SR44 battery: equivalents & specs
The SR44 is the king of silver-oxide button cells: 1.55 volts, 11.6 mm across, 5.4 mm tall, and 150 to 200 mAh of capacity. Sold as the 357 (high drain) or 303 (low drain), it is the premium replacement for the ubiquitous alkaline LR44.
Same battery, other names
Every code below is the exact same cell as SR44. Any of them will fit and work identically.
Compatible replacements
- LR44 / AG13: Alkaline same-size cell; cheaper, with roughly half the capacity and a sloping discharge curve.
Buying and replacement notes
The 357 earned its reputation in precision gear. Digital calipers, classic light meters and quality watches all specify it because it holds 1.55 V within a few hundredths of a volt for nearly its whole life, then drops off quickly at the end. An alkaline LR44 in the same instrument starts at 1.5 V and sags continuously, which shifts readings on voltage-sensitive meters.
Buy the 357 for anything with a motor, display or measurement function, and the 303 for plain analog watches. Both cost more than an LR44 but typically deliver two to three times the service life in real devices, making the silver cell cheaper per month of use.
Commonly used in
Need a replacement?
Shop SR44 batteries on Amazon →Comparisons
⚠️ 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.