Inspiron 15 battery charge indicator issue

The battery indicator icon continually shows battery at 5%, even while charging (and yes, power adapter light is on and it's the one that came with the laptop).  This is sudden - it was working fine the day before yesterday, and I haven't had battery life slowdowns or other issues.  The system may have installed an update of some sort yesterday.  Plus, when I go to settings and look at the battery, it shows it at 100% when plugged in, and 99% when I unplug it?