Consumer Reports Retesting MacBook Pro Battery Life After Apple Says Safari Bug to Blame

Last month, the new MacBook Pro did not receive a purchase recommendation from Consumer Reports due to battery life issues that it encountered during testing. Apple subsequently said it was working with Consumer Reports to understand the results, which it noted do not match its "extensive lab tests or field data."

2016_macbook_pro_lineup
Apple has since learned that Consumer Reports was using a "hidden Safari setting" which trigged an "obscure and intermittent bug reloading icons" that led to inconsistent battery life results. With "normal user settings" enabled, Consumer Reports said it "consistently" achieved expected battery life.

Apple's full statement was shared with MacRumors:

"We appreciate the opportunity to work with Consumer Reports over the holidays to understand their battery test results," Apple told MacRumors. "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. Their use of this developer setting also triggered an obscure and intermittent bug reloading icons which created inconsistent results in their lab. After we asked Consumer Reports to run the same test using normal user settings, they told us their MacBook Pro systems consistently delivered the expected battery life. We have also fixed the bug uncovered in this test. This is the best pro notebook we’ve ever made, we respect Consumer Reports and we’re glad they decided to revisit their findings on the MacBook Pro."

Apple said it has fixed the Safari bug in the latest macOS Sierra beta seeded to developers and public testers this week.


Consumer Reports has issued its own statement on the matter to explain why it turns off Safari caching during its testing and other details:

We also turn off the local caching of web pages. In our tests, we want the computer to load each web page as if it were new content from the internet, rather than resurrecting the data from its local drive. This allows us to collect consistent results across the testing of many laptops, and it also puts batteries through a tougher workout.

According to Apple, this last part of our testing is what triggered a bug in the company’s Safari browser. Indeed, when we turned the caching function back on as part of the research we did after publishing our initial findings, the three MacBooks we’d originally tested had consistently high battery life results.

The non-profit organization also acknowledged user reports of poor battery life that have surfaced over the past three months.

Consumer Reports said it will complete its retesting of MacBook Pro battery life and report back with its update and findings when finished.

Apple advertises that the latest MacBook Pro models get up to 10 hours of battery life on a single charge when watching iTunes movies or browsing the web. This estimate can be affected by several factors, such as screen brightness, which applications are running, and other system processes.

Related Roundup: MacBook Pro

Top Rated Comments

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50 months ago
The classic Apple "You were testing it wrong" ploy
Score: 92 Votes (Like | Disagree)
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50 months ago

The classic Apple "You were testing it wrong" ploy

I don't think they said that at all. They said the results that CR saw shouldn't be usual based on the way they were running Safari, but they still said they found a bug that they have sense squashed.

They can say that the testing setting they used wasn't common, be right and still admit that there was a bug that needed to be fixed without trying to pass the buck. Problem found, problem resolved.....I don't really see the need to jump up and down on anyone here.
Score: 47 Votes (Like | Disagree)
Avatar
50 months ago
Clearly not a Pro machine if you are required to use Safari to get best battery life.
The older MBP laptops could use any browser, or amazingly it it could run Pro tools like Adobe products without killing the battery. Apple, if you say it has up to 10 hours for a Pro laptop, then we expect around 8 or 9, not 2 or 3. Safari is no excuse.

EDIT: Could we stop ranting about how Chrome is better. I'm just trying to point out that Apple is no longer designing this laptop to have good power for Pro software like Adobe products. Chrome I would not consider a Pro product.
Score: 41 Votes (Like | Disagree)
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50 months ago
It still doesn't fix the problem with the 2016 model having 1/3 smaller battery than the 2015 model.
Score: 35 Votes (Like | Disagree)
Avatar
50 months ago
Killer machine.

But 3 hours battery life when using one music pro application, for the princely sum of £3.5k?

Is it April fools ?

This fix does nothing. The battery is too small. End of story.

Love Apple but currently our relationship is taking a time out.
Score: 34 Votes (Like | Disagree)
Avatar
50 months ago
I'd say CR was testing it right - browsing the internet means loading new pages over the network all the time, not loading a cached page (or pages) over and over again.
Score: 32 Votes (Like | Disagree)

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