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View Full Version : New Mac air 11/8/i7 only lasted 3 hours




nariza7
Jul 8, 2013, 05:03 PM
So I just received my mac air today and it came charged at 90%. I then charged it to 100% and then let it charge an extra 30 min. When unplugged it from the charger, it lasted only 3 hours (from 100% to 10%) . During this time, I played about 20 minutes of awesomenauts, 10 minutes of tf2, and later I was installing some small apps such as audacity, sugarsynx, evernote, textwrangler, dropbox, etc. I also did light surfing with chrome when I was not installing applications. Is this normal for the first time use? For the last 35%, I played a movie to drain the battery, and it lasted I plan to charged it up to 100% again to see if the battery still drains quickly.



simsaladimbamba
Jul 8, 2013, 05:06 PM
Playing games is CPU intensive and depending on the brightness level your battery time seems correct.

______________________________________________________
This should answer most, if not all, of your battery questions:
Apple Notebook Battery FAQ (http://forums.macrumors.com/showpost.php?p=9875442&postcount=23) by GGJstudios (http://forums.macrumors.com/member.php?u=186377)
The F.A.Q. includes the following topics:

BATTERY INFORMATION
BATTERY LIFE FROM A CHARGE
AC POWER
CALIBRATION
BATTERY LIFESPAN
CHECKING STATUS AND HEALTH
CHARGING
WHAT IS A CYCLE?
BATTERIES ARE NOT COVERED
BULGING OR SWELLING BATTERY


______________________________________________________

nariza7
Jul 8, 2013, 05:32 PM
I've only played for like 30 min total though. I thought I read somewhere that it could last 4 hours constantly playing a pc game. I guess ill charge it to 100 again and see how well it does. If it can't last 5 hours, im going to applestore to get it checked

alexrmc92
Jul 8, 2013, 05:44 PM
I've only played for like 30 min total though. I thought I read somewhere that it could last 4 hours constantly playing a pc game. I guess ill charge it to 100 again and see how well it does. If it can't last 5 hours, im going to applestore to get it checked

it only gets 9 hours when using nothing but basic web browsing in safari. i get about 2 hours when constantly gaming on my i5/4/256 13". Considering you have a smaller battery and a slightly more power consuming processor, it doesn't seem too far off.

simsaladimbamba
Jul 8, 2013, 05:47 PM
I've only played for like 30 min total though. I thought I read somewhere that it could last 4 hours constantly playing a pc game. I guess ill charge it to 100 again and see how well it does. If it can't last 5 hours, im going to applestore to get it checked

Read the FAQ I linked to in order to find out, what determines battery life. Brightness is important too, as is Bluetooth and WiFi and some other factors.

joewillmott
Jul 8, 2013, 05:48 PM
3 hours doing what you mentioned sounds right to me. The 11" doesn't have the battery life of the 13" and it sounds like you were doing a hell of a lot of stuff. Games get pretty much every part of a laptop going and since a MBA isn't made for games it really has to give its' all. Downloading and installing so many programs would also be giving it decent usage and then watching something on it is not just putting the laptop through the work of showing it, but also downloading as you play. Mixed in with keyboard backlighting, screen-lighting and anything going on in the background, 3 hours is impressive to say the least!

You could always download something like activity monitor to check your battery health and see when your computer is struggling to handle the tasks you're throwing at it.

TC25
Jul 8, 2013, 06:41 PM
I thought I read somewhere that it could last 4 hours constantly playing a pc game.
You read wrong.

I guess ill charge it to 100 again and see how well it does. If it can't last 5 hours, im going to applestore to get it checked
If the store is smart, they will give you your money back and suggest you go to Best Buy and purchase a Windows machine. An MBA is not a gamers laptop.

nariza7
Jul 8, 2013, 07:30 PM
Oh, I don't plan on using it for gaming. I don't have the patience for it on this. I wasn't too worried with the drain from gaming. After I stopped playing, it went from 1.5 hrs to like 4.5 hours left on the estimate so it seemed okay since it was the first cycle.

Unfortunately, the mac air only lasted like 1.5 hours after gaming. The 30-40% drain from the next hour is what bothered me. I pretty much just installed around 10 basic apps(like coconutbattery, chrome, vlc, mplayerx, evernote, sugarsync, audacity, etc.) kept 3-4 tabs in chrome opened for this macrumors forum/downloads and 1 tab for gmail, and sorted some files through my old computer. I just left my mac air awake while I was sorting the files on another computer though so I didn't do much with it. I did have bluetooth on for the mouse since I used that to keep the mac air awake. Does that drain a lot of battery too?

The last 35% was just me trying to see how well it handles videos. a 25% drain in like 40-50 minutes of a 720p movie sounds okay right?

I'll give it a few more cycles to see if it improves. Maybe I'll do the battery calibration mentioned in the earlier link. I just wonder what kind of tasks others have done to achieve 5+ hours.

Maybe I had extra tasks running in the background that were contributing to the battery drain.

jasonbrent
Jul 8, 2013, 07:40 PM
... in the not to distant future I'm gonna have an app to track what's going on here and remove the human component in this type of concern.... I'm in the process of writing it...


batteryServices() called at Mon Jul 8 20:34:17 2013
Mon Jul 8 20:34:17 2013 -> currently draining at -2362 mAh [6981 of 7150 max: 7320] (Charged)
-> lastFullCharge: (1013.00s ago) Mon Jul 8 20:17:24 2013
-> lastOnPower: (1013.00s ago) Mon Jul 8 20:17:24 2013
-> lastCharging: (1373330057.00s ago) Wed Dec 31 19:00:00 1969


I intend to keep track of top CPU consumers by draw when not on power to know what's really training.... In the example above, I'm purposefully trying to drain the battery using Diablo 3.

Also, when your mac says it's fully charged to 100%.. and when the light is green.. it is *NOT* fully charged... 20-30 minutes AFTER it says it's fully charged is it actually fully charged. Basically, MacOS reports charged and 100% capacity when the battery is actually >= 95% capacity and very slowly charges the last 5%... anyway.

-jbl

throAU
Jul 8, 2013, 08:39 PM
I've only played for like 30 min total though. I thought I read somewhere that it could last 4 hours constantly playing a pc game. I guess ill charge it to 100 again and see how well it does. If it can't last 5 hours, im going to applestore to get it checked

Depends on the game.

You can work out worst case battery life for a laptop by doing:

take the CPU wattage + GPU wattage + other significant power consumers like the screen and add them up. lets call this number A
take the battery capacity in watt/hr, lets call this number B
your worst case power consumption will be pretty close to B/A hours


e.g., macbook air 11"


CPU wattage (no discrete GPU) = 35 watts
battery capacity = 38 watt/hr (B)
screen, ssd, etc = i don't know, but compared to CPU probably not heaps. given teh MBA has a 45 watt PSU (source: apple spec), let's assume the rest of the machine adds up to between 5-10 watts. A = ~40-45 watt



Total max power draw (A) = 45 watt
Worst battery life = B/A = between 38/40 and 38/45 hours
= 0.95 ~ 0.84 hours

or around 50-60 minutes worst case

Now if your game consumes 50% CPU, maybe you'll get 2 hours?


CPU + GPU are by far the biggest consumers and unlikely to be 100% utilized even when pushing the machine hard, so you can approximate the above (to get a very rough, quick idea of potential wost case battery life when working hard) by doing

(CPU power + GPU power) / (battery in watt/hr)

Lunfai
Jul 8, 2013, 08:57 PM
Just to be clear you didn't buy a 2012 MBA by accident ? :')

nariza7
Jul 8, 2013, 09:14 PM
lol that 2012 worry did cross my mind, but I checked and it had haswell and intel 5000. After disconnecting the charger, it says 17+ hours for estimated time. Maybe it's okay now. I will see how long it lasts heh.

scaredpoet
Jul 8, 2013, 10:12 PM
Oh, I don't plan on using it for gaming.

Then don't test it the way a gamer would. :) use it the way you intend to use it, and see how long the battery lasts then.

nariza7
Jul 8, 2013, 10:58 PM
Yeah tomorrow I will test it for my usual purposes. Today was focusing on setup, adapting from pc to mac, and checking how good the graphics were. Battery hasn't impressed me yet, but I shall find out tomorrow

TPadden
Jul 9, 2013, 12:20 AM
Yeah tomorrow I will test it for my usual purposes. Today was focusing on setup, adapting from pc to mac, and checking how good the graphics were. Battery hasn't impressed me yet, but I shall find out tomorrow

You were also setting up spotlight/ indexing the new machine, probably without realizing it :).

gabberkooij
Jul 9, 2013, 12:46 AM
Yeah tomorrow I will test it for my usual purposes. Today was focusing on setup, adapting from pc to mac, and checking how good the graphics were. Battery hasn't impressed me yet, but I shall find out tomorrow

There are reports of Dropbox using a lot of CPU cycles, so you might want to disable it for a while.

ringgit
Jul 9, 2013, 04:31 AM
Not that it matters, but Skydrive seems to be doing ok, while Dropbox sucked battery life.