Battery Life

I published some initial results about the iPhone 3G’s battery life here, but now it’s time for a full analysis of what the phone can do.

Initial tear-down reports show that Apple switched to a removable battery with the iPhone 3G, removable in the sense that it isn’t soldered to anything inside the case, but still requires that you take apart your iPhone to get to it. Not having a removable battery wasn’t really an issue for me with the first iPhone since I tend to go through phones quicker than their batteries stop holding a charge. Granted even if you don’t keep your phones for that long, it would be nice to be able to swap in a new battery if you’re running low - especially with how much power the 3G modem gobbles up.

The first question about the iPhone 3G is its talk time when 3G is enabled. Most users won’t want to keep switching 3G on and off and I suspect that many will just leave it enabled, so what will that do to talk time? To test this I played music back on a notebook through some headphones placed right at the mic on the iPhone 3G. The phone was flipped over on a table to trigger its sensor and shut off the display, thus simulating a real call. I called my Vonage deskline from the iPhone and got to listen to 50 Cent play over and over again for hours, a homage to what I did last year with the first iPhone.

Battery Life Test - Talk Time

Battery life with 3G enabled was 4 hours and 44 minutes, down from nearly 6 hours when I tested the original iPhone. Turning off the 3G modem and switching to Edge, my call time went up to 6 hours and 4 minutes, about where it should be based on my original iPhone test results. With less than 5 hours of talk time, if you plan on doing a lot of talking you had better shut off 3G mode on the iPhone.

Unfortunately Apple doesn’t make turning 3G on/off as easy as silencing your phone. It takes three taps to get to the menu where you can enable/disable 3G from the home screen, another tap to change the setting and one more tap to get back home. It’s not terrible, but it’s definitely not the most easily accessible thing in the world.

Note that this is far less than the 10 hours of talk time that Apple claims on the iPhone 3G’s spec sheet, and also keep in mind that this is the best case scenario. My voice test just involves the phone sitting in one location with music playing through the mic. Battery life could go down significantly if you were using the phone in an area with lower signal strength or if you were constantly hopping between cell towers.

To test web browsing I ran the same script I did for the iPhone follow-up article I wrote last year: (note that you shouldn't compare results between the original iPhone review and today's, it looks like changes AT&T has made in my area have changed signal strength considerably).

Our web browsing test is slightly different from what we ran in the iPhone review. We used a total of 7 web pages, but of much larger sizes than our first test. The first page was simply a counter page, the second was our review of the Core 2 Duo E6750, followed by our article on AMD's Phenom introduction, an excerpt from our Quad FX article, our entire iPhone review, an article on Intel's Turbo Memory and our entire AMD Radeon 2900 XT review.

Each page was loaded by the browser and was set to forward to the next page (in the above order) after 10 seconds; the iPhone’s brightness was set to approximately 50%. All backlight timers were disabled. Bluetooth was enabled but not paired to any devices.

Battery Life Test - Web Browsing

WiFi continues to take the cake at 6 hours and 40 minutes of total usage, which as we found out last year is what we should expect. Next up is performance on Edge, with the new iPhone lasting just over 4 hours. And finally we have 3G browsing performance: our battery was dead in 3 hours and 17 minutes.

Combine web browsing, email and voice and you’ll find that the iPhone 3G, in 3G mode, will burn through your battery in a matter of a few hours. The speed of 3G is nice, but the battery life suffers tremendously - pack an extra charger.

3G Performance GPS.........kinda
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  • buckdutter - Friday, August 22, 2008 - link

    AT&T's coverage could indeed be better, but then again they are still rebuilding from when they decided to switch from TDMA to GSM, instead of following the natural path to CDMA, which Verizon, Sprint, and Alltel (soon to be Verizon) use, as well as many more localized carriers. The problem with CDMA is that it is going nowhere. The majority of the world is GSM, and CDMA is becoming more and more marginalized, in fact in the next 4 or 5 years CDMA will be practically phased out in the US. Verizon (and Alltel) will be switching to LTE, a GSM based technology which will be a rough transition - either resulting in sacrificed coverage, or more expensive devices (like Verizons expensive "world edition phones") that will run on both their networks. Either way, they will be doing what AT&T (Cingular, whatever) did 4 or 5 years ago, and much later in the game.

    Meanwhile AT&T will make a natural transition from their 3G, which is in all fairness not nearly as widespread as EVDO at the moment, to LTE. Sprint will be going WiMax. Not one major carrier in the US or abroad has made a commitment to the future of CDMA. Verizon has held on to EVDO as long as it could, and has prolonged having to switch, but they are beginning to hit the limitations of EVDO, meanwhile 3G is just getting started, with AT&T planning to follow suit of carriers abroad and boost the speeds to around 20mbps in mid-2009. EVDO will be topping out around 3.2 at most, if even that.

    While having used all the services I strongly disagree with saying that Sprint or T-Mobile even come close to AT&T for coverage, it is largely regional subjective, and is really not fair to work in experiences in one localized area into the review for the phone. Like them or hate them, AT&T recognized early that GSM was the roadmap to go. Like it or hate it, blame Verizon for delaying the inevitable for so long...it makes no sense for Apple to make a CDMA phone when it is so limited in implementation globally. Because of that decision they are the most widespread GSM provider in the US (the US was a little late in getting into the GSM game).

    In the end, AT&T may have a lot of ground to cover, but we should be excited what at least one U.S. carrier took the leap and is building out a GSM network in the states, even though it meant making the sacrifice of less coverage in rural areas as they build the new network out. It will be interesting to see how Verizon copes with having to change over.
    Reply
  • Hrel - Tuesday, August 12, 2008 - link

    Over 2 years the new iphone plane costs an extra 60 bucks, but the upfront cost is 300 dollars less. The iphone 3G is less expensive in every way; even with the incremental increase in contract cost. I'm confused that I need to point this out considering you say it in your article then contradict yourself by saying the old plan and phone was less expensive. Total cost over two years the new one is 240 dollars less. Reply
  • maxnix - Thursday, July 31, 2008 - link

    With no user replaceable battery, it is a toy, not a reliable business device.

    It seems to me that 90% of the users I see are fiddling about on it with their fingers and not even 10% use Bluetooth. Are there still no voice driven commands? That's how I use my phone.

    Seems like a great device for someone who wants to make calls on their iPod when they are not listening to a lossy audio source.

    Jobs is the new PT Barnum in that he fully exploits the "A sucker's born every minute..." credo. The world is full of lemmings.
    Reply
  • maxnix - Thursday, July 31, 2008 - link

    Welcome fanboys to AT&T's limited 3G. The rest of the world has been there for 5 years. Reply
  • steveyballmer - Wednesday, July 23, 2008 - link

    Sprint or whoever has released the perfect smart phone! It's based on Windows Mobile and is beautiful to behold!
    There is nothing else anything like it! The Instinct!

    The ZunePhone has suffered a few setbacks so this will have to do until we work out the bugs. Buy it! Don't be decieved by that imitation iPhumb.

    http://fakesteveballmer.blogspot.com">http://fakesteveballmer.blogspot.com
    Reply
  • Lezmaka - Monday, July 21, 2008 - link

    I think there's a fairly obvious (to me anyway) reason why the talk time measured is almost half the time the specs state, beyond the best case scenario stuff.

    In most conversations, there's a significant amount of dead air. Even if it's only 1/10 - 1/4 of a second at a time, over the course of several hours, that will add up. But with most music, there's almost no dead air. Even when the person isn't saying something, there's at least some sound being generated. Detecting that dead air and not transmitting would probably be the best for battery life, but even if it continually transmits, the compression would reduce the amount of data transmitted to almost nothing.

    I would guess that choosing an audio source that more closely matches an actual conversation would provide a somewhat more accurate test result. But I'm not expert, so what the hell do I know?
    Reply
  • Giacomo - Monday, July 21, 2008 - link

    Ehm... No man, there's no way this could influence battery life. No matter how intense is the information in the call, most of the energy drain is due to the "line" itself... Keeping the full-duplex conversation online.

    Everything else left to the battery is the loudspkeaker consumption... But it's a ridicolous amount, you won't be able to measure its impact.

    Giacomo
    Reply
  • donhoffman - Tuesday, July 29, 2008 - link

    Actually the original commenter on this was correct. This is a time-honored technique for getting more battery life out of cell phones. Channel allocation for voice calls is done at call setup. A continuous data stream is not needed to keep up the "line". If either end of the call has nothing to send, it does not need to transmit, saving significant power. The technique used in this article probably does underestimate the battery life. Not by 100%, but maybe 20-30%. Transmit power is much larger than audio power. That is why you get 24 hours listening to music on the iPod side, but only 5 or so hours doing cellular phone calls.




    Reply
  • nichomach - Sunday, July 20, 2008 - link

    Not wishing to get into whether the new iPhone is all that, I'd note that the enforced PIN code when using Exchange is usually a policy setting defined in Exchange, and there's a choice about enabling it. That choice'll be made by your Exchange admin(s). If they enable it - personally, I do - then I'd expect it to be enforced on any device that claims to support Activesync. One of my arguments with Nokia's Mail for Exchange client, for instance, is that it doesn't (or didn't) properly support policies like that; that the iPhone does makes it a viable choice if I end up with a director demanding one. If you're using your phone in a corporate environment, then you may be sending and receiving confidential stuff. Enforcing a PIN and supporting remote wipe properly is the sine qua non as far as I'm concerned. Reply
  • Schugy - Sunday, July 20, 2008 - link

    Openmoko will have the best 3rd party support while Nokia and Google (Maemo / Android) have their own ressources. But regarding their openness they are evil. The FIC Freerunner is a nice phone but the Openmoko project still has to develop a lot.
    On the other hand I think that a Open Pandora handheld with a USB HSDPA modem (maybe builtin in future revisions) is a lot more usable and even has game controls. Telephony and navigation could be done via a bt headset+voip and gps receiver.

    All the platforms will feature ports of killer apps like pidgin IM, scummvm, evolution e-mail and lots more. Ports of gnash, the GNU flash player, are possible too but I would suggest to get rid of these stupid and annoying banner ad players. A nice stream or download link for mp4-files will make your full featured (fullscreen / post processing filters) mplayer happy.
    Reply

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