Community verified— Verified from trusted watchmaker & collector sources
What Battery Does Seiko SUR307 Use?
Battery
SR621SW
Silver Oxide Low Drain 1.55V
- Battery life
- ≈ ~3 years
- Voltage
- 3V
- Caliber
- 6N52
Where to buy SR621SW
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Important: Caliber 6N52 confirmed to use SR621SW (364). Not SR916SW (373) — those are for different Seiko solar models.
Compatible SR621SW Batteries
Seiko Seizaiken 364Maxell SR621SWSony MurataRenata 364Varta V364
All listed brands are direct equivalents. Always use Silver Oxide Low Drain 1.55V chemistry.
Other Names for SR621SW
SR621SW364D364V364SB-AG
See full cross-reference table How to Replace the Battery in Seiko SUR307
- SUR307 has a screw-down case back — use a case back opener tool
- Note: screw-down back provides 100m water resistance — reseal properly
- Remove old SR621SW battery with plastic tweezers
- Insert new SR621SW battery positive side up
- Screw case back back on firmly and evenly
Related Watch Models
Data verification
Battery information is based on manufacturer documentation where available and community-verified sources. If you notice an error or have official documentation for this model, please contact us to help improve this database.