The Best Battery Life I’ve Ever Seen

To find out how well the new lithium polymer battery does I ran my usual suite of Mac battery life tests. First up was my wireless web browsing test:

The wireless web browsing test uses the 802.11n connection to browse a series of 20 web pages varying in size, spending 20 seconds on each page (I timed how long it takes me to read a page on Digg and came up with 36 seconds; I standardized on 20 seconds for the test to make things a little more stressful). The test continues to loop all while playing MP3s in iTunes.

This is an extremely light test as none of the web pages have any flash ads, but it’s a valid test of very light wireless usage.

Eight, freakin, hours. I couldn't believe it. In my lightest test, the new 15-inch MacBook Pro lasted eight hours and eight minutes. That's with the screen at half brightness (completely usable) and no funny optimizations. The notebook is just playing music and surfing through a lot of my old reviews. There's no way this could be right. Maybe my test was too light?

I threw together another test just to make sure. The key flaw in my initial wireless web browsing test is that it none of web pages have any Flash on them. While constantly loading web pages will ensure the CPU can't go into deep sleep, Flash on the pages would make sure that the CPU utilization remains higher at all times. The next test I put together was this:

I strung together 8 reviews on AnandTech and put them each on a single page, images and all. I then scoured the web for big, animated Flash ads and added anywhere from 1 - 4 ads per page; all Flash. Each page is designed to forward to the next after 10 seconds and the loop continues indefinitely. On each machine I opened three Safari windows and pointed them at the first page in the sequence. In the background, once more, I had iTunes playing MP3s.

I found that CPU utilization varied from 5 - 35% during this test, which is about what I saw when I was actually surfing the web myself. The addition of Flash should make it more stressful, but it's still a fairly light usage test. My original web browsing test got us 8 hours, so what about this new one?

  MacBook Pro 2009 MacBook Pro Late 2008
Wireless Web Browsing w/ Flash 6.48 hours 3.28 hours


Six and a half hours, out of a 5.5 lbs notebook. For comparison, the older MacBook Pro could only manage 3 hours and 17 minutes in the same test. The new notebook lasted almost twice as long. Mathematically, this doesn't make sense. There's only a 46% increase in battery capacity, there shouldn’t be a ~100% increase in battery life...ever.

While the original web browsing test was using data from my original unibody MacBook Pro review, this second web test used a brand new MacBook Pro (purchased just weeks before this week's MacBook Pro announcement). The two notebooks had the same amount of memory (4GB), the older MacBook Pro had a slower CPU (2.4GHz vs. 2.53GHz) and a 7200RPM hard drive but the differences shouldn’t account for an extra 54% increase in battery life.

Apple must have done more than just increase battery capacity in the new MacBook Pro. My third test continues to support my findings. This is my heavy workload benchmark.

For this benchmark I'm downloading 10GB worth of files from the net (constant writes to the drive), browsing the web (same test as the first one) and watching the first two episodes of Firefly encoded in a 480p XviD format (Quicktime is set to loop the content until the system dies).

The older MacBook Pro managed 3.25 hours in this test. The new one? Just under 5:

That's a 51% improvement in battery life. It's close enough to the max theoretical 46% improvement for me to think that the significant gains in wireless web browsing are due to improvements in idle power optimizations. It's possible that all of the components in the new MacBook Pro have been optimized for lower voltages at idle.

The battery tests are repeatable however. I saw anywhere from a 50 - 100% improvement in battery life over the old MacBook Pro. Given the increase in battery capacity alone, you should see no less than a 46% increase in battery life. Exactly what is accounting for the expanded life above and beyond that, I'm not sure.

Either way, Apple's 7 hour claim is well within reason. For light workloads, even on WiFi, you can easily expect 6.5 - 8 hours out of the new 15-inch MBP. As I write this article on that very system I'm told that I have nearly 8.5 hours left on my charge. If you do a lot of writing on your notebook, the new MBP is exactly what you'll want; it will easily last you on a cross-country flight if you need to get work done.

I think I've just found my new writer's companion

My heaviest workload delivered just under 5 hours of battery life, a figure that the old MBP could only attain while running my lightest workload. This thing rocks.

I also have to commend Apple for delivering realistic battery life specs on its laptop. While 7 hours definitely involves a light workload, it is more than attainable as I've shown in the tests above.

A quick search shows that even Dell's Studio 15 only offers a battery rating of up to 5.5 hours. It looks like, once again, other notebook makers will have to play catch up to Apple in this department.

Other Hardware Changes Lower Power Consumption = Smaller Power Bricks


View All Comments

  • Pirks - Saturday, June 13, 2009 - link

    C'mon man, how else winzealots could defend themselves against such a thorough and lubeless pwning by that famous fruity company? They know they lost it in a fair comparison so they try to squeeze in any old and slow Pentium era junk they can found, just to pretend to not losing a face. Hilarious! You guys keep posting here, keep the show running, gimme some atom or another shittyslow Wintel laptop, I love your lame excuses! :))) So much fun today... ahhhh... Reply
  • BushLin - Tuesday, June 16, 2009 - link

    I have no loving affinity to any company... I like to buy good value, high performance parts, hence why I normally overlook Apple.
    If these rather expensive and well marketed machines could get even close to that kind of battery life under Windows I'd be impressed. Right now I just see some tests under a proprietary OS, a bunch of Fanboys with too much time on their hands who should be where they belong, in Starbucks, posing, rather than on a serious tech site.
  • Hacp - Saturday, June 13, 2009 - link

    Samsung's new drives with the new controlelsr, the same ones that are in the ocz summit and corsair p256 have a built in cleaning function when the drives are in an idle state. This makes worst case scenario performance a non factor in these drives. Reply
  • iwodo - Sunday, June 14, 2009 - link

    If that is true even for the 128Gb SSD that apple offer then it would be a good deal from Apple. Reply
  • misium - Saturday, June 13, 2009 - link

    Each time a Li-ion or polymer battery is charged its capacity decreases. Li-polymer batteries deteriorate even when they are not used - just by lying on the shelf.
    This explains why older laptops have lower battery time - their batteries are older.
    You should test the new laptop in a year or two to make a fair comparison.
    Also you could just put fresh batteries into the old laptops.
  • Anand Lal Shimpi - Sunday, June 14, 2009 - link

    All of the laptops here used brand new batteries, with the exception of the 2006 Core Duo based MacBook Pro. I did test the 2006 notebook with a new battery and found an extra ~25 minutes of battery life I believe.

    Take care,
  • peroni - Saturday, June 13, 2009 - link

    The new Acer timeline laptops based on Intel CULV processors claim a battery life of 8 hours, and that's when running vista!
    I bet with Win7 they could squeeze an extra hour out of it.
    The processor is only running at 1.4GHz but on the other hand they're very light (for the screen size)
    I'd love to see an Anandtech test on them.
  • JarredWalton - Monday, June 15, 2009 - link

    Already requested. Can't wait to see how it fares in our tests.... Reply
  • Johnmcl7 - Saturday, June 13, 2009 - link

    but then again why let niggling little things such as facts get in the way of a nice and tidy Apple marketting piece. What a load of nonsense this is from a supposedly reputable tech site right from the start:

    "Apple did some clever work on its own here."

    Total and utter nonsense, Apple have done no such clever work at all as it's all been done already. Many years ago Ericsson showed how polymer batteries could be used to reduce size in their super slim T28 and Apple are far from the first to do so for laptops. I expect the every day person on the street to get taken in by Apple's marketting but not a site like Anandtech, I'm also surprised that the battery no longer being removeable isn't really criticised as I think that's a really bad loss. Aside from not being able to use a second battery which is very handy for those who want good batterylife and there are single batteries out there that easily exceed these Macbooks but also if you have a failure you can easily swap it out for another.

    "There’s no other way to say this. If you care about battery life and portability at all, buy the new MacBook Pro. Go to the Apple store and buy one. While I only tested the 15” model, I’m guessing the 13” model should leave a similar lasting impression."

    Well I had to laugh at this point although I guess it's expecting too much by now to expect AT to have any clue about other laptops on the market. I'm currently typing this on a Sony laptop I bought back in 2005 which can last around eight hours on its normal battery and on its extended battery which is currently fitted it's around 12-13 hours putting these Macbooks to shame. As the battery is also removeable both together means the machine can last a long, long time away from the mains. Why someone would want a 15.4 inch Macbook (or even 13.3in) for batterylife and portability when there's other machines that are smaller, lighter and better batterylife I've no idea - the article reads as an advert for Apple and reading the conclusion you'd think AT were on a commission from them. It must be annoying for the likes of Sony though and others who bring genuine innovation to the market, get ignored then when Apple release the same technology a few years down the line they then get all the praise for it.
  • djuero - Saturday, July 04, 2009 - link

    Sure you're able to post links to comparable machines to prove that? Reply

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