|When you plug the charger in does the battery charge? do you see a RED light when charging?|
I have recently 'fixed' a Toshiba laptop with similar symptoms, basically the charger was at fault, it wasnt charging the battery. so therefore you'd assume the battery is fully charged when in actual fact it is empty.
But from doing some reaseach online, i found that Toshiba have issues, basically the hole in which you plug the charger tend to break away from the motherboard, from what i read online, and this is common. so i would look into that as well.
from what i read oneline it could be:
1) The Battery
2) The charger
3) The charging hole (the nut as it was described) breaking away from the board
i would try 1 and 2 then taking it to a repair shop if this doesnt work.