No, they take the same amount of time to charge but they have different amounts of power and different speeds. Fast charge generally charges the phone, and it can charge 50 to 70 percent of the electricity every half hour. The slow charge takes two or three hours to reach 50 percent. The principle is different. Fast charge is to increase the current to achieve a rapid charge to the mobile phone, slow charge is ordinary charging, small flow to the mobile phone fully charged.