No need
for regular battery replacement

Once upon a time, everyone accepted that quartz watches had to have their batteries replaced at regular intervals. But the advent of Eco-Drive overturned the conventional thinking. Eco-Drive is a light-powered technology that drives watches by capturing light and converting it into energy using an inbuilt solar cell.
Suddenly the hassle of replacing batteries was a thing of the past.

Runs even
in dim light

Eco-Drive is designed to charge from ordinary everyday light sources like indoor fluorescent lighting and desk lights. You can go about your everyday life confident that your watch will never stop.

* To get the most out of your watch, set aside about five or six hours per month to charge it in sunlight.

Runs for over six months
even in darkness

Do you need light to generate power for your watch all the time? Not with Eco-Drive. A single full charge is enough to keep Eco-Drive working for over six months in total darkness. Indeed, some models equipped with power save function can run for as long as seven years.

* Some models run for less than six months.

As the name suggests, this is the most commonly used solar cell in our watches. It sits directly beneath the dial. Due to its excellent power-generation capabilities, it is used in many of our advanced-function models.

This ring-shaped solar cell sits above the dial, encircling it. With a ring solar cell, there is no need for the dial to be translucent, allowing for greater latitude in dial design.

[Insufficient charge warning]

This function warns you when the watch is inadequately charged by making the second hand move at two second, rather than one-second, intervals.

[Power save function]

This function, which temporarily stops the hands to save power when the solar cell is not exposed to light for a certain period, is what makes Eco-Drive's long running time possible. When light is detected, the hands resume moving as normal to indicate the time.

CITIZEN was the first company in the world to build a Light-Level Indicator into its analogue quartz watches. The indicator detects the intensity of light striking the dial and displays the current level of electricity generation, allowing the wearer to gauge the amount of power being generated at any given moment.

For watches,
a new source of energy

The first oil shock of 1973 raised global awareness and interest in alternative sources of clean energy. CITIZEN responded to the challenge by starting to develop watches driven by a completely new energy source: light.
In the 1970s, battery-driven quartz watches were very much the mainstream in Japan. Their shortcomings, however, included the hassle of having to replace and dispose of dead batteries. The desire to solve these problems and come up with something new and better was what inspired CITIZEN to develop a light-powered watch.

The world's first
light-powered analogue quartz watch

In the mid-1970s, solar cells were bulky and prone to crack. Incorporating them into something so small as a watch was far from easy. But after much experimentation and not a few dead ends, CITIZEN unveiled a design prototype of a light powered analogue quartz watch in 1974. Two years later in 1976, we unveiled the CRYSTRON SOLAR CELL, the world's first commercial light-powered analogue quartz watch.

An everyday
watch that never stops

When the CRYSTRON SOLAR CELL debuted in the 1970s, neither the solar cell (which generated energy) nor the power cell (which stored it) had sufficient generating capacity or battery life for the watch to become a realistic part of anyone's everyday life. The engineers at CITIZEN were acutely conscious of these limitations.
But as the 1980s got under way, thinner solar cells capable of generating power from indoor light and power cells with longer battery life appeared. Thanks to these advances, CITIZEN's light-powered watches made a major leap forward. We made a series of improvements and innovations with a view to creating "a watch that never stops and integrates easily into everyday life." In 1986, we debuted a model that could keep running for eight days (roughly 200 hours) on a single charge.
In 1995, through the addition of a lithium-ion power cell, we were able to develop a model with a running time of six months on a single full charge. This was a landmark achievement that led directly to Eco-Drive of the present day.

* Model shown is from 1993

Eco-Drive

CITIZEN's proprietary light-powered technology Eco-Drive is an exceptional technological achievement that also reflects our concern for the natural environment. The name and logo display our commitment to building a brand for people all over the world.