The Citizen Eco-Drive, branded as such in 1995, is a family of light-powered quartz watches. A solar cell under the dial charges a rechargeable battery, so the watch does not need a battery change for years, and it keeps running in the dark for months after a full charge. Eco-Drive is a technology across many models and case sizes, not one reference, so no single set of specifications applies.

Citizen had shown a solar analogue watch in 1976, the Crystron Solar Cell, and Eco-Drive was the version that reached a wide market in the 1990s. It later added titanium cases, perpetual calendars, radio-controlled models and dive watches, and the name came to cover most of the brand’s range.

The community regards Eco-Drive as a practical and reliable technology rather than a collector’s prize, and its value is in long service with little maintenance. The technology is still in production across Citizen’s current line.