By Prince McLean

Published: 08:25 AM EST (05:25 AM PST)

Internal new hardware feature drawbacks: battery life.

Both 3G mobile networking and GPS tracking place major new demands on the battery. However, the iPhone 3G employs a number of power efficiency tricks intended to help the new phone last nearly as long on a charge as the previous model. Apple has also imposed a number of limiting guidelines upon iPhone app developers to keep battery consumption low. For example, programmers are advised to avoid constant polling of data networks or excessively frequent location lookups. 

All together, the new model delivers the same performance in playing back music or video (24 hours of audio or 7 hours of video, even despite the speaker improvements and louder volume), about the same in browsing the web (6 hours over WiFi, 5 hours using 3G mobile service; the original iPhone wasn't rated any better using EDGE, but independent tests indicate the original iPhone could browse twice as long on the same charge, of course that's also downloading less than half as much content!), but significantly less talk time when using 3G networks (due to the advanced signal processing required by UMTS; it's rated for 10 hours of talk time on GSM versus 5 hours of talk using 3G). The power consuming 3G service can be turned off to maximize talk time if you're in a location where you know you're not needing it, but it doesn't automatically downgrade for you when it thinks you can do without it.

A variety of independent reviewers found Apple's claim of five hours of 3G talk time to be fairly reasonable, with half reporting closer to six hours of 3G talk time. When mixing in 3G web browsing and other data access, the same five hour claim was more widely disputed, with several reviewers claiming they could use 3G data for only about 3.5 hours. The exact mix of tasks performed has a lot to do with how fast the battery runs down.



And of course, 3G browsing and GPS accuracy make using the iPhone's existing features far more attractive, so typical users will likely find themselves operating their phones longer and more frequently, resulting in a shorter battery life than they might have seen when limited by the slower EDGE network and the less accurate location positioning of the original model. The number one complaint echoed by upgrading iPhone users is that they are seeing less battery life. Upcoming software updates might help a bit, but being ready with an add on battery pack (either using an iPod dock connector or generic packs that supply power over USB) makes a lot of sense. Apple also offers some suggestions on how to maximize battery life on the iPhone.

When push comes to shove

There's other factors that also make a significant drag upon the iPhone 3G's battery life. One is the new push messaging features enabled by the iPhone 2.0 software update (which will be detailed in a followup segment). Push messaging is intended to save mobile battery power, as it spares devices from needing to regularly connect to an email server to ask for new messages. Instead, the server pushes new email and other events as needed, so the mobile device only transmits when prompted by the server, similar to receiving an SMS text message.

However, because the iPhone 2.0 software adds contacts, calendar, and bookmark syncing as part of its push services, the end result is that the typical iPhone likely now has more to do; rather than just checking email on a regular basis, it's receiving updates from a variety of message types, with a frequency related to how often the user's mailbox, contacts, calendar items, and web bookmarks change. 

That means iPhone 2.0's push services, whether delivered from a company's Microsoft Exchange Server or from Apple's own MobileMe service, represent a significant new drain on battery life. This will be particularly noticeable for users who were only checking for new email manually or on a schedule of every half hour or less. 

Unlimited apps

In addition to push messaging, another potential battery consuming feature in the iPhone 2.0 software are its new third party applications. Just like push services, 3G, and GPS, the added benefits of the new selection of apps from iTunes (also downloadable directly from the iPhone's new Apps Store icon if you really want to tax your battery) come at a cost. 

The more you use the iPhone, the less battery life you can expect. Graphically intensive games and apps that rely upon network connectivity both represent a significant new impact on battery life.

A followup segment will take a closer look at how the iPhone 2.0 software and the new third party applications, as well as Apple's own included apps, offer a variety of strong new advantages while demanding more from the battery. This impacts both the new iPhone 3G and existing iPhones upgraded to the iPhone 2.0 software. But first, we'll present a look at how the iPhone 3G's hardware stacks up with other smartphones on the market, along with a comparison of how it compares to the existing iPhone, and whether it's worth it to upgrade.

Submit your own observations and bug reports related to the iPhone 3G hardware and iPhone 2.0 software in comments or emailing us directly.