Hello, I just got a brand new Macbook for Christmas. Lately it has been showing a black "X" in the battery bar. It started off by switching back and forth very quickly from the "X" to the correct percentage, back and forth, back and forth. But now, it doesnt even work without the power adapter hooked up to it. Unless I am at 100%, then I can take the power adapter out until it reaches about 70% and starts sleeping when im in the middle of doing stuff on it. And at about 50% it will just completely sleep so you can't wake it unless the power adapter is attached. My Macbook has basically become a desktop =[ Any help would be greatly appreciated Thank You!!