You can replace a Citizen Eco-Drive battery yourself using only your fingernails and a soft cloth
Citizen Eco-Drive watches are designed so you can swap the battery without a screwdriver or case opener. The back comes off by hand — you pry the edge with your fingernail, work your way around the case, and lift it free. Once the back is off, the battery sits in a holder you can remove with your fingers. The whole job takes five to ten minutes and costs between $5 and $15 for a replacement battery.
The catch is that Eco-Drive models vary. Some have snap-on backs that come off easily; others have threaded backs that screw on. A few models still require a case opener. Before you start, check your watch model number on the back of the case — it usually starts with BM, AW, or AT — and search for the specific manual online. Citizen publishes free PDFs for most models, and they tell you exactly whether your watch opens by hand.
Key Takeaways
- Most Citizen Eco-Drive backs pop off by hand using only your fingernail; you do not need a screwdriver or case opener.
- The battery type varies by model — common types are MT616, CR2032, and CR2016 — so check your manual or the old battery before you buy a replacement.
- Citizen publishes free manuals for every model on their website; search by your model number to confirm your watch opens by hand.
- The battery sits in a plastic holder that you lift out with your fingers; do not force it or you may crack the holder.
- Wear a soft cloth on your fingers to avoid leaving oils on the crystal and to protect the case from scratches.
Finding your watch model and battery type
Look at the back of your watch case. You will see a model number printed or engraved there — it is usually eight characters long and starts with a letter or two. Write this number down. Go to Citizen's website, click Support, and search for your model number in the manual database. read the PDF. The manual will tell you whether the back opens by hand and what battery type your watch uses.
If you cannot find the manual online, remove the old battery first (see the next section) and read the type printed on it. Common Eco-Drive batteries are MT616, CR2032, CR2016, and CR2025. Once you know the type, you can buy a replacement at any pharmacy, electronics store, or online retailer for $5 to $15. Panasonic, Energizer, and Duracell all make compatible replacements.
How to open the case back by hand
Lay your watch face-down on a soft cloth — this protects the crystal and case from scratches. Look at the edge of the back. You will see a small notch or groove cut into the rim. This is where you insert your fingernail. Position your nail in the notch and gently pry upward. Do not force it; if it does not budge, your watch may have a threaded back (see the next section).
Once you feel the back start to lift, work your way around the edge. Move your nail to a new spot every quarter-inch and pry gently. The back will come free in pieces — some backs separate as one ring, others as two or three segments. Lay each piece on the cloth in the order it came off so you remember how to reassemble it.
If your watch has a threaded back, you will see a seam that runs all the way around the edge, and the back will not budge when you pry. Stop here. Threaded backs require a case opener, which costs $10 to $30 and is not worth buying for a single battery change. Take the watch to a jeweler or Citizen service center instead.
Removing and replacing the battery
With the back off, you will see the battery sitting in a plastic holder or clip. The holder is usually white or clear plastic and holds the battery in place with two small arms or a spring. Do not touch the battery surface itself — oils from your skin can interfere with the electrical contact. Lift the holder gently with your fingernail or a plastic tool. The battery will come free.
Set the old battery aside and insert the new one into the holder, making sure the positive side (marked with a + or the shiny side) faces up. The holder will snap or clip back into place. If it does not sit flush, remove it and check that the battery is seated correctly. Press down gently until you hear or feel a click.
Before you close the back, check that the gasket — a thin rubber ring around the inside edge of the back — is clean and in place. If it is cracked or missing, the watch may not be water-resistant anymore. Wipe it with a soft cloth. If it is damaged, order a replacement gasket for your model (usually $5 to $10) before you close the case.
Reassembling the case back
Align the back pieces in the order they came off. If your back separated into multiple segments, the largest piece usually goes on first. Press the pieces together gently, working your way around the edge. You should feel them snap or click into place. Do not force them; if a piece does not fit, you may have the order wrong.
Once the back is fully seated, run your fingernail around the seam to make sure there are no gaps. The back should sit flush with the case all the way around. If you see a gap, remove the back and check the gasket again — it may have shifted out of place.
Testing the watch after battery replacement
Press the crown (the knob on the side of the case) to wake the watch. The second hand should move in two-second intervals, which means the battery is making contact and the watch is running. If the second hand does not move, remove the back and check that the battery is seated correctly in the holder. Make sure the positive side is facing up and the holder is fully clicked into place.
If the watch still does not run, the battery may be defective. Try a different battery of the same type. If a second battery does not work, the watch may have a deeper problem — a broken circuit or corroded contacts — and you should take it to a service center.
When to take your watch to a professional
If your watch has a threaded back, a case opener is the only way to open it safely. Trying to pry a threaded back with your fingernail will damage the case. A jeweler or Citizen service center can open it in minutes and replace the battery for $20 to $40 total, including labor.
If the gasket is cracked or missing, the watch is no longer water-resistant. You can still replace the battery yourself, but you should order a new gasket and install it before closing the back. If you are not comfortable doing this, a service center can do it for you.
If the watch does not run after you install a new battery, the problem is likely inside the movement, not the battery. A service center can diagnose the issue and repair it if it is fixable.
Frequently Asked Questions
What if I break my fingernail trying to open the back?
Use a plastic spoon, a credit card edge, or a plastic tool instead of your nail. Avoid metal tools — they can scratch the case. If you do not have a plastic tool, a wooden toothpick or the edge of a plastic bag can work in a pinch. The goal is to explore gentle, even pressure around the edge without gouging the metal.
Can I damage the watch by opening it myself?
If you follow the steps carefully, no. The watch is designed to open by hand. The main risks are scratching the case (use a soft cloth), damaging the gasket (handle it gently), or breaking the battery holder (do not force it). If something does not fit or move easily, stop and check the manual or take it to a professional.
How often do Eco-Drive batteries need replacing?
Eco-Drive watches charge from light, so they do not have a traditional battery that runs down. If your Eco-Drive stops running, the battery is usually dead because the watch was kept in darkness for months. Once you replace the battery and expose the watch to light, it should charge normally and run for years without another battery change.
Is the replacement battery the same price everywhere?
Prices vary. Pharmacies and drugstores usually charge $5 to $10. Electronics retailers charge $8 to $15. Online sellers on Amazon or eBay charge $3 to $8 but may take a week to arrive. Citizen service centers charge $15 to $25 for the battery alone, plus labor if they install it. Buying online and installing it yourself is usually the cheapest option.
What if I lose a piece of the case back?
If your back separated into multiple pieces and you lost one, you will need a replacement back. Search for your model number plus "case back" on eBay or Amazon. Prices range from $10 to $40 depending on the model. If you cannot find a replacement, a Citizen service center can order one for you, though it may take several weeks.