What is the battery life of the original iPhone? Can you replace the battery?

Please note that this Q&A refers to the original iPhone. The original iPhone was replaced by the iPhone 3G on June 9, 2008. For details regarding the battery used in the iPhone 3G, please refer to "How does the battery life of the iPhone 3G compare to the original iPhone in real-world tests? Can you replace the battery in the iPhone 3G?"

Upon its unveiling on January 9, 2007, Apple reported that the iPhone was to provide "up to" 16 hours of audio playback and "up to" 5 hours of "talk, video, and browsing". On June 18, 2007, Apple boosted these numbers to "up to" 8 hours of talk time, 24 hours of audio playback, 7 hours of video playback, and 6 hours of web browsing. Apple also revealed that the iPhone provides "up to" 250 hours of standby time.

In real-world tests, the always excellent MacInTouch reported that:

We ran the battery down to 10% with just shy of nine hours of usage. (iPhone tracks "usage", which is all the time it spends not in standby since its last complete charge.) A majority of that time was spent using Internet via WiFi, with some EDGE, occasional photo taking, and about an hour and a half of phone calls.

Apple claims up to 6 hours of Internet use, or up to 8 hours of talk time. We didn't measure closely, but our first day appears to bear out these claims. It will take a few weeks of use to get a sense of how long the battery lasts with typical a day to day usage, but we guess that we'll be charging it every two or three days as we drop to less frequent use.

Unlike the majority of mobile phones which have a battery that is easy for an end user to replace, the iPhone does not compromise the sleek design with a battery "bay" or a "sliding" rear cover.

EveryiPod.com was optimistic that it would be possible for a technically minded end user to replace the iPhone battery -- without resorting to soldering -- in the same way many "full size" iPod, iPod mini, and iPod nano batteries can be replaced with a good deal of effort, but unfortunately, upon disassembly, the always excellent iFixit discovered that the battery is soldered to the logicboard.

Nevertheless, for the patient and highly technically inclined, iFixit has released step-by-step instructions for desoldering the existing battery -- and soldering a new one in its place -- as well as instructions to replace other parts in the iPhone. GearLive also has released a video tutorial of the same battery replacement process.

Obviously, replacing -- or attempting to replace -- the battery in the iPhone yourself could damage the hardware and voids the warranty.

After the one year warranty, Apple offers to replace the battery for US$79 plus US$6.95 for shipping. The service takes three business days and a "loaner" iPhone is offered for US$29 while the battery replacement is in progress.

Also see: How does the battery life of the iPhone 3G compare to the original iPhone in real-world tests? Can you replace the battery in the iPhone 3G?