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

  • BushLin - Tuesday, June 16, 2009 - link

    Right now, you may not care that your battery isn't removable. After 13 months, when it's failed and Apple want to charge you the price of a netbook to take it in and replace it, you may do. Reply
  • Johnmcl7 - Sunday, June 14, 2009 - link

    It's been done already long before Apple (as with most of their innovations) plenty of companies have produced laptops with extremely long batterylife but without fixing the battery.

    Apple's solution is nothing clever as all they've done is sacrifice the removeable battery, I just really hope other companies don't do this as well as has been happening in the mp3 player market particularly with Sandisk.
  • iwodo - Saturday, June 13, 2009 - link

    From an environmental standpoint, having battery built in means you will have to bring the Notebook back to Apple to buy a new battery. This would means your old battery is properly deposited.

    I am surely there will be third party, or possibly even apple would make an External battery for all Macbook that plugs into the power plug.
  • djuero - Saturday, July 04, 2009 - link

    Those products (external batteries) are available from different companies already... Reply
  • sendai - Sunday, June 14, 2009 - link

    Yup, they've been around for ages, though I'd say Apple have energised the market for them:">">">
  • iwodo - Sunday, June 14, 2009 - link

    Now it has been proven that there are massive amount of external power out there. I wonder why the need for a removable 2nd battery?
    With Internal battery, you get more space, longer battery, and more environmental friendly. Why would you need a 2nd battery when you can do the same with external power?
  • PlasmaBomb - Saturday, June 13, 2009 - link

    That is an interesting thought. Wonder how feasible it is... Reply
  • Pandamonium - Saturday, June 13, 2009 - link

    I'm looking at the specs and can't help but think Apple moved the 13" unibody MB into their MBP line and added a price cut to boot. My wife just got a "free" 13" unibody. (Her MB was a legit lemon, and after 5 or 6 Applecare repairs, the store just gave her a replacement) Anyway, the specs of her replacement are in line with what I see here for the MBP version. We don't have the machine with us to compare removable batteries, but we'll definitely do that after our honeymoon. Reply
  • gcor - Saturday, June 13, 2009 - link

    For a truly portable machine for getting stuff done, wouldn't an 11" netbook be a better option than a MacBook?

    Right now I don't think any of the MacBooks stack up as well as machines like the Acer Aspire 11.6".

    11-12 inch netbooks seems to; tick all my must haves (see below), have excellent weight, and great form factor. While I would prefer an OS-X machine, MacBooks that meet my must haves are twice the weight and 4 times the price of a comparable netbook.

    For my needs at university. I've settled on the following requirements:

    Absolute must haves are:

    - Display sufficient to view and skim read multi-column research papers:
    >= 1200x800
    >= 11"
    - Suffient performance to:
    - quickly flick thourgh PDFs and powerpoints
    - create and edit files using MS Office
    - surf the web
    - >= 8 hours battery for the functions above
    - fullsize laptop keyboard
    - OS-X or Windows (no Linux due to MS Office:-( )
    - WiFi, tackpad, >=20Gb free disk, USB, speakers.

    In addition, my nice to haves are:
    - OS-X over Windows
    - Light
    - Thin
    - Low price
  • iwodo - Saturday, June 13, 2009 - link

    Snow Leopard were suppose to speed things up, May be it will bring some even greater battery life. May be a retest once SL is out?

    I can imagine future Macbook Pro having 12 hours battery life if it has an SSD and OLED display.

    Apple could surely make an interesting Netbook or Cheaper Macbook Air with Dual Core Atom with these Battery inside.

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