Check whether reduced reserve is normal real-world shortfall or a sign the watch needs service.
If a watch claims 40 hours and a true full-wind test reaches about 34–38 hours with no other symptoms, that can still be a normal real-world shortfall. A full-wind result near 20–24 hours is a stronger service signal.
1. Fully wind the watch.
2. Set a start time.
3. Leave it untouched on a table.
4. Note when it stops.
5. Compare that number with the factory claim.
Factory claims are ideal-case figures. Temperature, amplitude, and service condition all change real results.
Why is my watch power reserve shorter than claimed?Partial wind, real-world use, aging oils, or weakened amplitude are common reasons.
How do I measure power reserve correctly?Full wind, leave untouched, record hours to stop.
When does a short power reserve mean service is needed?When a true full-wind test falls far under the claim, especially with age or other symptoms.
Is a small shortfall normal?Often yes. Many healthy watches land a bit under the headline number.