Laza Zcell Samsung Galaxy SIII 4200mah Extended Battery NFC + Back Cover (Red) Zcell powered batteries are accurately rated batteries so that means they have every drop of power they say they do. They feature high capacity, top quality and more charge cycles. Our 4200mah high capacity battery extends your Samsung Galaxy S3's battery life. Exquisite battery and cover design. Battery made from high quality Zcell lithium cells. Includes replacement back cover with a stylish finish. Capacity: 4200mah ACTUAL CAPACITY, WE DO NOT SKIMP ON POWER.