10pk Exell EB-L521 Alkaline 1.5V Watch Battery Compatible With AG0 SG521 379 SR521SW The Exell EB-L521 Alkaline 1.5V Watch Battery is a popular button shape alkaline battery with a nominal voltage of 1.5V. It has a high operating voltage, high capacity, and superior low temperature characteristics. The EB-L521 is used in cameras, calculators, hearing aids, toys, watches, PDAs, remote controls, clocks, games, laser pointers, MP3 players and other non-precision electronic devices. Exell EB-L521 Alkaline 1.