We fully expect Apple to release the iPhone 5S just two days after the Wednesday release date for iOS 7, on Friday, Sept. 20. Courtesy / CiccareseDesign.com

Apple may be launching a second basic iPhone model for the first time this year, but most fans are still looking forward to the true successor to the iPhone 5, the iPhone 5S.

Unlike the budget iPhone, the iPhone 5S is expected to look exactly like its predecessor, the iPhone 5, but it will arrive with top-of-the-line features and specs. That’s nothing new, of course; what most users want to know about are the features and specs that will set this phone apart from other phones, as well as past iPhones. We’ve been tracking news and rumors about the iPhone 5S for the better part of a year, but we have a much better picture of what Apple will release in the iPhone 5S thanks to the recent surge of convincing iPhone leaks and images. That said, here’s what we believe Apple users can expect from the iPhone 5S when it sees its release date later this year.

1. A7 Processor

In late June, Apple rumors site MacRumors posted alleged photos of the iPhone 5S that lined up with previously leaked photos and further illustrated the differences between last year’s iPhone 5 and this year’s iPhone 5 follow-up, in terms of specs and components. MacRumors’ photo depicts a nameless Apple-built CPU, which, upon further investigation of its chip model number, looks to be a new A7 chip rather than a modification of the A6 chip currently featured in the iPhone 5. The Apple model number of the iPhone 5S chip is APL0698; the A6 chip in the iPhone 5 was model number APL0598, and the A6X chip featured in the fourth-generation iPad was model number APL5598.

The alleged CPU for the iPhone 5S. Apple will likely release an A7 chip inside the iPhone 5S, but chose to keep major identifiers to a minimum inside this iPhone 5S prototype. Courtesy / MacRumors.com

Apple has a tradition of chip model number progression: The A5 chip, featured in the iPad 2 and iPad mini, debuted with an APL0498 model number. A modified die shrink of the A5 changed the model number to APL2498, and the tweaked A5 chip introduced earlier this year in the new Apple TV had a model number of APL7498. Several other signifiers listed on the iPhone 5S chipset show how the CPU was built in the 43rd week of 2012, or late October, while another stamp shows how the new chip was built by Taiwan-based chip foundry TSMC instead of Samsung. All of this evidence points to the legitimacy of the markings on the alleged CPU inside the iPhone 5S, suggesting this chip has never been used before and is indeed an A7 chip.

2. Upgraded Battery

For the most part, the inside specs of the iPhone 5S resemble those of the iPhone 5, but with a few minor differences. The iPhone 5S logic board is slightly narrower than the iPhone 5’s logic board to make room for new components and connectors, but we definitely noticed Apple gave its battery a slight, albeit important, upgrade. The 3.8-volt lithium-ion polymer battery in the iPhone 5S looks to have a capacity of 5.92 Whr, compared to the 5.45 Whr in the iPhone 5.

The alleged interior of the iPhone 5S features a thinner logic board presumed to make room for more components, including the rumored fingerprint sensor. Courtesy / MacRumors.com

The iPhone 5 battery, according to Apple, lasts up to 8 hours on 3G and 10 hours on Wi-Fi, and can play 10 hours of video and 40 hours of audio. We don’t know to what extent the improved battery will extend the typical life of the iPhone 5S, but given how Apple worked so hard to implement energy-saving technologies in the new Mac software, the iPhone 5S -- with the help of iOS 7 -- may get an extra hour of battery life or two.

3. New Dual-LED Flash

The new camera in the iPhone 5S. We know Apple has added dual-LED flash, but we don't know if the camera specs have changed. Courtesy / MacRumors.com

It may not seem like much, but Apple has clearly adjusted the size and shape of its rear camera LED for the iPhone 5S. Whereas the iPhone 5 featured an 8-megapixel camera with a singular circular flash module, photos of the iPhone 5S reveal a new pill-shaped dual-LED flash. But while the new dual-flash features may provide better lighting and more accurate color saturation and brightness in photos, the new dual-flash may be key to Apple’s inclusion of a …

4. Slow-motion Camera

As tipped by 9to5Mac, iOS 7 contains code for a new feature called “Mogul,” which won’t activate on the iPhone 5 due to “unsupported hardware,” suggesting the software is made specifically for a future iPhone. So in the same way Siri was exclusive to the iPhone 4S, the new Mogul feature looks to be one of the few iPhone 5S exclusive features.

But what does Mogul do? According to “analysis and testing of the code,” 9to5Mac discovered that Mogul will allow the iPhone 5S to capture video at “an exceptionally fast and precise rate,” indicating a potential recording rate of 120 frames-per-second. With such a fast frame rate, it seems like the Mogul feature in the iPhone 5S will support slow-motion video, since slow-motion effects require frames to be captured at a fast rate, which then appear slowed down when the video is replayed at a standard speed -- the video above depicts how the final product may look, using the 120 FPS video recording feature from the Samsung Galaxy Camera. With a presumably enhanced camera – the iPhone hasn’t received a camera upgrade since the iPhone 4S – this additional Mogul feature should give the iPhone 5S the “cool factor” it desperately needs. Especially since there appears to be only one other “killer” feature…

5. Fingerprint Sensor

For the greater part of a year, it’s been presumed that the “S” in the “iPhone 5S” would stand for “security,” especially since Apple urgently acquired Florida-based AuthenTec last July. AuthenTec's most prized, noteworthy product, the "Smart Sensor," is likely what Apple was after.

The fingerprint sensor may allow the iPhone 5S to automatically authenticate one’s identity, possibly negating the need to input personal data on one’s phone again and again, or even the need to remember a passcode combination. Courtesy / AppleInsider, AuthenTec

At just 3mm high and 1.3mm thick, AuthenTec's first Smart Sensor, which was announced in May (right around the time Apple upped its efforts to buy the company) crams a 500 ppi, 192x8 pixel detection matrix and all the fingerprint matching technology necessary to accurately and securely detect and encrypt data about your finger. Furthermore, AuthenTec's "anti-spoofing technology" ensures that only real fingerprints are read by measuring the unique properties of the skin on your finger and translating those traits into digital data that's then compared with the "expected [fingerprint] properties."

But that's not all. AuthenTec's technology is so smart, it can differentiate your fingers so as to associate different functions with those fingers. For example, you can use different fingers to play music, or ask for directions, or call a particular contact. Apple’s plan? Integrate AuthenTec’s Smart Sensor directly into the iPhone’s signature home button.

The fingerprint sensor may allow the iPhone 5S to automatically authenticate one’s identity, possibly negating the need to input personal data on one’s phone again and again, or even the need to remember a passcode combination. Patently Apple offers a fantastic description of how this biometric fingerprint technology in the iPhone 5S could enhance iPhone activities like e-commerce.

Apple iPhone 5S: Release Date Coming, But When?

Now that you have an idea of what Apple is planning to release regarding its next iPhone, the next question is when you can expect the release date for the iPhone 5S. Given the timetable for Apple's redesigned mobile operating system iOS 7, we fully expect to see Apple's big iPhone launch coincide with the release date schedule of iOS 7 -- specifically in mid-September.

Last year, the release date of iOS 6 arrived exactly 100 days after its June 11 unveiling, on Sept. 19; the iPhone 5 was released two days later, on Friday, Sept. 21. We believe Apple will again release its newest iOS 100 days after its June 10 unveiling on Sept. 18, but seeing how Apple wouldn’t release iOS 7 without some new hardware to go with it, we fully expect Apple has already set the release date for the iPhone 5S just two days after iOS arrives, on Friday, Sept. 20.

What do you think of these alleged features of the iPhone 5S? Do you plan on purchasing an iPhone 5S when it sees its release date later this year? Sound off in the comments section below.

Follow Dave Smith on Twitter