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Silver-oxide watch (SR)

SR43 battery: equivalents & specs

The SR43 is a high-capacity 1.55 volt silver-oxide cell, 11.6 mm across and 4.2 mm tall, holding 120 to 130 mAh. It is sold as the 386 (SR43W, high drain) and 301 (SR43SW, low drain), and it directly replaces the alkaline LR43/AG12.

SR43 battery drawing: 11.6 mm across, 4.2 mm thick SR43 1.55V + ⌀ 11.6 mm 4.2 mm
SR43, face and side profile, drawn to scale: 11.6 mm across, 4.2 mm thick.
Voltage
1.55 V
Size (D×H)
11.6 × 4.2 mm
Chemistry
Silver oxide (Ag2O)
Capacity
120-130 mAh

Same battery, other names

Every code below is the exact same cell as SR43. Any of them will fit and work identically.

386301SR1142SR43W (386)SR43SW (301)

Compatible replacements

  • LR43 / AG12: Alkaline same-size cell with lower capacity and drooping voltage.

Buying and replacement notes

With over 120 mAh available, the SR43 approaches small-device territory rather than pure watch duty; older cameras, meters and calculators specified it heavily. The 386 is the number to ask for in general use, with the 301 reserved for low-drain analog watches. Its 4.2 mm height distinguishes it from the shorter 389 and the taller 357 in the same 11.6 mm diameter.

Commonly used in

watchescalculatorsphotographic equipmentmedical instruments

Need a replacement?

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Comparisons

LR43 vs SR43

⚠️ Keep away from children. Swallowed button batteries, especially 20 mm lithium coins, cause severe injury within hours. If a child swallows one, call the 24/7 National Battery Ingestion Hotline (US) at 800-498-8666 or poison control at 800-222-1222 immediately. What every parent should know.

Frequently asked questions

What is a 386 battery equivalent to?
The 386 is the SR43W, an 11.6 x 4.2 mm silver-oxide cell at 1.55 V. The 301 (SR43SW) is the same cell tuned for low drain, and the alkaline LR43/AG12/186 shares the size at 1.5 V. Any of them fits a 386 compartment; the silver cells perform best.
Is the 386 the same as the 357?
No. Both are 11.6 mm silver-oxide cells, but the 386 (SR43) is 4.2 mm tall while the 357 (SR44) is 5.4 mm. The 357 will not fit a 386 compartment. They are neighbors in a size family, not equivalents; check the old cell's marking.
How long does an SR43 last?
In a watch, three years or more given its large capacity. In vintage cameras and meters, life depends on usage but typically spans years of normal shooting. Its low self-discharge means it also stores well, losing only a few percent of charge per year.

More Silver-oxide watch (SR) cells

SR416SWSR512SWSR516SWSR521SWSR527SWSR616SWSR621SWSR626SWSR716SWSR721SW