Silver Oxide Button Cells (1.55V) reference
SR626SW
377 silver oxide watch cell — 6.8 × 2.6 mm. Not the thinner 364. Alkaline LR626 fits but sags sooner.
SR626SW aliases and equivalent names
Common search labels and closely related markings include 377, 376, SR66, SR628SW. Packaging conventions vary, so confirm the compatibility grade, voltage, chemistry, and dimensions shown below before replacing the battery.
Voltage
1.55 V
Chemistry
SilverOxide
Capacity
25–30 mAh
Size
6.8×2.6 mm
SR626SW6.8 × 2.6 mm
Exact equivalents
Exact- 377 — High-drain US watch label
- 376 — Low-drain label in the same size class
- SR66 — Alternate silver oxide designation
Conditional alternatives
Conditional- LR626 — Alkaline — shorter life
- AG4 — Alkaline retail label
Do not use
Not CompatibleTechnical data
Specifications
| Specification | Value |
|---|---|
| IEC / Common Code | SR626SW |
| Chemistry | SilverOxide |
| Nominal Voltage | 1.55 V |
| Capacity | 25–30 mAh |
| Cutoff Voltage | ~1.2 V |
| Drain Class | high |
| Dimensions (D × H) | 6.8 × 2.6 mm |
| Shelf Life | ~5 years (unused, room temp) |
Typical applications
- Wrist watches
- Chronographs
- Small LED devices
- Cameras
Applications
Replacement Compatibility
SR920SW/371 is 9.5 × 2.1 mm — wider and thinner than SR626SW/377
Alkaline fits but is inferior for long-term accuracy
SR621SW/364 is only 2.1 mm thick — poor contact in 2.6 mm 377 holders
AG4/LR626 alkaline fits the size but silver oxide is preferred for watches
Side-by-side comparisons
Frequently Asked Questions
Is 377 the same as SR626SW?
Yes for shopping purposes. 377 is the common US retail label for the SR626SW silver oxide watch cell (6.8 × 2.6 mm).
Is SR628SW the same as SR626SW?
SR628SW appears in some retailer cross-reference lists for the SR626SW/377 family, but it is not the standard code for 371. Confirm 6.8 × 2.6 mm and buy SR626SW/377 when that is the required size.
Is 377 the same as 364?
No. Both are 6.8 mm wide, but 377/SR626SW is 2.6 mm thick and 364/SR621SW is only 2.1 mm thick.
Can I use alkaline AG4 instead of 377?
It often fits, but alkaline voltage sag can hurt timekeeping. Silver oxide 377/SR626SW is the better choice for watches.
What is the SR626SW battery equivalent?
Common equivalents and labels include 377, 376, and SR66. Alkaline AG4/LR626 fits the size but is a downgrade for watches. The 371/SR920SW cell is a different 9.5 × 2.1 mm size.
Should I always trust cross-reference charts?
Use this guide as a starting point, then confirm with your device manual. Chemistry and voltage must match for safe operation.
Related Batteries
Review record and primary sources
Reviewed by PlainBattery Technical Review Desk on 2026-08-25. Checked: model and alias mapping, nominal voltage and chemistry, physical dimensions, capacity range and replacement warnings.
- Silver Oxide (SR) and Alkaline Button (LR) Battery Specifications — Maxell. SR/LR model dimensions, voltage, nominal capacity and drain class.
Revision record: source citations and field-level review scope added September 11, 2026. See our sources and methodology and corrections policy.
Selection notes
377 and 376 share the same size — check your watch manual for the specified drain type. Prefer silver oxide over alkaline AG4/LR626. A listing marked SR628SW is usually trying to reference the SR626SW/377 family; 371 is a different SR920SW size.
Last verified Aug 25, 2026. Always confirm voltage, chemistry, and dimensions with the device manufacturer before replacing any battery.