After a batch of returns of Galaxy S4 smartphones Samsung is now offering a free battery replacement for those with a problem.

According to reports in Germany 30 per cent returns from users who bought the phone have occurred on one carrier. Samsung says it was aware of the issue.

Now Sammy has issued the statement, as reported by Trusted Reviews: "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".

Many users have suffered fast power drain and in some cases even swelling of their batteries. Since analysts believe the S4 was the best-selling smartphone in the world in August, that's a lot of faulty batteries, although Samsung won't give a figure. But some users have been complaining of a discharge in just an hour's use.

If you're one of the afflicted visit the Samsung UK website to find your local service centre.