Apple launched a battery replacement program for iPhone 5 units last August, for “a very small percentage” of users that suffered shorter than normal battery life. The affected units were sold between September 2012 and January 2013:
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.
The company updated their iPhone 5 Replacement Program page this afternoon to extend the program. Previously, the program said it would cover iPhone 5 batteries for “two years after the first retail sale of the unit or until March 1, 2015.”
The line on the page now reads “The program covers affected iPhone 5 batteries for 3 years after the first retail sale of the unit.” Three years from the affected date range puts the extension to September 2015 and January 2016.
You can check to see if your iPhone 5 is affected by entering your device serial number (go to Settings > General > About on your device to get your serial) on this page. The program is available worldwide and also includes support for Canada.