Apple released three premium handsets this year – the iPhone 8, iPhone 8 Plus and the ultimate flagship iPhone X.

The models have a new LCD display with 19.5:9 aspect ratio besides several feature upgraded over their predecessors (in case of iPhone 8 and iPhone 8 Plus) and boast of a wonderful camera, which is one of the best currently available in the market.

That being said, the 2017 iPhones failed to live up to the expectations on at least two counts. It was rumoured that Apple might introduce fingerprint scanner under display technology in the iPhone 8, iPhone 8 Plus and iPhone X, but Apple disappointed its fans.

Also read: Apple's 2018 iPhone X successor could be more power-packed with 10% more efficient 1-cell L-shaped battery

Now, will the 2018 iPhones — dubbed the iPhone 9, iPhone 9 Plus and iPhone X2 or iPhone Xs — have the fingerprint scanner integrated into the display? We can't confirm that, but several high-end smartphones coming in 2018 are expected have this feature. So, it will be disappointing if the 2018 iPhones do not have it.

Apple's iPhone X as seen in its official site
Apple's iPhone X as seen in its official siteApple

Another feature in the iPhone that has been troubling Apple fans is the battery. The iPhone 7 has a 1,960mAh battery, the iPhone 8 has a 1,821mAh cell, the iPhone 8 Plus has a 2,691mAh battery and the iPhone X has a 2,716mAh cell, but consumers need much more than this.

Rival products are far ahead in this department with the Samsung Galaxy S8 having a 3,000mAh battery, while the Galaxy Note 8 is seen with a 3,300mAh battery and HTC U11+ with a 3,930mAh battery.

What will Apple fans expect from as the iPhone 9, iPhone 9 Plus and iPhone X2? It's obvious: a huge battery!

It all sounds good at the moment if we are to go by the prediction of KGI Securities analyst Ming-Chi Kuo. He has said in his note to the investors that the battery capacity of Apple's upcoming iPhones with 6.5-inch and 5.8-inch displays will be increased significantly.

He said the iPhone X successor could be powered by a battery with 2,900-3,000mAh capacity, against the 2,716mAh seen in the current flagship.

But will the 2018 iPhone models house a 3,000mAh battery? We can't say at the moment, but what we can say is that Apple fans will be upset if the upcoming iPhones don't have a significant upgrade in battery.