Analysts have been raising their iPhone 5 sales expectations as the rumoured 12 September unveiling of Apple’s highly anticipated device draws near.

“I expect this to be the biggest iPhone launch ever, possibly the biggest product launch ever,” Robert Baird Senior analyst William Power told Bloomberg’s Bloomberg Surveillance.

Power expressed some concern about whether Apple will be able to deliver on battery life in the upcoming iPhone, but suggests that the addition of 4G LTE capabilities and other enhancements will lead the sixth-generation model to be a success. However, analyst Shawn Lee believes Apple’s slimmer display could add 40 per cent more battery life for the iPhone 5.

Pacific Crest analyst Andy Hargreaves believes that Apple could sell more units of the iPhone 5 than previously estimated.

“Our most recent round of supply checks suggest iPhone 5 component supply is improving meaningfully,” Hargreaves wrote in a note to clients on Thursday. “More specifically, we believe yield rates from in-cell panel makers have improved, which should support increased iPhone 5 production capacity in FQ4 (September) and FQ1 (December).”

Hargreaves estimates that Apple could sell an additional 20 million units of the iPhone 5 than his previous prediction of 163 million. As a result, stock could reach $750, he wrote.

Apple could ship up to five million units of the iPhone 5 in the September quarter, plus 20 million current iPhone models, Hargreaves believes. He thinks that a further 50 million will be shipped in the December quarter, up from his previous estimation of 43.2 million.

When discussing the rumoured iPad mini, Hargreaves revealed that he predicts Apple will ship 10 million units of the tablet in the December quarter, following its expected October launch.

“We believe Apple’s touch-panel suppliers are experiencing modest yield issues trying to improve the glass-film touch panels for the anticipated 7.85in iPad mini,” he wrote. “However, these do not appear significant enough to drive anticipated supply below our expectations.

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