Only six hours of battery life on my 2013 MacBook Air 13"

oh - and i fully agree if the power changes a lot just cause you slept and woke the machine that could be some other bug compounding any affects of backlight

I'm not sayin your 6hrs is caused by running the backlight max. Something is going on and I hope Apple can help.

50wh / 6hr = 8.3W ave

assume 12click vs 14 clicks ~ 0.75W

50wh / (8.3w+0.75w) = 5.5hr , vs 6 hr

at a higher load, the minutes lost per click sensitivity is much reduced. in this case about one click = 15minutes.

So yes you are correct in that the time sensitivity is much reduced at a higher load - and you'd see a smaller effect as you mentioned.

The battery life curve is hours = capacity/watts , or a 1/x curve. At light loads a change 1W power gives a big swing in batetry life. At a higher load the same 1W power gives a smaller effect.

I know this doesn't help you. I don't seem to have the problem you do so I can't offer any remedy.

I'm just saying Apple claim of 12hr @ 12 clicks reduces to 8.8hrs @ 16clicks to point out how much it can change. @ 6hr rate , if occured at 12 clicks of backlight, would be a 5.1hr @ 16clicks - a much lesser sensitivity.

I'm getting about 12hrs @ 12 clicks web browsing myself with a bit of video.but it is light browsing and i don't have any other application open. haven't noticed a change across sleep but i'll be on the lookout now that i've read this thread.

I'm getting about 12hrs @ 12 clicks ....

and i mean i tested this this weekend , from about 10am to 10pm - with some idle breaks. i don't mean that that's what the indicator said.

I have I5 , but i don't think I5 to I7 should be that much of a difference.

I understand where you are coming from with the maths to the equation.I would also agree that changing the brightness does in fact play a major factor. This will apply to any chipset.

I have both the screen brightness and keyboard set at 50%, 8 clicks.

I am actually ok with these settings, its bright enough for me most of the time, but maybe not for others.

The battery indicator changes all the time. I have purposely been using very little today, other than emails, Internet and watching a movie stored on the SSD. I have disabled dropbox and screensaver, as it stands now I am showing 71% battery, 9;04 hours remaining. This is an improvement on what it was showing earlier today

Screenshot showing 100% battery

Screenshot showing 71% battery

It appears that in the world of the new MBA, less is more! 😉

I have the same problem with my i5 128GBSSD 8GB RAM Macbook Air.

Now I have had alot more battery lifetime since I´ve turned down the brightness to 4 spots (way to low for average use). My computer has been running about 5 hours now with 19 % remaining. Not accepteble tough.

yep! I'm not going to defend Apple's estimator but your screenshoots suggest the following:

50Wh / 8.95h (est) = 5.6W - so whatever the computer is doing at the moment you took that screen shot it thinks it is averaging 5.6W.

71%*50Wh / 9.07h = 3.9W - so whatever the computer is doing at the moment you took that screen shot it thinks it is averaging 3.9W.

So the system isn't doing the same thing in both cases - even if from your standpoint you aren't running anything different.

For Lyspaere: If it depleted 81% of 50Wh and you only got 5hr then the average consumption suggests 81%*50Wh/5h = 8.1W of consumption.

The estimator just says " if you do what you been doing for the last few minutes, then I predict this is what's left"

If you go to the About THis Mac / Power section and multiply the voltage times the current it also shows the average power at the moment (might need to cmd-R refresh the reading). I thnk the reading updates every minute or so, so there is some averaging. Meaning if you calculate whats going on with these different methods it might not exactly come out the same, but should be close.

But I agree! - All this math doesn't matter - cause what matters is to figure out what's going on to vary consumption so much if from your point of view you thnk the computer is doing the same thing in both cases.

That's where activity monitor might help.**

The ambient light sensor that varies brightness with display actually throws a monkey wrench into the mix - if the room is dim enough to alter the brighntess.

They said Mavericks is supposed to manage background tasks better so that things that might not be important in the background don't take away from what your doing at the moment. time will tell!

some people are getting great results

http://thenextweb.com/apple/2013/06/30/we-asked-8-new-macbook-air-owners-how-the -extended-battery-has-impacted-their-life-heres-what-they-said/

and as people install their own things from third parties who don't pay attention to how they code, things can go bad:

http://www.geek.com/apple/using-dropbox-cuts-13-inch-macbook-air-battery-life-fr om-12-to-3-hours-1560991/

** actually activity monitor itself takes power to update - so it changes the story when you launch it. But since activity monitor lists processes it really isn't that helpful cause sometimes the process hogs aren't recognizable as applications. I have no idea what some of those processes are and i can't exacty be expected to go kill it cause who knows what it might do. I wish there were an activity monitor that would resolve what application was calling the offending process(es) to give me a better clue

Hi all, for those of you that suspect Dropbox is the culprit, it was for me too. As reported here:

http://blog.nicoschuele.com/?p=151

I was only getting 3 hours of battery life on an i7 2013. Now am getting 7.5 with 70% batt left.

Good news is that if you goto the bottom of the post, there's a solution. You just need to upgrade to the latest stable version of dropbox - for whatever reason its not on their download site (I got a version from April when I installed it earlier this week).

You can find the release notes here:https://www.dropbox.com/release_notes

Latest stable version forum post here:https://forums.dropbox.com/topic.php?id=102563

MacOS download here: https://dl-web.dropbox.com/u/17/Dropbox%202.2.9.dmg

Good luck!

Ok, so yesterday for some reason things seemed better.

I left my MBA charging overnight, got to work at 9am, I used it all day, Internet, emails, word docs, pdfs and watched about 2 hours of locally stored video in VLC, I left the office at 5pm, drove home, turned it on again and I still had an indicated 42% left.

Throughout the course of the day and after I got home, I finally managed 10 hours and 20 minutes before it died.

My screen brightness is set at 50%, I had the keyboard backlight off for 8 hours, and I disabled Dropbox completely.

My main use was as stated above, with the addition of transferring 12GB of data onto an external drive along with downloading some files for approximately an hour.

Overall the battery lasted well.

Now I left it charging for at least 6 hours after the light turned green (whilst sleeping), I am unsure as to whether this is what made the difference, only time will tell.

I too am seeing very low battery remaining times when waking my 2013 MBA. After being on the charger all day it showed only 6:32 of battery time remaining with a 100% charge. I did a restart and suddenly had 15 hours remaining at the same 100% charge. I need to see how many hours I can actually get as I've never really paid that much attention.

Well i have exakt the same battery life problem as mentioned above with my i7/8GB/128GB. Something with the i7 is eating battery and when i spoke to apple sweden when i bought my computer I specificly asked if the i7 will be affecting battery life, the answer was yes but most likely 30min to 1h less battery life. Not like 3-4h less...

I hope that Apple is working on a fix, mabey they can fix it within the software?

I also have this battery life problem.

I have MBA 13 with i7 / 8 / 256

even after full charge (overnight) I never get my battery indicator saying more than 6:30 hrs. (max 7) with 100 %.

And actually I get around 5 hrs.

I tried the solutions provided by Apple care on chat (resetting SMC,PRAM,NVRAM) and after doing that I got battery life of 12 hrs in indiactor and around 8-9 hours actual. but the after the first time the issue was back and still I dont get battery life more than 6 -7 hours in indiactor (actual even less)

My usage is pretty normal including surfing ,youtube and reading pdfs.

I dont understand what is causing the issue.

After my experience with MBA, I don't think there's anything "causing the issue". It's just MBA spec, it never gets close to 12 hours when using web.

Just thought I'd add my experience to the mix as I was also concerned about bettery performance.

I have an i7, 8gb, 512GB.

When new, I experience similarly poor battery life and rather wild fluctuations in the "estimated time remaining". Working as normal, I was lucky to be getting 5 or 6 hours with Word, Excel, multiple browsers, flash video, dropbox, email clients, calendars etc. Discharged the battery and recharged to no apparent avail.

Yesterday however, I discharged the battery to about 4% and then left it charging overnight. Shut down the computer in the morning, left it for about 30mins and then booted it up and disconnected.

Starting fresh, I shut down drop box, kept screen brightness arounf three quarters, and keyboard backlight on around 4 or 5 blips. The battery performance today has been stella. I worked as normal, Word, Excel, Powerpoint (multiple documents), some statistaical software (R), Firefox and Safari, a little chrome for streaming flash video, pdf viewing etc. Timed it, and have got a good 9hrs + so far, and battery is still at 23%, with estimated time remaining of just over 3hrs (although past experience tells me not to trust this too much as obvioulsy work load is dynamic so these things need to be taken with a pinch of salt (it was telling me about 18hrs shortly after disconnecting this morning!).

If it will last!? No idea, but there seems no reason why, even if you have experienced come pretty dodgy battery performances initially that the i7 chip shouldn't deliver close to, or perhaps even in excess, of the 12hrs with good solid use.

I was using it in work mode - no big downloads, file transfers, movies or intensive flash use. Nor was I streaming music. I did have drop box shut down - although my uderstanding is that it's battery drain has been fixed - however I didn't adapt my workload or web browsing in any other way.

Perhaps a good run down and long charge (or two) are all that's needed? Perhaps a fresh roboot to clear the system at the start of the day helps.........keep an eye on screen brightness and background processes if you don't need them - but no need to be too drastic about it, at least from my experience today......

Long may it last is all I can say - it is damm impressive!

well i got the same mac as you, but with 128gb SSD anda I fully charged my mac and it said 7h. 15minutes later it said 9h30. I think that you just need to wait 🙂

Just try it on your own instead of looking at the counter. I'm shocked how many people here judge the battery by looking at this random numbers. When doing standard web browsing, MBA 2013 lasts 7 hours. The counter can even tell you "million hours" or "eternity", but that's the fact.