UUMART 3.7v 600mah 25c Lipo Battery(4pcs) with 4 in 1 X4 Battery Charger for Syma X5 X5c Parts 3.7V 650mAh 25C Lipo Battery(4PCS) with 4 In 1 X4 Battery Charger for Syma X5 X5C Parts Voltage output: 4.2V  5%; Current output: 350mAh - 410 mAh Charging 4 battery at one time, Over charge protection, Short circuit protection Package Included: 1 charger, 4*600 mAh batteries Battery slightly fat then the original one