How Does Citizen Eco-Drive Work? Easily Explained

Citizen’s Eco-Drive is one of the most advanced technologies in today’s quartz watches. While I am not a big fan of quartz watches, I love technology. Therefore, I wanted to investigate what Citizen’s Eco-Drive technology is all about, is it worth the money, does it need a battery change, how long does it last, etc.

Citizen Eco-Drive is a solar panel integrated in the dial of the watch. The Eco-Drive technology takes any light source and converts it to energy stored in the power reserve. Citizen’s Eco-Drive can run without any light for 6 months on a full charge.

Citizen is one of the affordable watch brands that have a good reputation while being worth its money. So what gives the good value?

How Does Citizen Eco-Drive Work?

Citizen’s Eco-Drive is a technology which takes any light source and converts it into energy. The light source can be literally anything, a lamp, the sun, a computer screen, anything. The more efficient the light source is, the faster it charges. Everything the Eco-Drive picks up is stored in an electrical power cell, the capacitor.

When there is sufficient light, the Eco-Drive will use the energy collected to run the watch. If the light source is inadequate, it will use the energy stored in the capacitor.

The general guidelines for charging the watch it applies:

  • At 20 cm (8 inches) distance from a light source of 3,000 lux (equivalent to being in an office or close to a window), the Eco-Drive stores 1 day of use in 40 minutes. The watch will be fully charged after 130 hours.
  • Shade or overcast day at 10,000 lux (equivalent to being under a parasol, the eaves, or a day with rain), the Eco-Drive will store 1 day of use in 12 minutes. The watch will be fully charged after 40 hours.
  • Outside on sunny days at 100,000 lux (equivalent to direct sunlight at a summer day) will generate 1 days use in 2 minutes and will be fully charged in 11 hours.

The Eco-Drive watches from Citizen can run for at least 6 months in complete darkness. If you have a collection of watches, you will have no problem with throwing the Citizen Eco-Drive in the drawer and first pick it up a half year later. If that isn’t cool, I don’t know what is.

Some Eco-Drive watches are equipped with 2 unique features: Power saving function and Light-level power indicator. The power-saving function is made to save the energy of the watch. When the watch senses darkness, it stops the watch from moving. Once light hits the dial, it quickly moves back to the correct time. The light-level power indicator is a feature showing how much the watch is charging at a glance.

Are Citizen Watches Worth The Money?

Citizen watches are by modern standards high-quality watches compared to the value you are getting. They are definitely worth the money. The value provided by Citizen watches are massive compared to the cost. The Eco-Drive Technology keeps you from replacing the battery every 2-3 years, and the reliability of the watches are great.

If you have your eyes on a specific Citizen model and wondering whether you should buy it, the quality of the watch shouldn’t be a concern to you. However, that is not to say there isn’t some worthy competitors. A brand like Seiko performs very well and has an excellent reputation within their diving watches.

Citizen has included a feature that warns you if it becomes low on power. Most watches just die, and you will have to take them to a jeweler or watchmaker. With Citizen’s Eco-Drive, you just place the watch in light, and it will start charging, avoiding going to a jeweler or watchmaker for a battery change.

How Long Does A Citizen Eco-Drive Last?

Citizen’s Eco-Drive technology will last for more than 10 years, with the capacitor is expected to last 20 years.

Generally, when talking about quartz watches (watches power by current going through a mineral called a quartz crystal), they are expected to last a long time (+20 years). Even more so with modern quartz watches. Some quartz, and therefore Citizen Eco-Drive, watches are expected to last about the lifetime of the owner.

The longevity of Citizen’s Eco-Drive is also a factor of how you treat the watch. If you take it in the hot tub, snowboarding, scuba diving, and other extreme degradable activities you watch will, of course, wear out quicker. Surely the watch can last just as long as other quartz watches if maintained and cared for.

There are different aspects to how long the watch will last. Surely the case of the watch will be degraded if used in extreme conditions or worn irresponsibly. However, the Eco-Drive technology power cells (not the capacitor) will last up to 40 years. The charge capacity will diminish over time. Yet, the cells are rated at 80% capacity even after 20 years.

Do Citizen Eco-Drive Watches Need New Batteries?

A Citizen Eco-Drive watch does not need a battery. It is a common misconception that they have batteries. However, they have capacitors, which is where energy is stored. The capacitor is only used when there is no light source to drive the watch. Otherwise, it uses the light source directly to run the watch.

Changing the Capacitor Of Citizen Eco-Drive Watch (Watch keeps going without a capacitor)

The capacitor on the Eco-Drive can go bad, and therefore, you might need to go to the watchmaker to get a replacement. However, the battery found in a standard quartz watch will not work for Citizen’s Eco-Drive technology. It needs a special connector which is aligned in the watch. The special connector is what makes the Eco-Drive charge the capacitor.

Is Citizen Eco-Drive Water Resistant?

The water-resistance of the watch depends on the rating. The rating is commonly indicated in BAR, ATM, or meter/ft. The activities you can participate in with your watch is dependent on the water resistance rating. Below is a table of the general terms of water resistance to a watch.

Water Resistance Chart>50 Meters
100 Meters
200 Meters
<300 Meters
Splashes/Washing hands/Rain
Beach/Swimming pool
Water activities (Jetski, water skiing, pool parties, etc.)
Light diving
Serious diving (Scuba diving)
Water Resistance Chart

Water-resistance is a good thing to have on a watch, which is intended for everyday use. A watch marked with water-resistance of 5 or below should not be exposed to water. However, watches with a water resistance of 3 ATM can withstand water splashes from washing hands and light rain. Still, they shouldn’t be used near water, if possible.

Why Is Your Eco-Drive Watch Stopped?

The most common reason an Eco-Drive watch stops is if the watch is completely drained from energy. If it is running slowly, it might be an indication that the movement should be serviced.

If the second hand on the watch jumps 2 seconds at a time or 1/3 of a minute on watches without seconds hands, it means the reserve power is getting low. The power cell needs to be fully exposed to a strong light source. If it keeps to move 2 seconds at a time, you might need to reset the watch. On most models, it is done by pulling the crown to the time setting position for 30 seconds and then return the crown to the closed position next to the case, and then finally set the time.

Jonas Henriksen

AllInWatches is founded by Jonas, who has a great interest in mechanical watches. All aspects of manual and automatic (mechanical) watches is a big interest and have been a passion since 2015, where the first automatic watch was purchased. Seeing the transparent case back and discovering the heritage of watchmaking piqued an interest in horology.

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