Weird issue. Tonight I noticed that, despite having plugged it in quite a while ago, the little system tray indicator still suggested I had very low battery charge remaining. Hovering over it revealed something even more troubling:
Next to the available charge was the ominous phrase: “plugged in, not charging”.
Well, that doesn’t sound good!
My first thought when I saw this was, “Well, shit — I’m in the middle of a business trip, I can’t afford for this laptop to die on my now!” And my second thought was, “Well, shit — I’m going to have to either buy a new battery, or a new charging cable, or worse still a whole new laptop, none of which I can afford after my wife spent the last week camped out at the Mall of America!!”
So I began Googling solutions, which ranged from uninstalling and reinstalling the Microsoft ACPI driver for the battery, to replacing the cable and/or battery, to even suggestions that the charging circuit board has to be replaced. The simplest solution, however, was to re-seat the battery. And, being a fan of simple, I tried that.
I did, however, notice in doing so that the battery was hot. Really, really hot. Memories of the time I thought my cable had died, when in fact the thing had just overheated and shut down to prevent itself dying because I had carelessly tossed a heavy blanket on top of it, came back, and I realized that sitting on the bed in my hotel room as it was was really, really bad for air flow from the computer.
So I grabbed a nearby box and propped the computer up on that, and BAM! Not two minutes later the charging LED on the front came on again, and Windows now happily reports “plugged in, charging” next to a pleasantly rising available charge. Hoorah!
TL;DR: Heat is bad. If your laptop is reporting that it’s “plugged in, not charging”, first check if you’re blocking airflow and, if so, let it breath again!
Note: This happened to me on a three-and-a-half-year-old HP G70 laptop, however I wouldn’t be the least bit surprised if other laptops could suffer the same issue. In any case it’s a simple, no-risk possibility you can try if you happen to see the same “plugged in, not charging” message on your laptop.