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,” Teresa Brewer, an Apple spokeswoman, told +The New York Times. “We are reaching out to customers with affected phones and will provide them with a replacement phone.”

The Apple iPhone 5S is supposed to have significantly longer battery life than its predecessors. But for a small number of the new models, a manufacturing defect has caused the battery to drain quickly, according to the company.
“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,” said Teresa Brewer, an Apple spokeswoman. “We are reaching out to customers with affected phones and will provide them with a replacement phone.”
Apple did not say how many iPhones were defective, but its statement implied that it was a few thousand phones. In September, Apple said it had sold nine million new iPhones in the first weekend they went on sale.
A manufacturing issue is not the same as a defective battery, which some users thought was the problem with their phones.
Apple has faced problems with defective batteries in the past. In 2006, it issued a recall for some laptops because their batteries contained cells manufactured by Sony, which were causing some batteries to explode.