Apple is reportedly preparing to debut two new iPhone devices this year, one with a 4.7-inch screen and one with a 5.5-inch display, according to rumors that have circulated for a couple of months.

If this is true, the larger of the two iPhones might not become available for purchase at the same time as the smaller device due to supposed production delays.

The larger device is facing production delays over its battery, according to Taiwanese news website Commercial Times.

Apple wants to equip the larger phone with a thin body, which presents a problem for battery makers, according to Commercial Times, citing GforGames.

Phone batteries are usually somewhere between 2.8mm to 2.9mm thick. The battery for the 5.5-inch iPhone would have to be around 2mm or less, according to CNET.com.

This means that production delays could cause the bigger iPhone to be released a couple months after the 4.7-inch device, or at least until battery companies can meet Apple's requirements.

The 4.7-inch device will likely become available for purchase sometime in September.

Apple suppliers have nicked named the 5.5-inch iPhone the iPhone Air, according to Commercial Times.

It is not clear yet whether or not Apple will keep the nickname, since the company usually sticks with variations of the iPhone name.

Apple has not confirmed any rumors regarding its next iPhone devices yet, including release dates, specifications, and especially screen sizes.

Other rumored specifications include: bezel-free design, improved processor and camera upgrades, and a more durable, sapphire screen. 

The new operating system that the next iPhone will likely use is expected to debut at the 2014 WWDC this June.

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