New Sporting Persistence 3480mAh Extended Slim Battery For AT&T Samsung Galaxy S4 mini SGH-i257 Cell Phone Battery type: Li-ion; Voltage: 3.8V; Capacity: 3480mAh Package includes : Sporting Persistence 3480 mAh Rechargeable Li_ion Battery X 1. Compatible with: Samsung Galaxy S4 mini SGH-i257 (AT&T) High Quality,100% Brand New.