If your iPhone 5s battery life suddenly took a turn for the worse, it may not just be you. Apple today launched a battery replacement program for some iPhone 5 devices sold between September 2012 and January 2013. According to the company, these devices may suddenly experience shorter battery life or need to be charged more frequently. As with other voluntary repair efforts, Apples put up a serial number validator for people to check if they have one of the affected units.