The iPad Mini 2, with or without Retina display panel, is not included with the supposed iPad 5 release date in early September 2013 but the pushback could lead to the small iOS 7 tablet's advantage over its Android rivals, a new report said.

He wouldn't mind waiting a bit more time for the second iPad Mini, according to CNET's Brooke Crothers, but all the delays should be worth the trouble. What will make the wait worthwhile is the realisation of killer features, backed up by a battery that far exceeds expectations, Mr Crothers said.

True, one of the key upgrades that the Mini 2 needs is a screen resolution that will best the 1920 x 1200 that Google and Asus have recently delivered via the Nexus 7 version 2.0. The tablet's pixel density of 323ppi is a runway winner to the underwhelmed screen attributes of the first Mini.

But there appears a huge compromise that Google failed to address prior to the Nexus 7 launch - the battery life.

In a review by The Wall Street Journal, the Nexus 7 lasted only an average of six hours on continuous video playback, the Wi-Fi radio signal active and screen brightness set at 44 per cent. Google has pledged that the tablet will remain humming for no less than nine hours.

In comparison, the first iPad Mini lasted more than 10 hours under the same condition.

That should mean that in terms of basic usability and core functions, Apple has a better compact tablet package, notwithstanding that Google packed the second Nexus 7 with upscale components, headlined by a quad-core CPU and a high-end GPU that fires up the Retina-like screen rendering.

It also proved that "a great display has limited value if the device can't hold a charge," Mr Crothers said.

And Apple should learn from this major Google miss that "when the device has a gorgeous display ... ultra-high-resolution displays are demanding ... they typically need big batteries to keep all those pixels lit up."

Reports have been persistent that the Mini 2 will not meet its Q4 2013 release date precisely because of Retina-related production issues. Some analysts presumed that volume production of the panel is the main problem while others offered that Apple is still solving the mystery of having an immersive tablet screen and a battery with enough power juice.

For Ming-chi Kuo of KGI Securities, the fix will not arrive anytime soon, hence for him the iPad Mini 2 release date will not occur until March or April 2014. But for Glenn Yeung of Citi Research, the likelihood is there that a rollout will happen in the latter part of Q4 2013 though Retina with the same debut is not a given.