10 - 30 minutes
Old battery wasn't holding charge.
super simple. watched a video on the ifixit site and changed the battery myself in 5 min. all good.
someone pls convince apple to stop allowing us to update software on old computers...
P5 Pentalobe Screwdriver Retina MacBook Pro and Air
MacBook Air 13" (Mid 2010 to 2017) Replacement Battery