iPhone 5S
File photo of Apple iPhone 5S being displayed at an Apple shop in Tokyo's Ginza shopping districtReuters

Even as speculations on the release date of Apple's upcoming flagship smartphone iPhone 6 continue doing the rounds, a new report has hinted at a late launch for the bigger model.

Apple Inc. is expected to launch two variants of iPhone 6, a 4.7-inch and a 5.5-inch model, though the company has not made any official announcement yet.

The Cupertino giant may delay the release of the 5.5-inch iPhone 6, dubbed iPhone Air, as it is finding hard to find a battery slim enough to fit into the ultra-thin design of the device, according to Taiwan's Industrial and Commercial Times (Google translate).

Considering the design of iPhone Air, the battery should be 2mm (0.08inch) or less, as against 2.8 to 2.9mm seen in usual smartphones, reported Industrial and Commercial Times, citing sources from the industry. It added that cutting down the size of the battery by one third could lead to a delay in the launch of the device, which could even be pushed to 2015.

A research note from UBS Managing Director Steve Milunovich (via Barron's) had earlier suggested that the 4.7-inch variant of iPhone 6 would be launched either in August or September but the 5.5-inch model may or may not be released at the same time. Reuters also reported, citing sources from the supply chain, that the 4.7-inch model would be unveiled this autumn, and the 5.5-inch version a little later.

However, Apple is expected to unveil the 4.7-inch model this fall as speculated. Nikkei claims the device would be launched as early as September.

The bigger version of iPhone 6 is expected sport a 5.5 inch display with a 2272×1280 (510ppi), powered by the A8 chip (64-bit) and run on iOS 7.2, according to South Korean brokerage KDB Daewoo Securities. It is also expected to come with full scratch-free sapphire crystal glass screen.

Chinese analyst Sun Chang Xu claimed through a post on her Weibo page, citing a friend from MEMS (microelectromechanical systems), that Apple is planning to introduce sensors that can detect pressure, temperature and humidity.

(Ed: VP)