Automatic watches are very intricate pieces of engineering that bring a lot of enjoyment to its wearer.
But wearing an automatic (or manual winding) watch comes with a flood of questions regarding the movement. And rightfully so: you want your watch to operate as long and as accurately as possible.
So here is all you need to know about letting your watch stop, for how long, why you should (sometimes) keep your movement wound and how.
Is it bad to let your automatic watch stop?
It’s not bad to let your automatic watch stop. Automatic watches are perfectly safe when stopped – that is to say that the movement doesn’t run anymore because the mainspring is fully unwound.
Just wind again the next time you want to wear it, and you’re good to go.
When the mainspring is fully unwound, it just can’t power the movement of the watch to run continuously. This is when your power reserve is out. As a result, no more power is sent to the escape wheel, which is the wheel that makes your watch “tick” multiple times per second.
When the escape wheel doesn’t get power anymore, it stops interacting with the pallet fork. In turn, the pallet fork won’t make the balance wheel move back and forth. When the balance wheel stops, the watch stops.
And there is nothing wrong with this.
An automatic watch (or a manual winding watch) doesn’t get damaged when the movement stops. It’s a very normal use case when you don’t wear your watch multiple days in a row and forget (or don’t want) to wind it.
The movement will simply come to a rest, like a car engine running out of gas.
Is it bad to leave automatic watch unwound?
It’s not to leave your automatic watch unwound. You can let your automatic watch unwound for extended periods of time with no damage to the movement.
You can leave your automatic (or manual winding) watch unwound for long periods and not worry about it. Actually, many mechanical watches that you see in display windows at a watch reseller sit there for months on end being unwound. And they are just fine.
The proof is: as soon as you wind it, it will run within seconds, showing no sign of deterioration.
Also, many watch enthusiasts have watch collection of many pieces, making it impossible to wear them all before the power reserve of a particular watch is out at any point in time. So they will keep their watch unwound, just because it’s easier than to wind them every day.
Even better, when a watch is kept unwound and because the movement doesn’t work, there is actually less wear and tear on some important parts of the movement. Namely, the jewels, pallets or hairspring “rest” during that time, spacing apart the time between servings.
Some experts advise winding the watch every month in order to avoid that the oils (that lubricate the parts of the movement) settle. I don’t worry about this and just wear my watches whenever I feel like it.
Whether they stopped 2 hours ago or 2 months ago, it doesn’t matter: they are just fine, relax.
How long can an automatic watch run without being worn?
It depends on your watch movement. When fully wound, most automatic watches can run for 40 to 50 hours. Some high-end models can run for days or even weeks.
Any modern automatic watch with a movement in good working condition can run for at least 38 hours – this is the minimum power reserve that you will find on pretty much every watch out there.
The vast majority of modern automatic watches run for 40 to 50 hours, with the most common power reserve being 48 hours.
Of course, all these values are true only for a movement that is fully wound and then is put to rest without handling. Every time you move your watch, you will wind the mainspring a little, making the power reserve last a little longer.
More and more manufacturers are now powering their watches with new movements that feature a longer-lasting power reserve:
- Tissot, Certina, and Hamilton (all from the Swatch Group) use the Powermatic 80 movement in some of their watches which, as you guessed, runs for 80 hours when fully wound
- Rolex and Tudor use newer movement in some of their latest offerings (namely the GMT Master II or the Black Bay Fifty-Eight) that can run for 70 hours when fully wound
These movements allow you to take your “business” watch off your wrist on Friday evening and put it back on on Monday morning, and it will still be running and be on time. No setting the time before that “first thing Monday morning, important business meeting”. You know that kind of meeting, right? You don’t want to be late because of your watch, do you?
Now, some high-end models have crazy long power reserves.
The Lange 31, from A. Lange & Söhne, can run for 31 days (yes, thirty one days!) before stopping. And it features “a patented constant-force escapement that continuously delivers uniform torque”. So that you can not wear this watch for a whole month, and it will still be good to go when fully wound (manually).
Funnily enough, this is watch is not complicated at all, featuring only a date complication. As such, it really doesn’t need a power reserve that long… but keeping perfect time all the time is not the only reason to wear a watch, right?
Is it better to keep an automatic watch wound?
Keeping your automatic (or manual winding) watch wound is better for accuracy. And it’s more practical if your watch has many complications that you have to set every time it stops.
When the mainspring is fully wound, this is when the most torque is applied to the whole movement of the watch. As a result, the watch operates more accurately.
This is why some high end model have a special mechanism that prevents the mainspring to fully unwind.
For exemple, the IWC Big Pilot Top Gun (Amazon link) has a power reserve indicator showing up to 7 days of power. But the movement inside the watch has actually a 8 day power reserve. But it will stop on the 7th day in order to avoid any accuracy inconsistency that most watches experience when at the power reserve is at its “end of life”.
Now, if you have a very complicated watch, you might want to keep it wound for practical reasons.
A complicated watch is a watch with complications – meaning, any watch that displays anything more than hours, minutes and seconds. As such, many watches are complicated in the sense that they feature also the date, the date or a third time zone. I’m not talking about these watches because they are pretty quick and easy to set up when the movement is stopped.
I’m talking of watches that are more complicated and feature something like an annual calendar, a perpetual calendar, a moon phase indicator. These take a lot more time to set just by the sheer number of steps you have to make to get all the indicators back to their current value.
In this case, it’s better to keep your watch wound just to not go through the hassle of setting up those complications every time you want to wear the watch with a stopped movement.
Not to mention that sometimes, you need to use tools to operate small pushers that sit flush against the watch case. Or that you have to take care that you’re setting your watch “at the right time” in order not to damage the gears and levers in the movement.
In that case, it’s just way easier to keep your complicated watch wound. It can take a few minutes to set up a watch like this, and this might be the difference between enjoying your (wound) complicated watch or reach for that grab-and-go solar powered watch.
So, the question arises:
How to keep an automatic watch wound when you’re not wearing it?
The easiest way to keep an automatic watch wound is to put it in an automatic watch winder. If your watch features a hand winding movement, you can keep it wound by winding it by hand every day.
But you might not have an automatic watch with a hand winding movement. Notable examples feature the Seiko SKX007 or SKX013 (read my full review of the Seiko SKX013)or many watches from the Seiko 5. You have to shake them to start them or wind them, which is not super practical. In that case, what do you do?
Also, you might be gone for a few days and want your complicated watch to wait for you at home, perfectly set up. In those cases, you can’t hand wind your watch. This is when an automatic watch winder comes in handy.
An automatic watch winder is a device that will house your automatic watch and make it spin following a pattern. Spinning your automatic watch will in turn make the rotor spin, activating the automatic winding mechanism of your watch.
This super useful item will keep your automatic watch wound when you are not around. Check the automatic watch winder that I recommend (it’s small, stylish, and relatively silent).
Your watch movement is safe, whether it stopped a few hours ago, or a few weeks ago. And you can keep your watch wound if you don’t want to set it up every time you wear it… but you don’t have to.
Worried about over-winding your watch? I got you covered. Check out my article about over-winding a watch!