I hope you're right, xandros9..
My Lumia 635 on Boost Mobile w/ WinPho 8.1 has been telling me "Time since last charge: 0 minutes" for a few days now. I've charged it to full a few times. I've definitely rebooted the phone at least once. I might have done a cold power off as well.
It's definitely a bug, though.. I hope this issue isn't present in Windows Phone 10.