hard reset (hold home button and sleep/wake till it reboots)
or
drain till it turns off and recharge full (do not take it off of the charger until it's there)
or
Do a factory reset.
Once those 3 things are done, if it still happens, take it in.
Tried the reset. Next resort is a full drain and recharge.
I have read literally dozens of others stating the same, and even worse, issue with the battery read on the Apple forums...it's definitely a new issue.