Watch battery markings explained (IEC, Renata, Energizer)
Decode SR, LR, CR, SW and W codes. Why one battery has five different names — and how to cross-reference them.
Why the same battery has many names
A single cell can be printed as 377, SR626SW, V377, D377, LR66 and AG4 — all the same battery. Each manufacturer keeps its own code for marketing.
Use our cross-reference table to translate any code to all the others.
The IEC code tells you the size
SR626SW decodes as:
| Part | Meaning |
|---|---|
| SR | Silver oxide, round |
| 6 | Diameter 6.x mm (here 6.8) |
| 26 | Height 2.6 mm |
| SW | Low drain |
For lithium CR2032: 20 mm × 3.2 mm.
Prefix cheatsheet
- SR / SG — silver oxide, 1.55 V
- LR / AG — alkaline, 1.50 V
- CR — lithium manganese dioxide, 3.0 V
- BR — lithium carbon monofluoride, 3.0 V (extreme temperatures)