HuntHawk 3.7V 680mAh 25C Lipo Battery(4PCS) with 4 In 1 X4 Battery Charger for Syma X5 X5C, Heliway 905, Cheerson CX-30, Skytech M68, Holy Stone F180C M68 M68R, Vltoy V931, UDI 818A Charging 4 battery at one time, Over charge protection, Short circuit protection Charger Voltage input: DC 5V; Voltage output: 4.2V  5%; Current output: 350mAh - 410 mAh Size of Each Battery: 44*24*8mm Package Included: 1* 4 in 1 Charger, 4* 680mAh batteries Chargering batteries on the same time to enable your rc helicopter to have enough replaced battery so that to have longer flying time.