How long does it take to fully charge PIE? Bagel Labs August 07, 2018 08:43 Updated Follow PIE takes around 2 hours to fully charge with an average 5V DC adapter and the included micro USB charging cable. Related articles How long does the battery last? My measurements all show up as 0 on iOS I am getting different results whenever I take waist circumference measurements. Why is that? Comments 0 comments Please sign in to leave a comment.