MAXELL 381 SR1120SW - 1 Battery Official OEM 381/391

Product Description

381 and 391 are completely interchangeable with identical functionality

Superior Maxell Micro Silver Oxide SR1120SW One Battery 381

Do not use (inherently low performing) alkaline batteries in place of silver oxide in any timepiece.

Made in Japan
Genuine Maxell Hologram Anti-Counterfeit Packaging (other package is not genuine)
Dimensions 11.6mm Diameter x 2.05mm Height
1.55 volts 55 mAh
Mercury Free
This is a primary non rechargeable disposable battery

The 381 is a long life silver oxide chemistry with non-declining power output; alkaline batteries of the same 1.5 voltage start at 1.5 and at the half life are at .8 volts, silver oxide start at 1.55 volts and maintain the voltage until expiring. This is why silver oxide batteries are always used in watches, insulin pumps and sniper scopes or mission critical situations. Never use alkaline batteries for any device requiring a steady constant voltage. A watch with declining voltage cannot give the correct time.

Fits and Replaces: This is from the American Watchmakers-Clockmakers Institute 2008 Edition Handbook "Battery Number System". This Battery is cross-referenced as: AWCI S20, Energizer 381, UCAR 381, Eveready 381, Citizen 280-27, Duracell D381/D391, Duracell D391/D381, Duracell 10R130, Gold Peak GP81, Sylva-cell GP81, Maxell SR1120SW, Panosonic SR1120SW, National SR1120SW, Rayovac 381 Rayovac RW30, Renata 381, Renata 34, Seiko SR/TR726W, Seiko SB-BP, Seiko SB-DS, SR/TR1120SW, Seiko SB-AS, Seiko SB-DDS, Sony SR1120SW, Sony 381, Energytec SR1120SW, Energytec 381, Toshiba SR1120SW, Toshiba W1S, Varta V381, Varta 533