Incredible Battery Life

I’ve publicly praised Apple for its honesty in reporting battery life over the past couple of years, and the iPhone 4 gives me no reason to stop.

The 4 has an integrated 5.25Whr battery. That’s around 95% of the battery capacity of the HTC EVO 4G, despite having much lower power frequirements. It’s also a 16% increase over the 4.51Whr battery that was in the iPhone 3GS. This means at bare minimum, assuming the iPhone 4 doesn’t draw any more power than the 3GS, we should get 16% more battery life.

In reality, we get much more.

When Apple introduced the iPhone 3G it dropped battery life to a level that we’d been stuck at ever since. The 3GS improved battery life a bit through better CPU power efficiency but you still didn’t have enough juice to get through a day without charging.

The iPhone 4 changes all of that. The combination of a larger battery and a more power efficient SoC results in an incredible amount of battery life.

Our first test is a basic web browsing benchmark. We've scripted almost two dozen webpages to load, pause for 20 seconds, then forward on to the next page. None of the pages use any Flash. This process repeats until the battery is dead. Screen brightness on the iPhones was set to 50% and the screens remained on the whole time.

Battery life improved nearly 38% with the iPhone 4. It's clear that while the A4 improved performance, the real improvement was in battery life. This test has enough idle time where good power management and low idle power can really impact the results. There's simply no other similar smartphone that can touch the 4's battery life.

We then repeated the same test over WiFi instead of 3G:

Apple claims the iPhone 4 will last for up to 10 hours over WiFi, we measured just under that at 9.96 hours. The improvement here is only 12.8%, which tells me that we're nearing the limit of how efficiently Apple can manage power in WiFi mode. There's a wall that we're quickly approaching with this current architecture.

To measure talk time we play MP3s on repeat into the mic of a phone and use it to call the phone being tested. The process continues until the test phone dies. In this case the screen is allowed to go to sleep, as it normally would be if you were talking on the phone:

Apple promised up to 7 hours of 3G talk time with the iPhone 4. We measured 7.47 hours. That's an increase of 54.9% over the iPhone 3GS. While in a phone call the majority of the A4 SoC is powered down, so the efficiency improvements here have to do with how much less power the A4 consumes while off and the new Skyworks 3G modem (the iPhone 3GS used an Infineon modem).

In our iOS 4 review we looked at the impact multitasking had on the iPhone 3GS' web browsing battery life. I ran our 3G web browsing test while playing music through Pandora in the background. I repeated the test with the iPhone 4 for today's article:

We actually see our largest battery life improvement in this test. With a 57.7% increase in battery life over the 3GS, the iPhone 4 is not only more efficient at idle workloads but also when the SoC is constantly busy. The A4 SoC is rumored to be built on a 45nm process compared to the 65nm SoC used in the 3GS. With a moderate increase in clock speed we should be seeing a lot of the power savings that a full node shrink brings to the table.

The battery life offered by the iPhone 4 is spectacular. My iPhone 3GS could hardly get through a full day of work while traveling, I'd always need to hunt for an outlet before heading into my dinner meeting. I'm about to take my first trip with the iPhone 4 but I get the feeling that I might finally be able to make it through dinner.

Early reports of 20 and 30 hours of battery life are simply exaggerated. They're only possible if you let the phone idle in your pocket for the majority of that time. In other words, if you don't use the phone it lasts for a long time. While that's a testament to the platform's incredible idle power, the real world usage is good enough to stand on its own. It's better than any iPhone or Android phone I've tested thus far.

Performance An iPhone with Bumpers
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  • Anand Lal Shimpi - Wednesday, June 30, 2010 - link

    It honestly is basic differences in UI design. Unified settings panels (iOS) vs. per-app options and global settings (Android), much more freedom to configure how you want things displayed/presented, extending all the way down to the keyboard (Android) vs. a single Apple dictated way. These are the types of things that make the iPhone more of an appliance, basically if you like Apple's approach then there's no better device for you. A *lot* of users don't, and that's where Android comes in to play. I don't believe the power and flexibility of a PC-like device is a bad thing, but not everyone feels the same way. Take a die hard iPhone user and give them your Droid, you'll probably get the same response I did when I let some of those folks use the Nexus One or EVO 4G. It's really a preference thing, it reminds me a lot of the Mac vs. PC debates.

    And while i haven't played with the Droid, the scrolling issue is present on the Nexus One with live wallpapers disabled as well as enabled. Although enabling them makes it worse. The HTC Incredible is the first Android phone I've used that actually improved it, although didn't solve it completely.

    I expect that in the next major Android update Google will fix it once and for all. I hope.

    Take care,
    Anand
  • JAS - Wednesday, June 30, 2010 - link

    Yes, "more open, more configurable" is a double-edged sword. A comparison of Microsoft Windows and Macintosh OS X is apt in this regard.

    P.S. -- Can we advance beyond the juvenile label of "fanboy" when criticizing a person's like for a product?
  • bplewis24 - Wednesday, June 30, 2010 - link

    Juvenile comes with the intent. I have the utmost respect for Anand and his opinion/reviews. If you take "fanboy" as a disparaging remark, fine, but it essentially means you have a bias or preference that obscures some of your objectivity.

    Brandon
  • The0ne - Wednesday, June 30, 2010 - link

    As I've often expressed here, I like the reviews to not have any 1st person views. I don't care if one waited for 6hours for a phone. I don't want to hear any "this phone is the all to be". I just want a detail review of the phone and it's features. If one can qualify and/or quantify the differences with other products great. If you can't then don't, rather then having the innate urge to add your own opinions.

    Yes, the apple UI is more smooth, the experience is more enjoyable. The druid UI is a tad slower but by no means going to destroy or ruin anyone's experience. If you can't justify it, don't!

    Lastly, the problem with 1st person perspectives being included in reviews and especially technical reports is that the reader will see it as favoritism. This is why absolutely NO credible technical and scientific review/report is written this way. I don't write my engineering tests and reports in 1st person. Just stick to the material and leave opinions out of it. This type of review ONLY happens online and sadly it's affecting technical and scientific materials as well.

    Do the job, state the facts and tests and let the reader decide how to deal with it. Don't offer the reader any types of suggestion or persuasive comments. If you do include it, like other websites, in the editorial section or something similar.
  • kmmatney - Wednesday, June 30, 2010 - link

    I wouldn't want to read reviews that just state facts. I'm an engineer/scientist and have written many peer-reviewed scientific papers. For tech reviews, though, I really appreciate user experience. There are just too many intangibles that can't be expressed by facts and tests. That's why I have been reading Anadtech for over 11 years - I appreciate the blend of techiness and user experience.
  • totenkopf - Wednesday, June 30, 2010 - link

    I have to agree with TheOne on this. Also, you can express "intangibles" without using the first person... If the iPhone's UI feels smoother than another phone then just say that and leave off the "I feel" bit.

    Remember that any statement comparing the iPhone to "Android" will have its flaws. You can only compare the iPhone 4 to other phones, not android. Any such statement will inherently be some form of generalization. Besides, Comparisons made with particular Android phones will be far more helpful as many android phones offer an experience distinct form any other Android phone.

    It's really not that uncommon for iPhone users to play with an Android phone and really like it. Many of them actually seem quite surprised that they actually like it; some merely think that iOS is the only show in town as it has been the best for a long time. Widgets, in particular, offer a lot of customization and, perhaps just as importantly, personalization, that many iPhone users seem to appreciate. If used correctly, widgets can multiply the functionality of your phone many times over, and in some cases preclude running many apps at all. That said, setting up an android with just the way you like it and hunting down the newest and best apps and widgets can be an ongoing struggle. However, many people will enjoy it immensely if for no other reason than to make their phone that much better in their own eyes.

    There! My experience with android without sounding too biased... I think ;) It certainly sounds better than "Android rulz 'cus widgets are soo good and apple doesn't even have them because apple is fail!"
  • John Sawyer - Thursday, July 1, 2010 - link

    As an iPhone user for the past year, I can concur with your observation that many iPhone users would be impressed with the latest Android phones. I've tried the Evo for about ten minutes, and during that time, I did some web browsing, ran some apps, etc., and it was fast (even with a 3G connection), seemed polished, and I wouldn't complain too much if it was the only phone I had to use. If I had the chance to use it longer, I might start seeing its deficiencies, but a quick look, looked good.

    Though a week later, the iPhone 4 was released, and I was blown away by its display, which no other phone matches yet, though I'm somewhat biased about that since I like to be able to read tiny text.
  • The0ne - Thursday, July 1, 2010 - link

    The problem with user experience is that it's just that and it affects how readers perceive the product. I don't mind really that reviews are done this way, but many are done extremely bad. Here are a few examples of comments people include in their reviews...

    "I let me wife play with it for a day or so and she loves it!" This is quite common for PMP player reviews.

    "This is the best thing ever to come out on a phone..." Best thing is more or less an exaggeration. Way too many improper adjectives are used in reviews. Anandtech is no exception to this.

    "I like it..." Okay, that means what, I should too?
  • strikeback03 - Thursday, July 1, 2010 - link

    I disagree, in that I think the subjective "feel" of one phone (and OS) relative to another is largely subjective and can't be quantified in just plain numbers. Would you really feel better if he stated that "after observation with a high speed camera phone X illustrates a scroll with 5 frames and phone Y does so with 20" as opposed to "phone X is noticeably choppier"? Or say for example Sprint shipped a special edition EVO with 768MB RAM, we know that is 50% more, but would it actually make a difference in your interaction with the phone if you had less than 20 apps open?

    I have an HTC Touch Diamond, a WM 6.1 phone with TouchFlo 3d. None of the reviews I read before purchase adequately described how clunky the interaction between the TouchFlo plugin and the background OS is, or how poorly optimized WM6.1 is for a touchscreen, and certainly not how the speed of the device goes from marginal when new to completely unacceptable after a few months and requires a hard reset to restore.
  • ipredroid - Saturday, July 3, 2010 - link

    What many fail to realize is with out opinion there would only be numbers and no reason to have site with user friendly technical data (a site like this). Everyone's opinion is biased or influenced by something, simply sticky by facts and zero emotion devoted towards every product is impossible. Many opinions itself is laced in bias preference for facts.

    I for one want as much information as possible not half the information.

    Facts and opinions have and always will be better than just one of them. Would you rather have technical data about someones trip to Mt. Everest or an opinion. I would want both, so would everyone else or else you are missing facts.

    Science and opinion go hand in hand. Cause and effect.

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