Ulysse Nardin

I have a MMD, purchased a few months ago, and have a question about the power reserve dial (I think that is what it's called).  When I wind the watch fully the dial show fully powered (pointing to "up".   If I then wear the watch steady for several days, the power reserve gradually winds down, today I looked at it and it shoed at 1/4, heading to the "down", marker.  My assumption is that normal wear would or should keep the watch fully charged.  Is this incorrect?  Without re-winding it will it eventually need to be rewound manually?  Thanks for any info you can provide. 

... and to sum it up briefly, it depends from the conditions. Generally, the ETA 2892A2 base movement in the Marine series is very efficiently doing its job, and is well winding the mainspring. BUT:

The wearer has to move enough.

This is not meant to offend (some people really do feel offended by that, assuming I suspect them to be lazy couch-potatoes!), but it is a fact: An automatic watch needs a certain category of movements with your arm - like swinging the arm when walking fast, using screwdrivers or other tools, to just name an example. Especially office work on a computer keyboard, or driving a car prevents the rotor from revolving freely enough to reliably wound the mainspring.

If in addition to this, the wearer takes off the watch at night, and uses a multi-function pulse-check digital watch for his sports actiivities, it is clear that the automatic watch will not develop enough energy to supply the movement over a long time. The power reserve display reveals the problem much earlier. The movement's power reserve is good enough to maintain a reasonably accurate time display for a long while, if the mainspring does not get just a tad too less energy to compensate the tension loss caused by the movement. For example: I had stored a watch on a watch winder, which was revolving just a few circles too few to wind the watch completely. Several months passed, before the balance's amplitude collapsed and I realized something is not alright, with the watch being off by several hours. A power reserve hand would have revealed this a lot earlier.

So the first way to achieve a constantly high power reserve would be to make the watch a true companion, also during sportive activities after the office work. In my case, the work necessary to change the car's tires is enough to get my Marine Diver's power reserve from nearly "Down" to "Full" within about forty minutes.

If all this fails, there is the chance of a mechanical problem in the watch's winding system. While this is known to happen, the chance that this is the reason, versus the lack of wearing activity, is about 1:100.

Best regards,
Marcus

for this very thorough and illuminating response.  I am always amazed at the level of knowledge on this forum, as well as the others I am on.  I do have an office job and take it off at night so it is possible that it does not get sufficient movement to maintain the fully powered position.  I guess I should swing my arms around more at work, though I may raise a few questions from my co-workers who may think I am nuts.  Again thanks for the info.

.... maybe you can hit out your competitors? No, to be serious: the better choice would be to do some outdoor sports after work, or buy a dog, which forces you to walk a lot. Your watch - and your physical shape - will thank you.

Kind regards,
Marcus

Hi Marcus,
was wandering how long do think you should leave a watch on a winder whats too long im running mine at approx 3-4 hours per day is this excessive but i also wear all my pieces often thx

... when I used a winder more often than I do now, I had one that made one rotation every minute. this one was active for about ten hours a day, which makes 600 rotations in total. That was enough by far, I assume. On the Orbita website, there used to be a table, indicating the number of revolutions appropriate for various movements. There, the UN Marine Diver is indicated with 650 revolutions per day.

Regards,
Marcus