Tuesday, December 13, 2016

macOS 10.12.2 Removes Battery Time Remaining Estimate

Jim Dalrymple (MacRumors, Hacker News, 9to5Mac, Slashdot):

Some users have reported problems with battery life, but Apple told me that after a lot of testing they stand behind the 10 hour battery life with the new MacBook Pro.

However, to help users better determine the battery life, Apple has removed the “time remaining” indicator from the battery icon in the menu bar with the latest update. You can still see the image on the top of the screen, and you can see the percentage, but you will no longer be able to see how much time is remaining before your battery dies.

The reason for removing it is very simple: it wasn’t accurate.

John Gruber:

This is like being late for work and fixing it by breaking your watch.

Benjamin Mayo:

My personal experience is that this estimate was always widely inaccurate on every MacBook I’ve owned. It would change erratically and jump from seven hours to three hours on a whim, based on whatever intensive task was just opened. Its removal doesn’t come as a hindrance, therefore, because I was never really basing my computer usage around what that readout said. Some Windows manufacturers have already removed battery time estimates from their PC laptops.

The new update makes the Mac mirror how iOS has always worked[…]

I tend to think that an inaccurate (but constantly updating) estimate is better than none. Otherwise, people will have to make their own estimates, which takes attention and is likely to be even less accurate. I never liked how the estimate claimed to be accurate down to the minute. I would like to see an estimate with fewer significant digits, both to hide the erratic changes and to avoid over-representing the accuracy.

Secondly, would this have even become an issue if Apple hadn’t made the new MacBook Pro’s battery smaller? This smells like a software bandaid for a hardware problem, like when they responded to antenna problems by making the iPhone signal strength bars taller.

Update (2016-12-13): Marco Arment:

My 15-inch 2016 MacBook Pro with Touch Bar is pretty good in most ways, but it’s a noticeable regression in battery life from the previous generation. Apple claims it lasts 10 hours, but I’ve never gotten that — in a fairly light web-productivity workload, I average around 5–7 hours, and if I’m using Xcode, I’m lucky to get 4–5 hours.


Having used Apple laptops for over a decade, I’ve always found the time-remaining estimate to also be a good indicator of how much power I’m burning with my current activities so I can “budget” my battery usage when I’m going to need it.


A percentage only tells you the current state, not the rate of change — it would take much longer to notice an unexpected power drain from the percentage alone.

Mike Flegel:

“Mileage estimates in a Tesla depend on a lot of factors, so we’re going to get rid of Distance-to-Empty. You’re welcome.”

Update (2016-12-14): John Gruber:

I know iOS has never had a time remaining estimate. That’s fine for iOS. I think it’s useful on MacBooks, especially just as a loose estimate.


On iOS, the battery % indicator is not a battery % indicator. It’s a time remaining, converted to % with some fudge factors.

This is why on iOS you can sometimes see the battery % go up after you exit a power hungry app.

There is more information about that here and here.

Update (2016-12-15): You can still get time remaining estimates using Activity Monitor, iStat Menus, Outlet, and pmset.

Update (2016-12-27): Kaspars Dambis (via Hacker News):

Assuming that macOS is pulling the battery estimates from the TI chip (see pages 16 and 17 of the datasheet for all the available data fields) it is possible that the algorithms used by the chip don’t account for certain power usage behaviours of various components (for example, power saving modes) which produced wildly inaccurate estimates.


Here is a great paper on the internals of the MacBook battery by Charlie Miller and a video of his talk at DEFCON 2013 on the same subject[…]

Update (2020-01-24): Nick Heer:

A weird and also horrible thing about using MacOS these days is having to open the Energy panel in Activity Monitor to see how much time you have left on battery.

Update (2020-04-20): Tanner Bennett:

BetterTouchTool has a battery widget for the Touch Bar which can display time remaining.

7 Comments RSS · Twitter

[…] Removing a primary indicator of battery life and saying that it’s a means to “help users better determine the battery life” is, frankly, hilarious. Michael Tsai: […]

"Secondly, would this have even become an issue if Apple hadn’t made the new MacBook Pro’s battery smaller? This smells like a software bandaid for a hardware problem, like when they responded to antenna problems by making the iPhone signal strength bars taller."

So, everyone who buys a Mac gets a free rubber bumper?

Personally speaking, a minimum time remaining estimate would be:
1) more useful than having *no* time remaining estimate
2) it would be by definition very easy to predict (capacity remaining / max burn rate)

>I know iOS has never had a time remaining estimate. That’s fine for iOS.

No, it's not.

4-6 hours is pretty abysmal for what are ultrabooks in all but name. And that's on light use, if using the Pros for their namesake with video and photo editing and so on, expect maybe 3.

Now imagine if we had this years components with last years battery size, which was a full 25% larger. For a mere 3.5mm more thicnkess, I think most of us would have chosen that.

If Apple says the batteries are performing like normal I guess this hardware is beyond fixing, and it's up to future procesor updates to deal with it.

A reasonable fix would be to use running averages with samples spread over several minutes (top does this because system load varies wildly over time). I don't know how it was working, maybe it already did that (I didn't work in macOS division when I worked at Apple). And wasn't macOS redesigned the past several major versions to reduce overall CPU use anyway? So why is CPU use so wildly out of control in general and on new MacBooks specifically all of a sudden? Point is there are ways to smooth out lots of data points that change over time to build an overall trend.

Removing it completely smacks of Business decided to cover up a real issue design decisions that to make a thinner/lower volume laptop came at the expense of battery life (and more RAM). The laptops are not iOS consumer devices, they should be a higher level product and thus perform at a higher level.

[…] macOS 10.12.2 Removes Battery Time Remaining Estimate, New MacBook Pros and the State of the […]

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