From a Electrical Engineering standpoint, any battery of tests will not hold up due to the amount of variables, both software and hardware. The article references iPhone as a perfect case, but Apple (and AT&T, indirectly) have 100% control on what occurs on the device. The software, hardware, and user flow is under strict standards of processing and memory allocation. Furthermore, the low processing power and subsequent need makes the margin-of-error and standard deviation lower.

This is not the case for laptops. Due to running different programs, there are differing memory and processing allocations which cause different hardware elements to be accessed. Chrome and Firefox (same use case) have vastly different memory footprints and certain versions of Photoshop (same program) will utilize the GPU, increasing current drain. Since programs are constantly under development and will use different amounts of resources, a manufacturer cannot say that browsing the internet or using a specific program will be a certain amount of time.

Mainstream laptop batteries are Lithium-Ion, which degrades with time (faster with use). Unless retailers begin to throw out older batteries (by manufacturing date), there will be no standardization for consumers.