Apple released the MacBook Air SMC firmware update 1.2, compatibility mode has been introduced through the Mac OS X's Software Update mechanism. According to Apple's documentation, "This is an increase of SMC firmware update for the latest compatibility battery replacement service after the successful completion of this update, your SMC Version will be: 1.23f20 [the original model of the MacBook Air or] 1.34f8 [for the latest model].

Under normal circumstances, SMC Firmware Update the system management controller of the Intel-based Mac machines. Council of the control power and cooling management features, including batteries and fans. In this case, the new replacement battery, Apple is clearly different enough that they need to use the latest version of the SMC firmware.