Power Reserve

[skatamail]

My question is specific for the Daytona with the 4130 caliber (newest models) but would generally apply.

The quoted 72hr power reserve is from fully wound. So I would expect my watch to keep time (within Rolex specs) for 72hrs if fully wound and placed on a fixed surface. (I have not tested this)

How much does the power reserve decline when just relying on wearing the watch?

In my experience, I only get 36-48hrs of power reserve when just relying on wearing the watch to keep it wound (10+ days from winding the watch). I probably wear it a few hours at a time on days when I wear the watch, and only wind it if I found it has stopped.

[Adam84]

Can’t speak for the Daytona, but almost no mechanical watch (unless it’s constant force) will be able to keep good time as the mainspring unwinds

[skatamail]

Originally Posted by Adam84

Can’t speak for the Daytona, but almost no mechanical watch (unless it’s constant force) will be able to keep good time as the mainspring unwinds

fair enough... I should have said "keep ticking"

[DJ2020]

Accuracy will start to fade (some more than others) as the main spring becomes unwound. That holds true for all mechanical watches.

[skatamail]

but how long will it keep ticking?

[Tools]

Originally Posted by skatamail

but how long will it keep ticking?

Every automatic watch will eventually wind down to the amount of wind that you put into it each day. It cannot magically acquire more energy from any other source.

Typically, few can be active enough in 24 hours to put back in a full 24 hours of power. Therefore, that 72 hours of reserve will decline rapidly.

Your 36 hours after 10 days may be pretty good. We get a lot of folks who notice that their watch stops during the night so those folks are only putting in enough to keep it running plus a few hours.

[skatamail]

Originally Posted by Tools

Every automatic watch will eventually wind down to the amount of wind that you put into it each day. It cannot magically acquire more energy from any other source.

Typically, few can be active enough in 24 hours to put back in a full 24 hours of power. Therefore, that 72 hours of reserve will decline rapidly.

Your 36 hours after 10 days may be pretty good. We get a lot of folks who notice that their watch stops during the night so those folks are only putting in enough to keep it running plus a few hours.

Great answer. Thank you!

[burnthesehills]

I think 36-48 hours after 10 days is pretty reasonable and fairly consistent with what I have experienced. Especially considering that you are only wearing the watch a few hours at a time.

I also find that the length of time on the wrist and level of activity play a factor.

[Lunaen]

Breguet overcoil should keep variation fairly consistent when the power reserve changes. Power reserve from just wearing it depends on your level of activity.

[enjoythemusic]

This is one reason why I love METAS, one of the testing specs is:

Deviation of rate between power reserves of 100 percent and 33 percent.

Here, the watch is placed in six different positions and its rate is recorded at 100 percent power reserve in each one. This process is repeated when the power reserve of the watch reaches 33 percent.

Deviation of rate between power reserves of 100 percent and 33 percent.

Omega then takes the average results of the six measures during both states of the power reserve and provides the rate deviation between the two. I believe Tudor does the same for the BB Ceramic.

[Dirt]

Originally Posted by burnthesehills

I also find that the length of time on the wrist and level of activity play a factor.

It just doesn't play a factor. It's absolutely crucial to any result.
At one end of the spectrum, imagine continuously wearing a mechanically sound Automatc winding watch(regardless of power reserve) whilst one is in a coma. The result won't be anything longer than the claimed power reserve from a full wind.
At the other end of the spectrum, if one were to wear the same watch with reasonable or adequate activity levels the watch would never stop until it dried up or wore out its internals to some degree, in which case the mechanically sound component will no longer apply anyway.
Hense the "perpetual" bit on the dial of a typical Rolex
Activity levels within the range will yield varying results.

Personally I can wear a mechanically sound Rolex for about 8 hours on a very casual day of activity and it will run for the full duration of it's power reserve before it stops after I have taken it off and put it aside.

[Dirt]

Originally Posted by skatamail

My question is specific for the Daytona with the 4130 caliber (newest models) but would generally apply.

The quoted 72hr power reserve is from fully wound. So I would expect my watch to keep time (within Rolex specs) for 72hrs if fully wound and placed on a fixed surface. (I have not tested this)

How much does the power reserve decline when just relying on wearing the watch?

In my experience, I only get 36-48hrs of power reserve when just relying on wearing the watch to keep it wound (10+ days from winding the watch). I probably wear it a few hours at a time on days when I wear the watch, and only wind it if I found it has stopped.

Your duration of wear time is obviously not enough to keep it fully wound.
The state of wind is absolutely crucial to timekeeping results as an Automatic watch is typically optimised to be running at full wind, anything much less than a full wind is going to yield poor results which will be diminishing on a sliding scale until the watch eventuall stops

[OrangeSport]

You’re just not wearing it enough