My battery stopped charging months ago. Won't let me update bios because battery is "zero% - plugged in not charging." Tried every trick online to no avail to kick start it.
For some weird reason, despite the battery not charging and showing "0% full" and the constant "40%" message I hit "retry" about 50 times in the "Windows Update" settings and eventually it updated. Then I sold the piece of junk on eBay "as-is" and bought a new Dell (outlet) XPS-13 for 1/2 the list price on their Memorial Day sale + coupons.