Hello I have never powered down myself therefor I cannot say for sure but if I understand when you power down it will take a total of 13 weeks and each week you power down 1/13th of your steem power will be taken away from your steem power wallet and the 1/13th will then be added to the steem you have in your steem wallet .
I hope this helps
RE: WEEKLY POWER DOWNS THIS PAST WEEK / ALL MY POWER DOWN CHARTS for the week ON ONE POST