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Home › Batteries › SR43
Watch battery

SR43 battery

1What it is2Safety3Other names4Tip5Facts6Buy it
  1. 1

    What it is

    SR43+ 1.55V

    SR43 is a watch battery, about as wide as a shirt button. It gives 1.55 volts.

    Get SR43 on AmazonAs an Amazon Associate, KnowYourBatteries.com earns from qualifying purchases.

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  2. 2

    Safety first

    Keep away from children and pets

    A swallowed coin or button battery can cause serious burns inside the body within 2 hours. If you think one was swallowed, get emergency help right away.

    Swallowed one? What to do now →
  3. 3

    Names you might see in the store

    All of these are the same battery. Any of them will work.

    386301SR1142D386
  4. 4

    Good to know

    This is the better version of LR43

    LR43 fits too and is cheaper, but runs down sooner.

  5. 5

    Quick facts

    Size
    About as wide as a shirt button
    Thickness
    As thick as 6 credit cards stacked
    Power
    1.55 volts
    Keeps in a drawer for
    About 5 years
    Rechargeable?
    No, use once
    Found in things like
    WatchesMedical devices
  6. 6

    Where to buy it

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

    Our pickThe exact match, 4-packEnergizer SR43 1.55V Battery (4-Pack)
    Check Price on Amazon →
    Best value10-pack, handy to keep in a drawerSR43 1.55V Battery Value Pack (10-Pack)
    Check Price on Amazon →
    Other brandDuracell D386, the same batteryDuracell D386 / SR43 1.55V Battery
    Check Price on Amazon →

    Buttons open amazon.com 🇺🇸, picked from your country.

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See it at real size

SR43 next to a US quarter and an AA battery. “Real size” matches your hand once your screen is set up in Measure it.

SR43Thickness 4.2US quarterAA

What do the letters mean?

Battery names are a code. Here’s how to read SR43:

SSilver oxide chemistry (1.55V)
RRound button form factor
43Legacy IEC size number, not a dimension. Actual size 11.6 × 4.2 mm

The same battery from each brand

BrandTheir name for it
Official nameSR43
Energizer386
DuracellD386
Renata (Swiss)386

Exact measurements

Width
11.6 mm (0.457 in)
Thickness
4.2 mm
Voltage
1.55V (empty at 1.2V)
Energy stored
120 mAh
Weight
—
Made with
Silver oxide
Works between
-10 … 60 °C
Official code
SR43

Questions people ask

Is SR43 the same as 386?

Yes. They’re the same battery with different names. You might also see 386, 301, SR1142, D386.

Can I use LR43 instead?

Yes, in a pinch. Same size, but it runs down a bit sooner.

How long will a spare keep in a drawer?

About 5 years if it stays cool and dry.

Can I recharge it?

No. Never try to recharge it.

Which way up does it go?

Usually with the side marked “+” facing you or facing up. Look at how the old one sits before you take it out.

SR43+ 1.55V
SR43Watch battery
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1What it is2Safety3Other names4Tip5Facts6Buy it