CRAFTSMANSHIP
Understanding Power Reserve
Trimora Editorial · March 14, 2026 · 3 min read
Power reserve is simply how long a fully wound mechanical watch will keep running before it stops. An automatic movement with a 48-hour reserve, for instance, will happily sit unworn over a weekend and still be keeping time on Monday morning.
Longer power reserves generally require either a bigger mainspring, a more efficient movement architecture, or — in some higher-end calibers — two mainspring barrels working in sequence rather than one.
It's worth checking this spec if you own more than one automatic watch and rotate between them, since anything under roughly 40 hours means a watch left unworn for a weekend will likely need resetting before its next wear.
