364 Battery Equivalent
364
Third most common watch battery
364 and SR621SW are exactly the same battery. It is the third most widely used watch battery in the world, found in many ladies' watches, slim dress watches, and small precision instruments. Silver oxide chemistry gives a flat 1.55V discharge for accurate timekeeping.
Voltage
1.55V
Chemistry
Silver Oxide
Dimensions
6.8mm × 2.1mm
Typical battery life
2–4 years
⚠ Do not confuse with 377 / SR626SW. Both are 6.8mm diameter but the 364 is thinner (2.1mm vs 2.6mm for the 377). Fitting a 377 into a 364 compartment can damage the contacts. Always check the code on your existing battery.
All 364 equivalents
| Battery code | Type | Compatible? |
|---|---|---|
| 364 | Silver oxide | ✓ Direct replacement |
| SR621SW | Silver oxide | ✓ Direct replacement (IEC code) |
| SR60 | Silver oxide | ✓ Direct replacement |
| D364 | Silver oxide | ✓ Direct replacement (Duracell) |
| V364 | Silver oxide | ✓ Direct replacement (Varta) |
| SB-AG / SB-DG | Silver oxide | ✓ Direct replacement (Seiko) |
| 280-34 | Silver oxide | ✓ Direct replacement (Citizen) |
| 31 | Silver oxide | ✓ Direct replacement (Renata) |
| AG1 / SG1 | Silver oxide | ✓ Direct replacement |
| LR621 | Alkaline | ⚠ Same size — use silver oxide for watches |
Silver oxide vs alkaline — does it matter?
Always use silver oxide in watches — not alkaline. Alkaline equivalents have a declining voltage curve — your watch will run slower as the battery drains. Silver oxide maintains a steady 1.55V until nearly depleted, giving accurate timekeeping throughout its life.
Watches that use 364
Found in many ladies' and slim quartz watches from Seiko, Citizen, Pulsar, Bulova, Tissot, and Longines. Also used in some Casio, Orient, and dress watches. Its slim 2.1mm profile makes it popular in thin case designs.
Always check the code on your existing battery or the caseback of your watch. If unsure, a jeweller can confirm the correct size without replacing the battery.
Buy 364 batteries on Amazon
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