Disappointed at the lack of responses on this. Turns out it was not battery related OR hardware, but windows - surprise, surprise.
Running Ubuntu everything worked fine straight away, a reinstall of windows then fixed the problem. I gues it was just that time!
Most who respond seem to have experieince with the problem; it may be that your problem was very rare and no one had experieinced it before you did. Glad you solved it. Now when a similar thread is posted you can share your experience!