Superior Maxell 379 SR521SW Micro Silver Oxide
Premium Maxell button cell Silver Oxide 379 SR521SW One Battery
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 5.8mm Diameter x 2.1mm Height
1.55 volts 14-16 mAh
This is a primary non rechargeable disposable battery
The 379 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 S56, Energizer 379, UCAR 379, Eveready 379, Citizen 280-59, Duracell D379, Mallory D379, Gold peak GP79, Sylva-cell GP79, Maxell SR521SW, Panasonic SP379, Panasonic SR521SW, National SP379, National SR521SW, Rayovac 379, Rayovac RW327, Renata 379, Renata 50, Seiko SR/TR521SW, Seiko SB-AC, Seiko SB-DC, Sony SR521SW, Sony 379, Energytec SR521SW, Energytec 379, Toshiba SR521SW, Varta V379, Varta 520