What Is Citizen's ECO-DRIVE Technology?
Imagine your wristwatch running for months in darkness, needing no cable or adapter to charge, and regaining the energy it has lost every time it is exposed to sunlight or even room light. This is exactly the idea Citizen has pursued with its Eco-Drive technology; a ...
0 Posted by: Saeed Rad on October 21, 1405 at 11:38
Imagine your wristwatch working in the dark for months, not needing a cable or adapter to charge, and regaining its lost energy every time it is exposed to sunlight or even room lighting. This is exactly the same idea that Citizen followed with Eco-Drive technology; An optical energy supply system that eliminates the need for the watch to periodically replace the battery.
Eco Drive is a power supply technology that combines a light absorption cell, an energy conversion circuit, a rechargeable storage cell and an energy-efficient quartz motor. The result is a watch that works in normal use without a disposable battery, has the accuracy of quartz models and, unlike a smart watch, does not look for a charger every night.
Eco-Drive is the proprietary technology of the Japanese company Citizen that converts natural and artificial light into electrical energy. After passing through the energy management circuit, the generated energy is stored in a rechargeable secondary cell and drives the quartz movement of the watch. Therefore, the phrase "without battery" that we sometimes hear about these watches is not completely accurate; Eco Drive does not have a disposable battery, but uses an internal rechargeable cell to store electricity.
Different Eco Drive models differ in terms of energy storage capacity, charging speed and features. However, most common models can work in the dark for at least six months after a full charge. Some calibers equipped with energy storage mode last much longer, and in certain models, this interval even reaches several years.
To see the variety of models, compare specifications and choose from among men's and women's watches, you can refer to the representative page of the original Citizen watch in Iran. When comparing, don't just focus on appearance; Model code, motor caliber, energy storage, glass material and water resistance determine the real difference between the options.
How does Eco-Drive technology work?
The Eco Drive mechanism looks complicated, but the energy path is understandable. The light passes through a screen that is designed in such a way that both the appearance of the watch is preserved and enough light reaches the cell below it. The photocell converts this radiation into electricity, and the energy enters the storage unit after being adjusted by the internal circuit.
The work steps can be summarized as follows:
Sunlight, daylight or artificial lighting shines on the clock face.
The photovoltaic cell under the screen converts light into electrical energy.
The energy management circuit controls the generated electricity and transfers it to the charging cell.
The stored energy keeps the quartz movement and functions of the watch active.
The extra energy is stored for when the watch is under the sleeve, in a drawer or in a dark environment.
Eco Drive is not the name of a specific model, but the energy supply technology that is used in various Citizen collections. For this reason, watches equipped with this technology range from elegant women's models and formal men's watches to diving, titanium and chronograph models. The difference between these models is mostly related to the design, body material, facilities and type of use.
Women's Eco Drive watches usually have a more delicate frame, less weight and more diverse colors. Among them, you can see both simple and everyday models and watches with a shell dial, two-tone strap or jeweled markers. The smaller dimensions of the frame do not change the technology, and these models are also charged with natural or artificial light.
The Citizen Eco Drive men's watch includes a wide range of formal, sports, diving and professional models. Classic three-hand models are suitable for everyday use and work environment; On the other hand, sports and diving models usually have a larger frame, more legibility and more complete features.
Citizen Eco Drive watch with three motors
In the Iranian market, the term Citizen Eco Drive with three motors is mostly used for chronograph models with three sub-dials. These dials can display chronograph seconds, minutes or 24-hour time depending on the caliber of the watch. Three-motor is more of a common market term; Therefore, when buying, the use of subdials and the exact caliber of the model should be checked.
Diving models are usually equipped with rotating bezel, luminous indicators, resistant crown and higher water resistance. Some of these watches meet professional diving standards, but the mere appearance of diving or the presence of a bezel does not mean that the watch is suitable for professional diving. The level of water resistance should be checked from the specifications of the same reference.
In some models, Citizen uses Super Titanium alloy, which is lighter than steel and has good corrosion and scratch resistance. These watches are a more comfortable choice for people who don't like heavy steel frames or keep the watch on their wrist for long hours.
Classic Eco Drive models usually have a quiet screen, simple frame and leather or steel strap and are suitable for formal style. On the other hand, sport and field models are made with a more readable screen, a more resistant body and a larger design. This variety has made Eco Drive not only for expensive or professional watches and it is possible to choose a suitable model according to style, budget and type of use.
The story of Eco Drive started with the energy crisis
The roots of Eco-Drive technology go back to the 1970s and the global energy crisis. During that period, increasing attention to clean sources led Citizen Engineers to investigate the use of light as a clock power source.
1976; The birth of the first optical analog clock
The result of Citizen's research was shown in 1976 with the introduction of Crystron Solar Cell; The world's first optical analog watch that received its required energy from light.
Limitations of the first generation Eco Drive
Early solar cells were large and tied the hands of designers to make a variety of panels. The amount of energy storage was also limited compared to today's models. Over the following years, Citizen made its energy-efficient cells, circuits, and motors smaller and more efficient.
The name Eco-Drive was introduced in 1994. A year later, the use of a secondary lithium battery enabled the watch to run for about six months on a full charge; The development that made Eco Drive one of the main technologies of Citizen.
From a 1 mm motor to a 365-day charge
In 2016, the Eco-Drive One watch with a 1 mm ultra-thin motor was introduced. In 2023, Citizen also released the E365 caliber, which can continue to work for approximately 365 days with a full charge.
Does the Eco Drive watch really have no battery?
Let's put it simply: there is no ordinary battery inside the Eco Drive watch that you have to replace every two or three years. Instead, there is a secondary rechargeable cell that stores the energy received from the light. In some writings, this part is called a "capacitor", but in many newer calibers, we are actually dealing with a specialized charge cell.
This cell is charged many times and has a much longer life than a disposable battery; However, extreme heat, frequent full discharge or improper maintenance can reduce its capacity. An old watch stopping prematurely after a full charge is a sign for a professional check.
How is Citizen Eco-Drive charged?
In daily use, you do not need to do anything special. When the watch is on the wrist and the screen receives ambient light, the charging process continues automatically. Sunlight is the fastest option, but window light, LED lamps, and moonlight can also generate energy; They just need more time.
Follow these tips for better charging:
Place the clock so that its face is directly facing the light source.
If it is left in the box for a long time, first get help from daylight or mild sun.