Indonesia, as one of the biggest contributor to air pollution, has a solution to replace petroleum-powered motorized vehicles with battery-powered electric vehicles (EVs). Indonesia has nickel reserves that can be used as one of the cathodes of a Li-ion battery called NMC. In this research, the author uses ferronickel ore from the smelting process of laterite nickel ore. Then ferronickel is leached to produce nickel sulfate. This research was conducted to determine the effect of variations in leaching time (2 hours, 4 hours, 6 hours, 8 hours, 10 hours) on the extraction rate, extraction percentage, chemical composition, yield, and the resulting compounds. The results of this study were that the highest content of nickel extract was produced in a 10-hour variation of 11530 mg/L with an extraction percentage of 94.16%, the most iron in a 10-hour variation of 4128 mg/L with 100% extraction percentage, and the most cobalt in a 2-hour variation. as much as 47.3 mg/L with 100% extraction percentage. The highest nickel yield was produced at a 10-hour concentration variation of 87.37%. The compounds produced from the crystallization products were NiSO 4. 6H 2 O, Na 2 SO 4, CoSO 4, and FeSO 4.