IWC Portuguese Perpetual Calendar in a watchwinder

Hi All,

I´m the proud owner of a IWC Portuguese Perpetual Calendar.
After a maintenance by IWC last year I noticed that the power reserve meter was slightly going down even when I was wearing this watch the whole day.
So I send my watch to IWC with the question to check the winding mechanics.
I received my watch back with the notification that did not change anything and that the watch is functioning within the parameters.

Still this is bordering me and I did a test in a watchwinder and checked the power reserve meter every day.
In my first test the watchwinder was functioning with 900 windings per day.

+/- 900 winding per 24h
Friday 9:00, power reserve meter 3,4
Saturday 21:30, power reserve meter 3,1
Sunday 9:00, power reserve meter 3,1
Monday 7:30, power reserve meter 3,5
Tuesday, 7:30 power reserve meter 3,0
Wednesday, 7:30 power reserve meter 2,2
Thursday, 8:30 power reserve meter 2,3
Friday 15:30, power reserve meter 2,1
Saturday 10:00, power reserve meter 2,4

After this test I have changed the setting ofmy watchwinder so that the watchwinder will make 2500 windings per day.
2500 windings per day is far than most watchwinders can reach in 24 for hours!
Here the results based on 2500 windings per day:

+/- 2500 windings per 24h
Tuesday 7:45, power reserve meter 3,9
Wednesday 8:30, power reserve meter 3,8
Thursday 7:45, power reserve meter 2,8
Vrijdag 10:15, power reserve meter 3,2
Saturday 9:30, power reserve meter 2,2
Sunday 10:00, power reserve meter 3,8
Monday 7:00, power reserve meter 4,1
Tuesday 8:00, power reserve meter 3,9
Wednesday 8:30, power reserve meter 2,9
Thursday 8:45, power reserve meter 2,3
Friday 20:00, power reserve meter 3,5

As you can see the power reserve meter is fluctuating even when the windings per day are the same and the power reserve is slowly going down.

Can anyone please advise me and share your experience with an IWC Portuguese Perpetual Calendar in a watchwinder.

Thank you for your input.
Leo

Leo I have called the cavalry hopefully they will come to your aid!

Welcome to the forum Leo.
Don't take ofense, but I think you should get out more. :-)

Hi Leo,
(Don't get to say that very often!)
Your watch is not functioning as it should.
It should take about 800 rotations to fully wind(7 days indicated PR)your watch.
If it continues to be rotated at the same rate,as on a winder,the power-reserve hand should not move from fully wound as the power used to run the movement is dissiapated at a much lower rate than the power charging the mainspring is being replaced.
There may be a problem with your automatic mechanism or PR indicating mechanism.
Please bear in mind that reliable movement fault diagnostics over the internet is obviously not possible. You should send your watch to your IWC service center explaining your concerns,with the data you have collected,for further investigation.
Leo

Cavalry arrived! Thanks Leo. It's nice having the head of the London service department being able to add the professional input that enables us to have our questions answered, whether for the good or not.

Thanks!
This is realy helpful and I will contact IWC again.
Best regards,
Leo