A few weeks ago I let the battery on my laptop run all the way down. Since then it hasn't charged up again when my laptop is plugged in at the mains. I tried removing and putting it back in and booting up with and without it to see if this would 'wake it up' in any way but nothing seemed to help.

Then yesterday, it displayed as fully charged. "Ah great I thought, all sorted." But now it is again showing as 0% charge and I haven't done anything but run the laptop off the mains. The machine isn't very old and I seldom run it off the battery so I don't see how it can be that the battery has died. It's almost like something isn't detecting something properly, but I really don't know...

Any clues?