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applewins
Jul 21, 2011, 12:05 PM
Hi
I have some questions about the battery life in the new MBA's.

1.) Does the backlit keyboard affects the battery life at all? When yes, I guess it's a matter of minutes not like an hour?

2.) Do you really get the 5h /7h battery on the 11'' and 13'' ? May it change a lot if you do heavy work like photoshop or movie rendering or very easy stuff like using pages? So would it be possible to get remarkable more than 5h/7h or less?

3.) I've heard that the i7 processors turbo-boost affects the battery life too? In this case we get more processing power and we lose battery life, may anybody tell us more about that? With the i5 processor this problem doesn't exist because the lack of turbo-boost, right?



Since the 11'' and 13'' have the same processors, graphics and RAM available, the only difference (except size and weight) is the SSD storage and the battery life. So it seems to many of us very important, that we really get these 5h of battery on the 11'' even with an i7 processor and heavy processing tasks.

Thanks for your answers :)



MacRumorUser
Jul 21, 2011, 12:17 PM
1) yes it will reduce battery life. If I was at full brightness I imagine it would knock 45mins - 1hr off battery life based.

2) on full load - both the i5 & i7 processors will not keep your machine running for 5 hours - it would be more like 2-2.5 hours.

3) whilst the i7 on full turbo prob does take more battery power, the reality is for that 20 minutes you lose in battery - you gain 600mhz extra processing power on the 11" model anyway. That performance gain whilst working under full load is more of a benefit than the battery defecit.




So if you get the 11" and are working under full load on the i5 the chances are you will get 2.5 hours. On the i7 it will likely be just over 2 hours. You will not get anything like 5 hours on either machine when pushing it.

5 hours is based on screen brightness at around 50% with light web browsing. In which case even with an i7 running such light tasks it probably will last just as long as the i5 as neither are being stressed.

applewins
Jul 21, 2011, 12:33 PM
Thanks for your answer, I didn't expect such a huge affect on battery life :(

sweatygorilla
Jul 21, 2011, 01:00 PM
5 hours is based on screen brightness at around 50% with light web browsing. In which case even with an i7 running such light tasks it probably will last just as long as the i5 as neither are being stressed.

Hmm... but anandtech tests show that at 50% brightness, with itunes runing and light webbrowsing, you are able to get almost 7 hours (420min). I am assuming that while the new 11" battery life is slightly worse, it can't possibly be 2 hours worse?

Also, I was wondering how much batterylife one could get if they had the brightness down all the way to 20-30%, while doing mostly word processing and maybe some web browsing. Think the 11" could reach 8 hours?

MacRumorUser
Jul 21, 2011, 01:40 PM
Hmm... but anandtech tests show that at 50% brightness, with itunes runing and light webbrowsing, you are able to get almost 7 hours (420min). I am assuming that while the new 11" battery life is slightly worse, it can't possibly be 2 hours worse?

Also, I was wondering how much batterylife one could get if they had the brightness down all the way to 20-30%, while doing mostly word processing and maybe some web browsing. Think the 11" could reach 8 hours?

I assume that was with the last revision?

Never was I able to get that out of my MacBook air 11. Most I got was 5hr30 using coolbook to undervolt and brightness around 40% with light work. (web without flash or HTML 5 video, email, office 2011). Any less work and I wouldn't have been using it ;)

Soon as you start using the computer with programes like photoshop or aperture battery life depleted hugely to as I say 2.5-3hrs tops.

sweatygorilla
Jul 21, 2011, 02:33 PM
I assume that was with the last revision?

Never was I able to get that out of my MacBook air 11. Most I got was 5hr30 using coolbook to undervolt and brightness around 40% with light work. (web without flash or HTML 5 video, email, office 2011). Any less work and I wouldn't have been using it ;)

Soon as you start using the computer with programes like photoshop or aperture battery life depleted hugely to as I say 2.5-3hrs tops.


Yep, that was with the last revision. The 11" got 7 hours, while the 13" got 11 hours!

It's a real shame to hear that you could only get 5hr30 max.. I might be leaning more towards the 13" than, since I was hoping for a laptop that could last at least 6 hours (preferably 7 or 8) with brightness set as really low and mainly word proccess/looking through academic journals. It's really too bad since I really like the 11" form factor and the performance is at this point pretty simialr for the two machines.