Renata 321 (SR616SW) — Swiss Precision Power for Slim Timepieces

The Renata 321 (SR616SW) is a silver-oxide button cell designed for precision timekeeping in compact analog watches and similar low-drain devices. With dimensions of approximately 6.8 mm in diameter and 1.65 mm in height, it provides a compact yet dependable power source for designs where internal space is at a premium.

Core Specifications

• Chemistry: Silver-oxide (mercury-free)
• Nominal Voltage: 1.55 V
• Size Code: SR616SW (~6.8 mm × 1.65 mm)
• Profile: Low-drain
• Compliance: RoHS, mercury-free

Understanding SR616SW

The code tells you everything:

• SR: Silver-oxide chemistry, round shape
• 616: Size family (~6.8 mm × 1.65 mm)
• SW: Low-drain for analog movement efficiency

Advantages of Renata 321

1. Perfect Fit for Slim Cases: Avoids movement stress and caseback interference.
2. Stable Output: Maintains accuracy throughout service life.
3. Swiss Quality Control: Ensures batch-to-batch consistency.
4. Low Self-Discharge: Long shelf life without significant capacity loss.
5. Leak-Resistant: Protects sensitive components.

Common Applications

• Dress watches with ultra-slim cases
• Compact analog devices
• Specialty timing instruments

Installation Notes

• Match SR616SW before replacing
• Handle with plastic tweezers
• Replace gaskets if caseback is opened
• Confirm polarity before seating

Performance Tips

• Keep contacts clean and free from debris
• Service movements showing high current draw
• Store unused cells in cool, dry conditions

Conclusion

The Renata 321 (SR616SW) offers precise fit and performance for slim analog watches. Its stable voltage, reliable Swiss construction, and leak-resistant build make it an ideal choice for professional service and long-term ownership.