Renata 321 (SR616SW) Silver‑Oxide Watch Battery

The Renata 321 (SR616SW) is a compact, low‑drain silver‑oxide button cell for slim analog watches and similar precision devices. It fits tight spaces while delivering a stable 1.55 V output for consistent timekeeping.

Key specs

When to choose this cell

• Use if your watch or device explicitly specifies SR616SW or 321.
• Best for low‑drain analog movements in very small or ultra‑slim cases.
• Choose silver‑oxide over alkaline for steadier voltage and longer run time.

Avoid or check alternatives if

• Your manual calls for SR616W (high‑drain) or another size.
• You are considering LR616 (alkaline) as a substitute — expect shorter life and less stable voltage.
• The device is digital or has high current features (alarms, lights, sensors) that may need a high‑drain variant.

Compatibility and cross‑references

Common equivalents (verify the “SW” low‑drain suffix on the package):

• IEC: SR616 (SW)
• Generic: 321, 616
• Brand labels: Renata 321; Energizer 321; Maxell SR616SW; Murata/Sony SR616SW; Panasonic SR616SW; Varta V321; Seizaiken SR616SW; GP 321

Installation and handling

1. Match the code: use SR616SW/321 only if specified by the device.
2. Open the case carefully; protect gaskets to preserve water resistance.
3. Handle with non‑metallic or plastic tweezers to avoid shorting and fingerprints.
4. Clean the battery contacts; remove any oxide or debris with a lint‑free swab.
5. Observe polarity: the flat side is typically (+). Confirm before seating.
6. After closing, check timekeeping and functions; pressure‑test water‑resistant watches if applicable.
7. Recycle the old cell at a battery collection point.

Performance tips

• Store spares in original packaging at 50–77°F (10–25°C), low humidity; do not freeze.
• If a new cell drains quickly, the movement may need service (high current draw, dried lubricants, or corrosion).
• Do not mix new and old cells or different chemistries in multi‑cell devices.

Safety and disposal

• Keep away from children — button batteries are a choking and ingestion hazard. If swallowed, seek immediate medical attention.
• Do not recharge, disassemble, heat, or incinerate.
• Recycle according to local guidelines for button cells.

FAQ