by the Swiss watchmaker Abraham-Louis Perrelet in the 1770s.
Today, some people still enjoy hand-wound watches due to the connection it gives the wearer with the mechanical movement. It’s simply a nice way to appreciate the fine mechanical craftsmanship that sits inside.
But on the other hand, a lot of people find the hand-wound alternative quite annoying now that they have the self-winding alternative since it means you constantly have to remember to manually wind the watch. Otherwise, it will run out of energy and stop.