According to RTT News, Apple has just issued a recall for defective batteries in the iPhone 5. Apple explains that the battery in affected models instantly drain or have to be charged more than usual. iPhone is willing to completely replace the battery at no charge to the owner, all you have to do is send it in if it falls in the defective category. Affected batteries seem to be in a very few amount of iPhones sold between September 2012 and January 2013.
If you think that your battery may be affected, you may submit your serial number on the Apple website by clicking here; https://ssl.apple.com/support/iphone5-battery/. If you have already replaced your battery for the same reason before this recall, you may be eligible for a refund.
If you have a device that is eligible for replacement but there is damage preventing battery replacement, the owner must fix the damage before it is sent to Apple for replacement.