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Home › Can I swap? › SR1120SW vs SR42
Can I swap?

SR1120SW vs SR42: can you swap them?

1The short answer2Both ways3Differences4Buy it5Learn more
  1. 1

    The short answer

    NoSR1120SW can stand in for SR42, but not the other way roundThey’re the same width and power, but SR1120SW is thinner. It may wobble a little and runs out about 50% sooner. SR42 is too thick to fit where SR1120SW goes.
    SR1120SW+ 1.55V
    SR1120SWAs thick as 3 credit cards stacked
    SR42+ 1.55V
    SR42As thick as 5 credit cards stacked
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  2. 2

    Both ways round

    Can I put SR42 where SR1120SW goes?No
    Can I put SR1120SW where SR42 goes?In a pinch
  3. 3

    What’s different

    SR1120SWSR42
    SizeAbout as wide as a shirt buttonAbout as wide as a shirt button Same
    ThicknessAs thick as 3 credit cards stackedAs thick as 5 credit cards stacked
    Power1.55 volts1.55 volts Same
    KindWatch batteryWatch battery

    Lasts longer: SR42 (about 100% longer)

  4. 4

    Where to buy SR1120SW

    As an Amazon Associate, KnowYourBatteries.com earns from qualifying purchases.

    Amazon searchEnergizer listings, any pack sizeSearch Amazon for Energizer 381
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    Amazon searchMulti-packs from any brandSearch Amazon for SR1120SW multi-packs
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    Amazon searchDuracell D381 listings, the same batterySearch Amazon for Duracell D381
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  5. 5

    Learn more

    About SR1120SWAbout SR42Check another pair
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Questions people ask

Can I use SR42 instead of SR1120SW?

No. They’re the same width and power, but SR1120SW is thinner. It may wobble a little and runs out about 50% sooner. SR42 is too thick to fit where SR1120SW goes.

Can I use SR1120SW instead of SR42?

In a pinch. They’re the same width and power, but SR1120SW is thinner. It may wobble a little and runs out about 50% sooner. SR42 is too thick to fit where SR1120SW goes.

Which one lasts longer?

SR42 (about 100% longer).

All the numbers

SR1120SWSR42
Diameter11.6 mm11.6 mm
Height2.1 mm3.6 mm
Nominal voltage1.55V1.55V
Typical capacity50 mAh100 mAh
ChemistrySilver oxideSilver oxide
Shelf life5 yrs5 yrs
Operating temp-10 to 60 °C-10 to 60 °C
Can I use SR42 instead of SR1120SW?No
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1The short answer2Both ways3Differences4Buy it5Learn more