Min three slow C/10 Just charge overnite 14 to 16hrs at C/10 then run car until see any sign of slowing do not run dead then recharge over nite after three times good to go to 1C but I myself only charge at 80% of 1C with 4 to 6 mV delta peak lowest I can get away with. After 20 or soo fast charges reform at C/10 for 14 hrs,,, remember formation starts with a empty battery for 14 hrs.
Rich