Apple Inc. (NASDAQ:AAPL)’s iPhone 5S was supposed to have significantly longer battery life than previous iPhone models, but unfortunately, some defective handsets got into the hands of consumers. Apple Inc. (NASDAQ:AAPL) confirmed the suspicion with Brian X. Chen of The New York Times on Tuesday.

Apple iphone 5s

Battery defect affects a small number of iPhone 5S handsets

According to Apple Inc. (NASDAQ:AAPL) spokesperson Teresa Brewer, they discovered a manufacturing defect which is affecting “a very limited number of iPhone 5S devices.” The defect may cause the device’s battery to either take longer to charge or just not last as long as it should. Brewer said they are in the process of contacting customers whose phones have been affected and will be providing them with a replacement.

The company did not provide any specific numbers other than the “very limited number” specified by Brewer. According to Chen, the statement suggests “a few thousand phones.” Apple Inc. (NASDAQ:AAPL) announced in September that it had sold a record 9 million iPhones over launch weekend. That number included sales of both the iPhone 5S and the iPhone 5C.

Chen notes that many users who experienced problems with battery life on their new iPhone 5S thought the battery was defective. However, a manufacturing problem with the device itself isn’t the same as having a defective battery.

Apple continues to ramp up iPhone 5S production

Apple Inc. (NASDAQ:AAPL) has been ramping up production of the iPhone 5S in order to meet demand. Analysts estimate that the device is between 2.5 and three times more popular than the less expensive iPhone 5C. Some have cut their estimates for iPhone 5C sales, but most agree that the mix favoring the iPhone 5S is good for Apple Inc. (NASDAQ:AAPL)’s average selling price. The iPhone 5C does appear to be gaining on the 5S, although it still has a long way to go before it will catch up.

He also reports that Apple Inc. (NASDAQ:AAPL) has had battery problems in the past. In 2006, the company recalled certain laptops because some of the batteries made by Sony were exploding.