180 days is my experience from 2 accts. I had that I goofed up on by extra refunding myself from one stealth acct. to another i.e. one penny item I refunded $40 to my other stealth acct.
Yep all my closed accts. have poor feedback, many claims, a 2 z, etc. mainly because I sell best selling items in a major category which has high return rate & newbie customers.