Guys, I replaced my battery with a "alternative" one and every time the battery goes flat the MacBook won't recognize it anymore so it won't charge it. (as describe but everyone here) But if I connect the MagSafe and press Option+Shift+Control+Power for around 10s it will work! MagSafe light goes green then red and battery starts to charge. I am not sure about the correct sequence so try: - Press the buttons and connect the MagSafe. - Connect the MagSafe and Press the buttons . - Connect the MagSafe, wait a bit and Press the buttons . Cheers