Yesterday I replaced my HDD of my MacBook Pro 2011 with a SDD. After I unhooked the battery connector and replaced the HDD with the SSD, hooked the battery up again and installed mountain lion from a bootable disk my MBP gave me the no batteries available warning. After trying everything possible from reattaching the battery to pram zapping and putting the HDD back in I tried the SMC mode. After entering the SMC mode and restarting it in SMC mode it runs without AC power just fine so the battery ain't dead. The connector is fine because else the battery won't transfer power. Once your out of SMC mode it will only run on AC power. So I've tried it all and came to the conclusion that the battery is fine but it won't get detected by the computer. Does anyone know a solution?