Citizen Eco-Drive is fueled by light, it never needs a battery. Eco-Drive it's unstoppable. Eco-drive technology harnesses the power of light from any light source. Both natural and artificial light are absorbed through the crystal and the dial, than a special solar cell converts light and stores it as energy. The cell recharges continuously in any kind of light. It runs for at least six months even in the dark.
The Eco-Drive 300 Meter Professional Diver watch has a 180-day power reserve, with a four day advanced low charge indicator and is accurate within +/- 15 seconds per month, and a one directional rotating elapsed-time bezel for safety.Watch charges in both sunlight and indoors. The Eco-Drive is water resistant to 999' (300 Meters), a solid one-piece case, screw-down crown with rubber wrist band and it never needs a battery. All making the 300 Meter Professional Diver one sought after timepiece. Watch purchase includes the five year US warranty.
The Eco-Drive is an analog solar powered diver's timepiece. The solar power generation function transforms solar energy into electrical energy to run the watch. Since solar energy is used as the power source of this watch, it has no need of regular replacement of the battery unlike the general diver's watches using the mercury cell, etc.
Fully charging the watch with an overhead office light is usually insufficient, to achieve a full charge from a completely depleted power reserve, however, office light is sufficient for keeping the watch continually charged. It is recommended to use natural outdoor light, or recharge indoors with an incandescent (3,000 Lux) bulb 20" away from the watch in 120 hours, outdoors, cloudy (10,000 Lux) 35 hours and outdoors, sunny (100,000 Lux) in 11 hours.
This product has a limited warranty of 60 months.