Movement
Solar (Light-Powered)
Light charges a cell that can run for months in the dark.
- Typical accuracy
- Quartz-grade: typically ±15 seconds per month.
How it works
A photovoltaic cell under the dial converts light into electricity, stored in a rechargeable capacitor that drives a quartz movement. Any light — even indoor — tops it up. Citizen's Eco-Drive and Seiko's solar lines popularized the tech as a low-maintenance alternative to disposable batteries.
Strengths
- No battery changes for many years
- Very low maintenance
- Environmentally friendlier than cells
- Runs months in darkness on a full charge
Trade-offs
- Capacitor degrades after 10–20 years
- Quartz tick, not a sweep
- Deep discharge can need a full re-charge to restart
Care tips
How to keep one running well between services.
- Give it periodic light exposure to keep the cell topped up
- Avoid leaving it in the dark for very long periods
- The capacitor is replaceable during a service
Keep reading
- Movement
Meca-Quartz
Quartz timekeeping with a mechanical chronograph.
- Movement
Kinetic
Wrist motion generates electricity for a quartz movement.
- Movement
Tuning Fork (Accutron)
A humming fork instead of a ticking balance wheel.
- Movement
Digital (LCD/LED)
A quartz movement with a screen instead of hands.
- Complication
Date
The most common complication — the day of the month.
- Complication
Chronograph
A stopwatch built into the watch.