If you wore an eco drive watch or have seen one, you might have wondered how this watch that requires absolutely no battery change work? Does it not need any energy? If it does, where does it derive its energy from? How does the eco drive watch work?
Ever since wrist watches were introduced, there was fierce competition amongst the major watch manufacturers. Citizen, Seiko, Omega, Rolex etc. were in a constant race to develop and market technologically superior wrist watches. In the 70’s when digital watches were introduced, people who wore them had to constantly change batteries. The quartz wrist watches introduced in the late 70’s and early 80’s, required less power but still needed a battery change once every couple of years if not earlier.
It was during this time that watch manufacturers wondered if they could do away with the need for batter replacement. Seiko came up with a watch that could generate power simply by the movement of the hand. While it did meet with some commercial success, the idea did not catch on because the watch would begin to go slow during the night when it was placed on the table or in a drawer.
The 80’s also saw the commercialization of another development – solar energy. Citizen watches began secretly researching the use of solar energy as a power source for the wrist watch. To overcome times when the watch would be kept or used in dark places, Citizen also developed a battery that could store enough power on a single charge so as to supply the watch with all its energy needs for at least five years.
After almost a decade of research, Citizen perfected a watch aptly named, ‘eco drive’ short for ‘ecological drive’. This watch could generate power from even a candle light source. Once charged, the internal battery could store enough power to run the watch for months. Based on the quartz technology, the watch was also amazingly accurate.
Today, the Citizen Eco drive watch is a runaway commercial success and graces the majority of the Citizen Watch models on sale today.
How does Eco-Drive work?
Under the dial of the Eco drive watch is a silicon light cell. When light filtered through the dial hits the light cell, it generates electricity which is used to recharge the amazing titanium lithium ion battery. The battery in turn, provides highly stable energy required to power the quartz movement of the watch.
After a single charge, initial Citizen Eco drive watch models could last 30 days in absolute darkness and keep perfect time. Over the last decade, the power generation and storage became even more advanced and Eco drive watches sold today can after a single charge, run for several months in total darkness. Since most us don’t live in caves or in dark places, the eco drive watch runs perpetually without you ever requiring changing its battery.
Since there is no need to replace the battery, there is no battery to discard or pollute the Earth. Citizen Ecodrive watches are without doubt, an amazing technological marvel.