What is a SR1120SW battery?

SR1120SW is a silver-oxide watch cell (about 11.6 × 2.1 mm). Jeweller packs often say 381 (391 is the related SR1120W label). Not a lithium CR coin. See watch battery size codes.

What do the letters in SR1120SW mean?

S is silver oxide in the IEC system (S happens to match silver), and R means round. Same size with an LR prefix is alkaline — related size family, not the same battery. Full guide: CR vs LR vs SR.

What is SR1120SW also called?

SR1120SW pack labels and aliases on this site include 381, 391, SR1120W, V381, V391, D381, D391, SR55. These are names for the same battery entity — not chemistry substitutes.

Battery

SR1120SW

1.55V silver oxide button cell

V381 is a pack label for SR1120SW — same battery, different name on the package.

Chemistry: silver_oxide
Voltage: 1.55 V
Diameter: 11.6 mm
Thickness: 2.1 mm
Used by: 0 devices

Common uses: Watches

Common questions

What is a SR1120SW battery?: SR1120SW is a silver-oxide watch cell (about 11.6 × 2.1 mm). Jeweller packs often say 381 (391 is the related SR1120W label). Not a lithium CR coin. See watch battery size codes.
What do the letters in SR1120SW mean?: S is silver oxide in the IEC system (S happens to match silver), and R means round. Same size with an LR prefix is alkaline — related size family, not the same battery. Full guide: CR vs LR vs SR.
What is SR1120SW also called?: SR1120SW pack labels and aliases on this site include 381, 391, SR1120W, V381, V391, D381, D391, SR55. These are names for the same battery entity — not chemistry substitutes.

Other names

Genuine aliases and pack labels for this battery — not substitutes of a different chemistry.

381 · 391 · SR1120W · V381 · V391 · D381 · D391 · SR55

Related codes

Same battery / other names

SR1120SW381

Also sold as

Renata/watch-trade 381 → SR1120SW

Rechargeables are not equivalents

Do not substitute a rechargeable cell unless the device documentation explicitly allows it. Silver-oxide and lookalike chemistries are not interchangeable with rechargeables by size alone.

Size family

Edge thickness in the 11.6 mm family — thicker bar means thicker cell. Not to scale. Highlighted cell is this page.

1.65 mm

2.1 mm

2.1 mm

3.1 mm

3.1 mm

3.6 mm

4.2 mm

4.2 mm

5.4 mm

5.4 mm

5.4 mm

5.4 mm

Devices using SR1120SW

No devices listed for this battery yet.

Learn more

Testers & chargers

Optional tools that fit this cell type — only where the chemistry allows. Separate from the battery answer.

Amazon links may earn us a commission. They do not change the battery answer.

Coin cell / button cell battery tester
Quick check of CR / LR / SR button and coin cells before fitting
Buy on Amazon More tools
ZTS Mini-MBT Multi-Battery Tester
More informative state-of-charge style checks across common formats
Docs Buy on Amazon More tools
BT-168D-class digital battery tester
Budget household go/no-go checks
Buy on Amazon More tools

Coin / button cell tester
Quick check for CR / LR / SR coin cells
Open-circuit voltage alone does not prove remaining capacity.
How to test a coin cell Buy on Amazon

Buy links are optional and separate from the battery answer.

Need one?

Need a SR1120SW?

Search Amazon for packs of this battery code.

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Notes

Renata/trade 381 (391 ≈ SR1120W). Silver oxide watch cell.