Year-ender: Most talked-about topics on the Chinese internet

The new Apple iPhone 6S and 6S Plus are displayed during an Apple media event in San Francisco, California, in this file photo from September 9, 2015. [Photo/Agencies]

Consumers' query about smartphone's mystery power-off

US tech giant Apple Inc on Dec 2 announced the reason behind an abrupt shutdown problem that recently affected some users of the iPhone 6s.

"We found that a small number of iPhone 6s devices made in September and October 2015 contained a battery component that was exposed to controlled ambient air longer than it should have been before being assembled into battery packs. As a result, these batteries degrade faster than a normal battery and cause unexpected shutdowns to occur," a statement posted on Apple's official website said.

The company also explained in the note that this was not a safety issue.

The statement was released after China's consumer protection watchdog - China Consumer Association (CCA) - issued a query letter earlier to ask the company to explain and provide solutions to malfunctions reportedly found in iPhones.

According to the CCA, many consumers continued to complain after Apple announced a free battery replacement program for iPhone 6s users, claiming that the abrupt shutdown problem also exists in iPhone 6, iPhone 6 Plus and iPhone 6s Plus models.

On Nov 21, Apple introduced a free replacement program, to resolve recent reports of the unexpected shutdown of the iPhone 6s.