Hi, Let me know if this isn't the right place for this post... new to here, just seems like a trustworthy forum for troubleshooting my problem. A few days ago I installed an SSD in the main drive bay and the original HDD into a data doubler in the opti-bay into my Early 2011 MacBook Pro (15", 2.3gHz, 8gb OWC ram). The SSD is a 240gb OWC Extreme 6G, while the original HD is a 750GB Toshiba. As I still need to use 10.6.8 for some things, I decided to keep that on the original HDD, and install Mavericks on the SSD. I created a bootable Mavericks USB, and the install seemed to go pretty seamlessly and when I was inside Mavericks it all seemed very fast and stable. However, maybe an hour into me installing apps and making it how I wanted it etc (Google Chrome, wallpaper change, mouse settings, etc) I noticed that there's an 'X' on the battery icon and it indicates 'No Battery Available'. Possibly related or possibly not, I replaced the battery fairly recently with a 'refurbished' genuine Apple battery from MacFixIt. Along with this, kernal_task was using all of my CPU and slowing down everything, although that seems to have settled down for now. I followed the install instructions faultlessly for putting in the data double, SSD, etc well so I don't think the fault is there. SO... 'No Battery Available' is still being displayed and the computer powers off if I unplug the MagSafe adaptor. I've reset the PRAM, SMC (power hold method, shft+cntr+optn+power etc) to no avail. Any suggestions at all? There's a couple of threads floating around on the net with people experiencing the same issue, although no solutions that I know of or have found. The one 'solution' which was moving a system file didn't help either (which I promptly put back). I've reversed the mod optical drive back in, SSD and data doubler out no luck. Booted up in Diagnostic mode and the short diagnostic page didn't report any problems, although in hardware list the battery is not listed. I also booted up the laptop with the battery not connected and it operates exactly as if it was connected. The computer is also slow to boot up now, and when I press the power on button the sleep light flashes a couple of times before booting. AND finally, when using Pro Tools 10 on my old HDD, it's giving me a lot more CPU errors than before. Any ideas? The fact that I installed Mavericks, SSD, data doubler etc seems to coincidental for it to be a problem with the battery alone. ANY help whatsoever is appreciated. I have some sessions and lots of work to do on this laptop in the next couple of days, I really thought it was pretty failsafe if I kept 10.6.8 on the other HDD but now I'm not so sure. Thank you!