Although the iPhone 6S is Apple's latest smartphone model, its battery capacity could end up disappointing users.

As confirmed by various sources, the Cupertino-based tech firm's newest flagship device only comes with a 1,715mAh battery.

Apple officially introduced its latest offering to the public on September 9 during a special launch event held in San Francisco's Bull Graham Civic Auditorium. Although the specs of the device were detailed during the event, Apple did not provide any information regarding the device's battery.

But recently, the company released a video of Jony Ive, its chief of design, demonstrating how the 3D touch technology on the iPhone 6S and its larger counterpart the iPhone 6S Plus works. It was then revealed in the clip that the iPhone 6S is powered by a 1,715mAh battery pack. This is even smaller than its predecessor's 1,810mAh battery, Mac Rumors reported.

As for the Plus variant of the device, it features a 2,750mAh battery, which is also smaller than the one powering the iPhone 6 Plus.

Sony, one of Apple's competitors in the smartphone race, even took a jab at the company due to the disappointing battery capacities of the iPhone 6S and iPhone 6S Plus, according to Android Authority. Mocking Apple's recent Hey Siri event, Sony tweeted, "Hey Siri, what about the battery life?"

The company even asked users to switch to Sony as its newest devices from the Xperia Z5 series are equipped with batteries that can last up to two days.

As explained by Tech 2, Apple may have been forced to equip its latest devices with significantly smaller battery packs due to their new features. Since the successors of the iPhone 6 and iPhone 6 Plus feature 3D touch technology, the company needed the extra space inside the devices to cram in additional circuitry and other essential components.

Despite the small battery capacity, Apple noted that users will still be able to use its latest devices for a decent amount of time. According to the company, on 3G, the iPhone 6S can be used for around 14 hours while the iPhone 6S Plus can last for 24 hours. In addition, Apple will include battery-saving features in the final version of the iOS 9 platform once it officially comes out.

The two devices are expected to be released along with the latest version of Apple's operating system on September 16. The iPhone 6S sports a 4.7-inch display while the iPhone 6S Plus features a screen size of 5.5 inches.