Fresh reports of overheating and batteries losing life quickly have surfaced for new Samsung Galaxy Note 7 units after exchange for the handsets began earlier on Monday in South Korea following its recall, according to South Korean broadcaster YTN.
YTN interviewed multiple customers who received new phones and complained that the phones' batteries quickly drained and overheated. But there have been no reported fires or explosions, unlike with the initial batches of the Note 7.
A customer, surnamed Choi, claimed that his Note 7 lost a percentage point in power every second, despite the battery indicator showing the thunder label during charging.
"I've charge it [Note 7] all night after the battery went below one percent, but it didn't charge over 10 percent," Choi told the news.
Broadcaster YTN conducted its own investigation, which showed that a phone charged 75 percent actually lost battery power to 49 percent once it was jacked to a charging wire after 39 minutes.
The phone's own battery usage graph showed that charging was inconsistent, the news said.
Another customer, surnamed Lee, said he took out his Note 7 with the battery charged at 90 percent, but the battery quickly fell to 50 percent and overheated.
All the devices, when taken to Samsung's service center, were recommended for another exchange.
Samsung said it received the complaints and is investigating the matter.
A spokesperson for Samsung told The Wall Street Journal that the issue is "completely unrelated to batteries", calling the incidents "isolated cases" related to mass production issues, adding that the company was conducting "close examinations" of the issue.
Samsung was unavailable for separate comment.
It is not yet known if the incidents are isolated to South Korea or worldwide.
The South Korean tech giant has extended the refund period for the phone to the end of September, and it has been ordered to conduct X-ray testing for new batteries.