Enegitech 650mAH 3.7V 25C Lipo Battery(4PCS) with one Battery Charger for Syma X5 X5C X5SC Parts 3.7V 650mAh 20C Lipo Battery(4PCS) with one Battery Charger for Syma X5 X5C X5SC Parts Charging 4 battery at one time, Over charge protection, Short circuit protection Voltage output: 4.2V  5%; Current output: 350mAh - 410 mAh Battery slightly fat then the original one Package Included: 1 charger, 4*600 mAh batteries