iPhone 5: Battery Replacement Program Begins

Apple has determined that a very small percentage of iPhone 5 devices may suddenly experience shorter battery life or need to be charged more frequently. The affected iPhone 5 devices were sold between September 2012 and January 2013 and fall within a limited serial number range.
If your iPhone 5 is experiencing these symptoms and meets the eligibility requirements, Apple will replace your iPhone 5 battery, free of charge.
Here’s how to find out if your device is affected.
1. Find Your Serial Number
You’ll need the serial number to prove your iPhone has legitimate battery issues. To find the serial number for your phone, go to Settings > General > About > Serial Number. It is about halfway down the page.

2. Enter your serial number in on Apple’s Battery Replacement Program website

Enter the number into the Eligibility box and press Submit.
3. If Your Phone is Eligible
Visit an Apple store or an authorized service shop.