The 15w fast charge is about half an hour faster than the ordinary charge. The 15W fast charge is currently in the second-to-last charging level, and only 10W is currently less than 15W. Up there are 18w, 20w, 30w, 33w, 50w, 60w, 65w, 66w, 67w, 68w, 90w, 120w and 150w, 165w next year.