Glossary/Power Reserve

Power Reserve

Power reserve is a term that is widely used to refer to the maximum amount of potential energy that can be stored in the mainspring of a watch or clock movement, which can be released as kinetic energy to power a spring driven timepiece. It is measured by the number of hours that a watch or clock can run for, starting from a fully wound state and ithout any interm winding.

The term can also be used to refer to a complication that indicates to the user the remaining amount power or number of hours that a timepiece will continue to run for.