Apple has released a bunch of firmware updates in order to fix a rare issue which plagued systems which rely on excessively used batteries, where it involved the affected device to be unable to boot up. This bunch of EFI firmware updates should bring an end to systems affected that will sometimes see the unexpected shut down or having the machine simply freeze.
Apple has long determined battery health via the number of charge cycles which said battery has gone through. A solitary charge cycle is a sum of partial charges which equates to one full charge, and has claimed that batteries ought to last anywhere from 300 to 1,000 charge cycles. Needless to say, Murphy has struck as a relatively rare issue in select systems resulted in a non-functional machine whenever the system detects that it has already passed the 1,000 charge cycles mark.
A trio of EFI firmware updates for the MacBook Pro, MacBook Air, and MacBook ought to fix this issue for good, and they can be obtained via the Software Update section, although you can also head towards these links: MacBook SMC Firmware Update 1.5, MacBook Pro SMC Firmware Update 1.6 and MacBook Air SMC Update 1.8 and perform the updates manually yourself.