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Battery life on Yosemite for MBA 2013

g.t. rags said:
thats actually not true....

one of the biggest features when i upgraded to mavericks, was battery life increase. they found a way for safari and mail to use almost 2/3rds the power it was using previously....

i watched my previous MBP go from 3 hours to almost 4 hours of active battery life when i upgraded
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This gets into a kind of hairy discussion about the definition of an operating system... from a computer science standpoint, Safari and Mail are not part of the OS and therefore their power consumption shouldn't factor into the discussion... but from a common sense standpoint they come with the Mavericks "operating system" download so it seems like they must be part of the operating system...

In any case, the core part of the operating system that's running when you don't have any programs "active" in the dock (crude description but hopefully effective) does not have much impact on battery life.
 
motrek said:
This gets into a kind of hairy discussion about the definition of an operating system... from a computer science standpoint, Safari and Mail are not part of the OS and therefore their power consumption shouldn't factor into the discussion... but from a common sense standpoint they come with the Mavericks "operating system" download so it seems like they must be part of the operating system...

In any case, the core part of the operating system that's running when you don't have any programs "active" in the dock (crude description but hopefully effective) does not have much impact on battery life.
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i completely see what your saying, and to slightly add to what you just said, without upgrading to the new OS, you don't get those power saving programs that had been mentioned above...
 
g.t. rags said:
i completely see what your saying, and to slightly add to what you just said, without upgrading to the new OS, you don't get those power saving programs that had been mentioned above...
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That's quite true. However, the energy savings comes from the apps (which not all users will use), not from the OS X version. Those who choose to use Chrome or Firefox or another mail app won't see any noticeable difference in battery life between OS X versions.
 
Hi guys, maybe you can help me. I have the same issue with my MBP and Yosemite. I have a battery life of 1:56 by 85%. No app is using significant energy. In activity monitor is no application with energy impact of more than 6%. Before the upgrade my battery life was more than 5 hours. Battery cycles aprox. 330. Battery status: normal. The reason i changed to apple a couple of years ago was the perfect working system, where me as a user doesn´t need to work around to "optimise" the system to be able to work with. It worked perfectly for this time, but now, this month it was the first time I recollected the times, where I spent hours by tuning my crazy Microsoft crap... Please :/
 
Niktosko said:
Hi guys, maybe you can help me. I have the same issue with my MBP and Yosemite. I have a battery life of 1:56 by 85%.
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Your battery time remaining is a constantly-changing estimate, based on the minute-to-minute workload on your computer. For that reason, it's not very accurate and shouldn't be depended on as a gauge of battery life remaining. A truer test would be to see how long you actually run on battery power before it shuts down.
 
Niktosko said:
Hi guys, maybe you can help me. I have the same issue with my MBP and Yosemite. I have a battery life of 1:56 by 85%. No app is using significant energy. In activity monitor is no application with energy impact of more than 6%. Before the upgrade my battery life was more than 5 hours. Battery cycles aprox. 330. Battery status: normal. The reason i changed to apple a couple of years ago was the perfect working system, where me as a user doesn´t need to work around to "optimise" the system to be able to work with. It worked perfectly for this time, but now, this month it was the first time I recollected the times, where I spent hours by tuning my crazy Microsoft crap... Please :/
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Do not trust Apple's 'Energy impact' estimates. They do not reflect system processes which can sometimes take up a large amount of battery. Instead in activity monitor you want to be looking at the CPU tab and make sure that you select View > All Processes from the menu bar. Then you want to see if there are any processes (not apps, processes) taking up a significant amount of battery life. Spotlight indexing for example can show up here while it won't show up in Apple's energy impact list. mdworker = spotlight btw.

Also if your full battery life is 5hrs then getting 1:56 at 85% due to a temporary spike in cpu usage doesn't sound that abnormal.

I've been using macs since 2009 and I find that keeping track of cpu usage is the best way to get the most out of a battery (lowering display brightness is also key). You would be surprised at the random seemingly easy computer tasks that can peg your cpu (scrolling using the trackpad vs. using arrow keys in chrome for example). If you add Activity monitor to the dock you can right click and make it show cpu history so you won't be scratching your head wondering about battery life the next time it looks abnormally low.
 
I updated my 2013 13" MBA (4GB RAM/ 256GB SSD) to Yosemite about a week after 10.10.4 came out, like two months ago or something, and I have noticed battery life has decreased significantly.

With typical use I could eke out 2 days of use on a single charge, but no longer. Now I'm lucky to get a full day out of a charge, usually it's less.


Hope this will be remedied soon.
 
Since this has been bumped up, I have a question. How accurate is [time] remaining monitor under the battery icon? What I'm looking just can't be true. I just took the laptop off battery to see how battery life is in general.
 
MacBoook160 said:
Since this has been bumped up, I have a question. How accurate is [time] remaining monitor under the battery icon? What I'm looking just can't be true. I just took the laptop off battery to see how battery life is in general.
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It's based on how much power your computer has used in the last minute or so.

If you keep using exactly the same amount of power, the estimate will be pretty accurate. But the odds of that are pretty slim.

The CPU can use anywhere between ~1W and ~15W depending on what you're doing with the laptop. That swing is enough to reduce the 13" model's 12 hour advertised battery life to about 3 hours.

So as you can see, estimating the remaining battery life is a tricky problem.

Not unlike when your car estimates how many miles you can drive on the remaining gas in the tank. You're going to get radically different numbers if you're driving on a flat highway at 50 MPH vs. if you're driving up a steep and windy mountain road.
 
motrek said:
It's based on how much power your computer has used in the last minute or so.

If you keep using exactly the same amount of power, the estimate will be pretty accurate. But the odds of that are pretty slim.

The CPU can use anywhere between ~1W and ~15W depending on what you're doing with the laptop. That swing is enough to reduce the 13" model's 12 hour advertised battery life to about 3 hours.

So as you can see, estimating the remaining battery life is a tricky problem.

Not unlike when your car estimates how many miles you can drive on the remaining gas in the tank. You're going to get radically different numbers if you're driving on a flat highway at 50 MPH vs. if you're driving up a steep and windy mountain road.
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Damnit, motrek, I want answers! :D

The battery has been draining very fast for a new laptop. But, in the last half hour, I've finally taken all my tabs off Chrome and put them on Safari. Chrome is no more. The effect on CPU and Energy Impact on the Activity Monitor has been dramatic already. Same number of tabs open. Now there's a new thing called Window Server and kernel task is still there, but again, the impact is so much lower. And the computer temperature has significantly dropped too. Significantly.

I'm sure if I let this charge down and recharge, then go back on battery power, I'm going to see far better battery results as well, though I still doubt I can get 9 hours. We'll see.
 
I had expected that - but when Chrome was main browser, it overwhelmed the activity monitor to such an extent that I never saw them on the list!
 
It's about the same as it was for Mavericks on my 2013 MBA 11. It seems slightly better with the El Cap beta.
 
zephonic said:
So anyone else still experiencing reduced battery life after the Yosemite upgrade?
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I've never experienced reduced battery life from any OS X updates.

Initially all the updates have done Spotlight reindexing, and that requires a bunch of CPU time and power and will thus reduce your battery life if you are running on battery power.

The time it takes to reindex depends on how much data you have and could be anywhere from 20 minutes to several hours to potentially a few days, I suppose.

After it's done reindexing I can't think of why one version of the OS would take any more or less power than any other version of the OS.

If you look in task manager, you can see that the OS (kernel_task, WindowServer, and a few others) only take a few percent of CPU time.
 
zephonic said:
So anyone else still experiencing reduced battery life after the Yosemite upgrade?
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I feel like I'm getting slightly less battery life (as in 8-9 hours versus the 10-12 I used to get), but I'm not sure if that can be attributed to the aging of the battery. Honestly, this battery has held up much better than any other laptop battery I've had before in my Windows computers.
 
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gmintz09 said:
I feel like I'm getting slightly less battery life (as in 8-9 hours versus the 10-12 I used to get), but I'm not sure if that can be attributed to the aging of the battery. Honestly, this battery has held up much better than any other laptop battery I've had before in my Windows computers.
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You can try apps like "Battery Health" to see the system's estimate of your battery's charge capacity vs. what it was when it was new, to see how it has aged.
 
motrek said:
You can try apps like "Battery Health" to see the system's estimate of your battery's charge capacity vs. what it was when it was new, to see how it has aged.
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Thank you! I just downloaded that app and it says it's still at 96% battery health...so I guess I'm not sure why my battery life has changed as much as it has. It's still not bad at all, but it is noticeably less than when I got it. I don't feel as though my usage has changed much. Hmmm.
 
gmintz09 said:
Thank you! I just downloaded that app and it says it's still at 96% battery health...so I guess I'm not sure why my battery life has changed as much as it has. It's still not bad at all, but it is noticeably less than when I got it. I don't feel as though my usage has changed much. Hmmm.
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You can use Activity Monitor (the CPU tab) to make sure nothing unintended is taking up your CPU time. Maybe the web sites you visit have different ads now that take more CPU power.

Unfortunately I would guess that poorly-coded ads account for a huge percentage of worldwide CPU usage. The amount of pollution and carbon dioxide they must be adding to the atmosphere must be astronomical.
 
zephonic said:
I guess it's just me, then. By my estimation, my battery life has gone from 9-10 hrs to 5-6 hrs.
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No, it's not just you, I've been experiencing the same thing. After upgrading to 10.10.4 it dropped from 11 to 6 hours, roughly, and that's with a brand new MBA 2015. Glad I'm not alone. Less glad it's happening, especially because I had an MBA 2010 and got this one just to have a longer battery life. I'm away right now, with a very slow connection, but I'd rather go back to 10.10 than having this issue. Hope 10.10.5 can fix it, or Santo Domingo, I mean El Capitan.
 
I've found the culprit, at least in my case: notifications! They take up a lot of energy, I had no idea. Previously I tried everything, running diagnostic (everything ok), reinstalling a backup copy, installing a fresh OS, resetting SMC, nothing was working, and no hidden tasks running. Then I ran a MacWorld test: running an HD movie with notifications off, plus other usual settings. And then I ran my usual environment with no notifications, it went from 6.5 hours to 11+ or so. Wow!
 
organic bond said:
I've found the culprit, at least in my case: notifications! They take up a lot of energy, I had no idea. Previously I tried everything, running diagnostic (everything ok), reinstalling a backup copy, installing a fresh OS, resetting SMC, nothing was working, and no hidden tasks running. Then I ran a MacWorld test: running an HD movie with notifications off, plus other usual settings. And then I ran my usual environment with no notifications, it went from 6.5 hours to 11+ or so. Wow!
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how many notifications are you getting on a daily basis?
 
I'm not sure, not that many. In any case I turned off all of them in my test. And now that I know what was causing my battery to drain that fast, I can tune my machine to my needs. Plus I have to correct myself, it's not 11+, it's about 13 hours. Pretty amazing.
 
The fact is that I had 16 apps active in Notification Center, and managing them was taking too much power.
 
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