I have an acer aspire aoa150 and the battery wont charge. Windows Xp, puts a red X over it . I have tried every thing, from updating the bios to a clean windows install. The orignal battery was about 4 years old so it was about gone. I bought a new battery and used it a few days and I turned it off at 50% battery level when I was done and went to turn it on the next day and it would only turn on on the mains. What do I do to fix it?