The Galaxy S4 was launched in March, bringing a number of features including an eight-core chip, an eye-tracking system and non-touch gestures to control the screen. Samsung has not offered any sales figures for the handset, though analysts reckon that it was the best-selling smartphone worldwide in August.
Samsung Galaxy S4 smartphone seems to have let some battery issues slip through the cracks. There have been some reports since April on users forums of problems with rapid battery drain, such as one on Android Central in April who said that their new S4 discharged within an hour without any use. Similar problems were reported in May, with some users saying the phone was getting hot.
Other users have complained of the battery swelling, so that the phone doesn't lie flat. A number of users have chosen to buy replacement batteries from retailer sites - which is possible because the S4 has a user-replaceable battery.
German Galaxy S4 users with as many as 30% experiencing issues according to German site MobiFlip, Samsung has announced that it will replace faulty batteries free of charge.
Samsung said in a statement to TrustedReviews that "We are aware of this issue, which has affected a limited number of customers." It didn't elaborate on how many have been affected.
The company added: "We ask all affected customers to please visit their nearest Samsung Electronics service centre, where they can receive a replacement battery for free of charge. We remain committed to providing the best possible user experience for our customers."