Speaking to The New York Times, Apple spokeswoman Teresa Brewer said, “We recently discovered a manufacturing issue affecting a very limited number of iPhone 5S devices that could cause the battery to take longer to charge or result in reduced battery life […] We are reaching out to customers with affected phones and will provide them with a replacement phone.” It is unclear as to how many devices out there have actually been affected, but Apple’s statement seems to suggest that there are only a few and it is not a widespread problem, nor did they mention how does one check if their battery is one of the affected ones either. Either way if you are finding battery life on your iPhone is not as it should be, perhaps you could be eligible for a free replacement.