Battery and noise comparison between 11 inch and 13 inch MacBook Air

[ccsicecoke]

Battery

I had a 11 inch air 1.4GHz/4GB/128GB for two weeks. I usually set the brightness to 75% and for consistent web browsing (no heavy flash) I can get about 5h15min battery life. I noticed someone here claiming 8+ hours battery on 13 inch so I decided to give it a shot.

I got a new 13 air with 1.86GHz/4GB/128GB yesterday and start to run on battery immediately. I was disappointed. The brightness was also set to 75% and I start to count the time from 25% while browsing MacRumors.com. And it only took 1h38m for battery descending from 25% to 0%. Again, pure web browsing and no heavy flash.

So here is my conclusion: On 75% brightness, 11 inch air's battery performs beyond advertised 5 hours and 13 inch's battery performs fair and normally should give you around 6h30m~7h.

Noise

I don't have equipments for measuring the noise, but while copying the same 10GB files from external drive to the machine, the fan noise from 13 inch is much louder than 11 inch.

Now I like my 11 inch more in general, although I really hate the 1366 x 768 screen. I don't know if I should sell the 13 inch or 11inch...



[edit]:
On my 11 inch air: battery capacity 4664
On my 13 inch air: battery capacity 6634

[edit2]:
I will do another test to see how long exactly my 13 inch can last after a full charge

 

[Scott6666]

Good info. Maybe check the 13" again after a few battery cycles because I understand it may take some time to "condition" the battery.

 

[citizenal]

I think my 13 inch ultimate runs great. I can watch a two hour movie, and then 5 to 6 episodes of my favorite show before the battery runs out. It really depends on if it's late at night and the brightness is turned down to 50% or if it's day and turned up to almost 70%. No experience on the 11 inch, though I hope to get one in the next couple of months and am really interested in other responses regarding battery life. sub.T

 

[miggitymac]

Your testing of the 13 may not have been entirely accurate...the part about using it on battery right out of the box...

You should try calibrating the battery and try again. Even though the battery may have been showing 25%, the actual charge may not have been 25%..know what I mean?

Maybe use the 11 and 13 inch side-by-side, both from full-charge after calibration, with the same apps running on the same brightness. Time the time it takes for each of their batteries to run out completely. That'd be more of a comparison.

 

[OSMac]

Love to hear your results after the 13/4 has had a full charge.

The main reason I'd go for a 13 is the claimed much longer battery life,
double according to Apple, and it being as silent as the 11.

If its battery is about the same as the 11 and its much louder, I'll just get a base 11....

 

[ReallyBigFeet]

I did several full rundown cycles on my 11" MBA over the past several days to condition it. Starting last night, I set them both up side by side, both starting at 100% and playing a non-HD series of MP4 video clips in a playlist (The Office Season 2 purchased from iTunes store), at 50% brightness on both units and volume at 30%, no other apps running:

11" 3h18m
13" 6h20m

I'm running the same test now to see if I get different results...will post again in a few more hours.

Both are the "ultimate" models, full config details in my sig below.

 

[OSMac]

Those numbers sound better, how did the fan noise compare?

 

[ReallyBigFeet]

While I was monitoring it, no fan noise from either device but if I put my ear right by the output vent I could tell they were both running softly.

Keep in mind these were SD resolution video clips running full screen. HD would be a different matter.

 

[hachre]

I easily get 8-9 hours on my 13" MBA, the battery shows 6832 mAh, and I usually have iTunes playing music, Safari or Chrome or both open with several tabs (plugins disabled, ClickToFlash etc), Mail running with an IMAP account and MobileMe, iCal running with MobileMe, Adium running connected to 5 networks, display at or slightly above 50%, no TimeMachine runs while on battery. I also occasionally start Preview or Quicktime Player, but only for rather short durations.

The power draw while idle (as described above, without me doing anything) is 600-800 mA.

I have compared these numbers to some of friends which have as much as 1000 mA MORE than what I have during idle. In that case you definitely have some software running in the background or some installed kext that heavily drains the battery. Those of my friends with idle drain numbers like that also only get around 5 hours usually.

 

[Star-fire]

I've been getting 5+ hours out of my 11" with brightness about 1/3 and browsing with wi-fi.

The machine is dead quiet, I never hear it.