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Glossary

Power reserve explained

watch power reserve

Power reserve is how long a fully wound mechanical watch will run without further winding or wrist motion — often roughly 38 to 80 hours on modern movements, sometimes longer.

Why the number matters

A short reserve means a weekend off-wrist may stop the watch. A longer reserve forgives rotation in a small collection. Advertised reserve assumes a full wind; a watch worn lightly may never reach the lab figure.

Quartz and reserve

Quartz uses battery life measured in years, not hours of power reserve. When listings mention power reserve, they almost always mean mechanical. If you rotate watches, ask whether an automatic’s reserve matches your wear pattern — or whether quartz fits better.

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