I have a 13" unibody Macbook Pro. For some reason the fan died so I decided to replace it on my own since it was out of warranty. While replacing the fan I decided to unplug the battery as well, just as a precaution. Everything went fine (I though) but when I tried to turn it back on it wouldn't turn on until I plugged in the power adapter. Once it booted up, the battery display had a big X in it, and it said "No batteries available". I tried resetting the SMC and PRAM, but neither fixed the problem. When it was booting up from the SMC reset the battery indicator changed to "charging" for a second and then went back to the X. Anything I could find just said to reset the SMC and clean the battery connections, beyond that I have no idea what to do. Is my battery suddenly dead for some reason? Any ideas on what I could do? This is my first post, but I would really appreciate any help. Thanks to everyone on the forum.