But you can fix it!
It would be nice if Apple found its own fix for this idiosyncrasy, but in the meantime, there is a manual workaround to get your battery indicator back to normal. Essentially, you need to recalibrate the battery, which requires very little other than patience.
To begin the process, you’ll need to drain the battery entirely so that it shuts itself off -- go make a crazy-good Snapchat Story or stream a few HD videos and you’ll get there in no time. Then, plug your phone in and let it charge all the way up to 100% without using it. Keep it plugged in an extra hour or two, just to ensure it’s fully charged (patience, people). Next, you’ll perform a “warm restart,” holding down the home and lock buttons simultaneously for a few seconds until the Apple logo appears on the screen. Cool, now do the whole thing over again. More Snapchat! After you repeat the whole process a second time, you should be back in business with an accurate battery indicator once again. Hallelujah.