iPhone 6
Screenshot of purported iPhone 6 4.7-inch model from Marques Brownlee's YouTube video.Screenshot from Marques Brownlee's YouTube video.

Despite speculations on the release date of iPhone 6, one doubt that has been hovering in the minds of the public is whether the battery issue that could delay the launch of Apple's much-awaited flagship smartphone is being solved.

The purported suppliers of iPhone 6 battery were reportedly having a hard time working on an extremely thin yet powerful battery that could fit into the slim design of the device. However, the biggest obstacle that could derail the timely release of the smartphone is said to have been solved.

According to Taiwan's Economic Daily News cited by G4Games, the Cupertino giant has signed up with a new supplier, Simplo that has already solved the battery issue, giving a strong hint that iPhone 6 could be released as scheduled. The other supplier - Desai – is still said to be working on a battery that would fit into a flexible design of the device.

Going by the reports, two companies – Sunwoda and Simplo – have already solved the battery issue that has been threatening the timely release of iPhone 6, while the third company is still trying to meet the demands of the company. It was earlier reported that Sunwoda had solved the battery issue.

Meanwhile, no mention has been made on the kind of battery that will power the much-hyped smartphone. iPhone users have long been complaining about the short battery life of their devices, with many claiming that it barely lasts a day. A survey by mobile discount aggregator WalletHero also revealed that 97 percent of the respondents want iPhone 6 to have a longer battery life.

However, the battery expected to be seen in the device may not please the users. Forbes (via Mobile.it168) reported that the 4.7-inch model of iPhone 6 may come with a 1,800 mAh battery, an upgrade from the 1,560 mAh found in the iPhone 5S, and the 5.5-inch model may have a 2,500 mAh battery. 

The upgrade promises a 15 percent increase and the latest operating system iOS 8 may help extend the phone's battery life by giving users the option to switch off the apps, which consume more battery, but Apple fans may still want more, as the new iPhone will consume more battery than its predecessors, with the display getting bigger and screen resolution increased.

Apple rivals are way ahead when it comes to battery. Following are the battery specifications of iPhone 6 rivals:

Samsung Galaxy S5 – Li-Ion 2,800 mAh, Nexus 5 – 2,300 mAh, LG G3 – 3,000 mAh, Sony Xperia Z2 – 3,200 mAh, HTC One M8 – 2,600 mAh and Motorola Moto X – 2,200 mAh.

Apple is expected to launch two models of iPhone 6 with scratch-free sapphire crystal glass screen. The 4.7-inch variant may come with a 1920x1080p (440ppi) resolution, while the 5.5-inch model may feature a 2272×1280 (510ppi) resolution, according to KDB Daewoo Securities. Chinese analyst Sun Chang Xu claimed that the device will feature sensors that can detect pressure, temperature and humidity, and Apple Insider reported, citing analyst Ming-Chi Kuo that the smartphone might feature low temperature polysilicon in-cell touch panels, Touch ID fingerprint security, NFC and metal casing.

Chipmaker Taiwan Semiconductor Manufacturing Co. has started the production of Apple's processors - 20-nanometer A8 chip (64-bit) - that are making way to assembly plants, according to Apple Insider, which cited the report from Hong Kong. 

There are several reports on the release date of iPhone 6 with most suggesting that it would be unveiled either on 19 or mid-September.