CellChart
Silver-oxide watch (SR)

SR920SW battery: equivalents & specs

The SR920SW is the 371, one of the world's best-selling watch batteries. It is a 1.55 volt silver-oxide cell, 9.5 mm across and 2.05 mm tall, holding 35 to 40 mAh, and it powers a huge share of midsize and men's analog quartz watches.

SR920SW battery drawing: 9.5 mm across, 2.05 mm thick SR920SW 1.55V + ⌀ 9.5 mm 2.05 mm
SR920SW, face and side profile, drawn to scale: 9.5 mm across, 2.05 mm thick.
Voltage
1.55 V
Size (D×H)
9.5 × 2.05 mm
Chemistry
Silver oxide (Ag2O)
Capacity
35-40 mAh

Same battery, other names

Every code below is the exact same cell as SR920SW. Any of them will fit and work identically.

371SR69V371D371SR920W (370, high drain)

Compatible replacements

  • LR920 / AG6: Alkaline same-size cell; fits, but with roughly half the watch life.

Buying and replacement notes

Alongside the 377 and 364, the 371 completes the trio of watch batteries that cover most of the quartz watches ever made. The high-drain 370 (SR920W) shares its case for watches with lights, alarms or chronographs. Counterfeit premium-brand cells are common in marketplace listings at this size; a genuine Murata or Renata 371 from a proper supplier costs little more.

Commonly used in

analog quartz watchesmen's dress watchesmidsize movements

Need a replacement?

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⚠️ 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 battery can I use instead of a 371?
Any SR920SW is the identical cell regardless of brand: 1.55 V silver oxide, 9.5 x 2.05 mm. The 370 (SR920W) fits the same slot and suits high-drain watches. The alkaline AG6/LR920 also fits but roughly halves service life in a watch.
How long does a 371 battery last?
Two to four years in a standard analog quartz watch. The 371's capacity is generous for a low-drain movement. Replace it promptly once the watch stops; a fully spent cell left inside for months is the main cause of leak damage to movements.
371 versus 370: does it matter?
For a plain three-hand watch, the low-drain 371 is the design-intended cell and lasts longest. For a watch with an alarm, backlight or chronograph, the high-drain 370 keeps voltage steady through current spikes. Physically they are interchangeable.

More Silver-oxide watch (SR) cells

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