Samsung Galaxy S4
Samsung Galaxy S4 Reuters

Samsung is reportedly offering free replacements for the faulty batteries in Galaxy S4 models. Last week, the tech giant had been receiving several complaints from users about "swollen" batteries with severe power drain.

"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," said Samsung in a statement, reports Trusted Reviews.

German website Mobiflip noted that around 30 percent of Galaxy S4 handsets sold in the market has been found with faulty batteries, which may take a direct hit at the smartphone sales.

Galaxy S4, which once was Samsung's highest selling smartphone, has dropped to the five million sales mark in August from seven million in June, according to Counterpoint, a Hong-Kong based analytics firm.

The firm also mentioned that besides the sales decline, Galaxy S4 still leads the race of top 10 smartphones for the month of August.

The high-end smartphone market segment is believed to be moving at a slow pace, which may prompt Samsung to shift its focus towards the mid and low-range segment.

Counterpoint stated that the sales drop of Galaxy S4 units is counterbalanced by the low and mid-range segment which includes smartphones like Galaxy S4 mini, Galaxy S Duos, Galaxy Fame and a few others.