There seem to be many forums inquiring as to why laptop batteries are not charging. Well there is at least one legit reason for this. Microsoft has designed the power management in Windows Vista to extend battery life.
The way this is done is through a setting which details when the computer actually starts charging the battery. This is done through the advanced battery settings. You can change when your battery starts charging as well as at what point it stops charging.
Still many users are experiencing legitimate issue with power management in Windows Vista. I myself have had this wonderful experience. The computer manufacturer has replaced the motherboard, battery and even the charger, and the battery still remains at 2%.
I cant say as to what may be the cause, but at this point having replaced every piece of hardware trying to resolve the issue, I know it cannot be due to a hardware failure.
I am still in the process of working with the OEM manufacturer on this issue. As soon as a solution is found I will not the cause and resolution. Not to say that my resolution will fix every instance, at least it may help you in finding a starting point.