Find your model
Seiko watch batteries
Seiko quartz answers live on the calibre stamped on the caseback — not the marketing model alone. Match Cal. 6N01 / 7N42 / 8T63 (and siblings) below; Kinetic and solar secondary cells are not CR/SR swaps.
Size chart
| Retail size | Also called | Tab colour | Approx. size | Notes |
|---|---|---|---|---|
| SR621SW / 364 | SR621SW | — | Ø 6.8 × 2.15 mm | Seiko SB-AG — e.g. Cal. 6N01, 7N01, 7N89 |
| SR920SW / 371 | SR920SW | — | Ø 9.5 × 2.1 mm | Seiko SB-AN — e.g. Cal. 7N42, 7N43, 5H22 |
| SR626SW / 377 | SR626SW | — | Ø 6.8 × 2.6 mm | Seiko SB-AW — e.g. Cal. 6G27 / 6G34 |
| SR936SW / 394 | SR936SW | — | Ø 9.5 × 3.6 mm | Seiko SB-A4 — e.g. Cal. 8T63 chronograph |
| SR616SW / 321 | SR616SW | — | Ø 6.8 × 1.65 mm | Seiko SB-AF — e.g. Cal. 7N00 |
| SR916SW / 373 | SR916SW | — | Ø 9.5 × 1.65 mm | Seiko SB-AJ — e.g. Cal. 5Y85 |
Power types
| Generation / model | Battery | Replaceable? | Notes |
|---|---|---|---|
| Cal. 6N01 (current dress quartz) | 1 × SR621SW | Yes | Used on SUR609 / SUR549 / SUR611 — confirm caseback calibre. |
| Cal. 7N42 / 7N43 family | 1 × SR920SW | Yes | Common 3-hand quartz; ~5 year SB-AN class. |
| Cal. 8T63 chronograph | 1 × SR936SW | Yes | Example model SSB425 — thicker silver-oxide cell. |
| Cal. 6G27 / 6G34 | 1 × SR626SW | Yes | Official instruction specifies SEIKO SR626SW. |
| Kinetic / solar / secondary cell | Not a CR/SR swap | No | Seiko Kinetic and solar secondary cells are excluded from this disposable publish set. |
Matching devices
- Seiko SUR609
- Seiko SUR549
- Seiko SUR611
- Seiko SSB425
- Seiko SUR609 (Cal. 6N01)
- Seiko Cal. 7N42
- Seiko Cal. 7N42C
- Seiko Cal. 7N43C
- Seiko Cal. 7N01
- Seiko Cal. 7N00
- Seiko Cal. 7N22
- Seiko Cal. 7N89
- Seiko Cal. 6G27
- Seiko Cal. 6G34
- Seiko SSB425 (Cal. 8T63)
- Seiko Cal. 5Y85
- Seiko Cal. 5H22
- Seiko Cal. 5H23
- Seiko Cal. 2A22
- Seiko Cal. 6N76
Still not working?
Only after the correct calibre and cell: many Seiko quartz watches show a 2-second step as end-of-life. Prefer a dealer for water-resistant case reseal.