: While it doesn't need standard batteries, the rechargeable cell typically lasts 10–20 years before needing professional service (Citizen Support). How to Set Your Citizen Eco-Drive
Email Citizen Japan or your local Citizen subsidiary (e.g., Citizen Watch America) with a photo of the case back. Provide the string GN-4W-S-12G. Their archivists can cross-reference production codes. citizen eco drive gn-4w-s-12g manual
[Current Date] Subject: Informational summary regarding the user manual and specifications for the Citizen watch model GN-4W-S-12G. : While it doesn't need standard batteries, the
If the watch is behaving erratically (hands not moving correctly, buttons not working), you may need to perform an "All Reset." buttons not working)
Once you have those 4 characters, you can download the official guide from the Citizen Operation Manuals page. Essential Eco-Drive Care