Apple has dedcided to put in place a simple, reproducible procedure via a program which will judge the quality of the battery.
The software can be installed on a hard drive or a USB thumb drive, and launches in EFI mode. It proceeds to test the battery and give its result in a graphical form. As long as the battery is in the green zone, it is considered good. The yellow zone corresponds to a battery close to the end of its normal life and the red is when there is a problem. In this last case, a return number is giving, allowing the exchange to proceed under warranty.
Whether or not this puts to rest the randomness in this process, this software will certainly tighten the exchange rules, which is certainly Apple's goal.
Of course, only Apple Authorised Service Providers will officially have access to this software.
