Bao Xin New Standard Li-ion Backup Battery for Samsung S5820, Galaxy W, Gravity 3 Smart, Exhibit 4G etc Professional Battery with Brand High capacity business battery for Samsung.All applicable models below in description.No NFC Charging voltage:4.2V;Output voltage: 3.7V; Capacity: 1550mAh; No Memory Effect,Environmentally Friendly.Smart overcharge ,short circuit protection Made with Grade A Li-ion cells and highest quality raw materials. Certified by CE / RoHS Can be charged in phone or charger,available for more than 500 times recharge cycles