TOOGOO(R) Li-ion Battery 1800mAh For Samsung Galaxy S II (Sprint) Epic 4G Touch SPH-D710 High Capacity reliable Lithium-Ion Battery rated at 1800mAh Expect to Approx. Double Your Talk and Standby Times This battery for you to keep as a reliable extra power source handy Output Voltage: 3.7 V Battery Capacity: 1800mAh