Eventually, as the battery gets older, you’ll begin to notice that your iPhone or iPod touch has to be recharged more frequently. When you’re no longer comfortable with this, it’s time to replace your battery.
The iPhone’s rechargeable battery cannot be replaced by the user and you’ll have to send it in to be replaced. For more info on how to do this, go to Apple’s Battery Replacement Web page (apple.com/batteries/replacements.html). If you purchase your iPhone through AT&T, you can have the battery replaced by their service department. Note that, unless they are defective, batteries are not covered in the warranty. Replacements cost approximately $70-80 plus shipping and handling.