Last December, Consumer Reports, a long-standing publication known for their unbiased product testing, gave Apple’s latest line of MacBooks a “not recommended” rating. It marked the very first time that a MacBook failed to earn the recommendation from the publication. According to their initial report, while the MacBooks “did very well in measures of display quality and performance”, during their rigorous testing they found that “the models varied dramatically from one trial to another” when it came to battery life.
In one series of three consecutive tests, Consumer Reports found that “the 13-inch model with the Touch Bar ran for 16 hours in the first trial, 12.75 hours in the second, and just 3.75 hours in the third.” Testing on the 13-inch model without the Touch Bar and the 15-inch model yielded similar inconsistent results.
After a bit of public back and forth, Apple and Consumer Reports worked closely together to identify and rectify the battery life issue in all three MacBook models. Eventually, through the somewhat unorthodox methods Consumer Reports uses to test laptop batteries, an “obscure and intermittent” bug existed within the Safari browser that was causing the battery drain. Apple issued a statement several days ago explaining how the bug was uncovered during the testing process.
“We learned that when testing battery life on Mac notebooks, Consumer Reports uses a hidden Safari setting for developing web sites which turns off the browser cache. This is not a setting used by customers and does not reflect real-world usage. [Consumer Reports’] use of this developer setting also triggered an obscure and intermittent bug reloading icons which created inconsistent results in their lab.”
Apple was able to isolate the bug and fix it via a macOS Sierra software update, and Consumer Reports agreed to re-run the tests. After re-testing, they found that “a software update released by Apple on January 9 fixed problems we’d encountered in earlier testing.” The publication now recommends all three MacBook models.
“With the updated software, the three MacBook Pros in our labs all performed well, with one model running 18.75 hours on a charge. We tested each model multiple times using the new software, following the same protocol we apply to hundreds of laptops every year… Now that we’ve factored in the new battery-life measurements, the laptops’ overall scores have risen, and all three machines now fall well within the recommended range in Consumer Reports ratings.”
Although the bug causing the battery drain was fixed with a software update, the update is a beta version of macOS Sierra, and is not yet available to the general public. The bug fix will be rolled out to users in several weeks, included in a full operating system update. Although most users won’t encounter this bug in regular usage, and will likely have no problem waiting for the official update, those eager to get their hands on it can sign up for Apple’s public beta program to run the beta update on their laptops.