Watch battery chart

Trade number → IEC silver-oxide code. Alkaline same-size twins are listed for clarity — not as swaps.

Prefer the empty cell or the movement docs. If the maker names silver oxide (SR), do not substitute alkaline (LR / AG) for longevity-critical watches. Full map: watch battery size codes.

Trade #	IEC (silver oxide)	Alkaline twin (not equivalent)	Notes
364 / 363	SR621SW	LR621	Thin 6.8 × 2.15 mm
377 / 376	SR626SW	LR626	≈6.8 × 2.6 mm
371 / 370	SR920W	—	Also SR920SW family
392 / 384	SR41	LR41	≈7.9 × 3.6 mm
357 / 303	SR44	LR44	≈11.6 × 5.4 mm
389 / 390	SR1130	LR1130	≈11.6 × 3.1 mm — not LR44 height
395 / 399	SR927SW	—	Common quartz calibre cell
321	SR616SW	—	—
329	SR731SW	—	—
337	SR416SW	—	—

Common confusion pairs

LR626 vs SR626SW LR621 vs SR621SW LR44 vs SR44 SR1130 vs LR1130 LR1130 vs LR44

Module-led finders: Casio · Seiko · Citizen · Orient · Match by measured size