if you use a different charger and it does not work then there's nothing wrong with the battery(that's if it worked ok before with win vista), the power config for the battery is different for the win 7 which you installed, use a different win 7 or go to the pc support site and look if they have a software related to the battery/power setup, if they do download it, right click the soft and go to properties and change the compatibility to win vista(laptop originally work with that) the run as admin, this should fix your prob, if they don't have the power related soft then you need to change the windows or if your tech savy you can mod the win config files.
MY OWN HOUSE, CAR AND BUSINESS, LOVELY WIFE AND KIDS