Power reserve question.

[phez]

I asked this in the General Forum but perhaps that was the wrong place.

When I woke this morning my DD40, which I wore overnight, was over 2 hours slow. No, I hadn’t reset it recently, and yes the crown was screwed down. And the second hand was still moving.

I hadn’t worn it for 30 hours, so assuming the reserve was low when I put it on, as the reserve nears exhaustion does the watch normally lose time?

I know all about giving it 40+ winds of the crown and motitoring the time keeping.

But was curious if anyone knows if the scenario I outlined has any basis in fact.

Thanks in advance for any helpful comments.

[007Sub]

Originally Posted by phez

I asked this in the General Forum but perhaps that was the wrong place.

When I woke this morning my DD40, which I wore overnight, was over 2 hours slow. No, I hadn’t reset it recently, and yes the crown was screwed down. And the second hand was still moving.

I hadn’t worn it for 30 hours, so assuming the reserve was low when I put it on, as the reserve nears exhaustion does the watch normally lose time?

I know all about giving it 40+ winds of the crown and motitoring the time keeping.

But was curious if anyone knows if the scenario I outlined has any basis in fact.

Thanks in advance for any helpful comments.

Its possible that it stopped while you were sleeping then started again if you moved before waking up. While the rate and amplitude of the balance will definitely change when the power winds down, it won't be as much as 2hrs slow over night.

[phez]

Originally Posted by 007Sub

Its possible that it stopped while you were sleeping then started again if you moved before waking up. While the rate and amplitude of the balance will definitely change when the power winds down, it won't be as much as 2hrs slow over night.

Thank you. I have wound it and it’s kept perfect time for the last 8 hours. So your explanation makes sense.

I will continue to monitor it.