Huawei, China's largest cellphone manufacturer, is releasing a phone that can be thought of as the inflight refuelling system of the mobile world: it can be used to recharge other phones.

The Ascend Mate2 has a 6.1-inch screen, making it more than twice as big as an iPhone 5.

The huge size of the Ascend Mate provides space for a large battery, with roughly three times the amount of energy stored in an iPhone battery.

Huawei claims it will last for 3.5 days of "normal" usage, or half that for heavy usage. Through a USB port, this battery can be used to charge smaller phones.

It has a 13 megapixel rear camera and a 5 megapixel front camera.

The phone comes in two colours - Black and White.
It is powered by a 1.6 GHz quad-core CPU and runs Android Jelly Bean OS.

The smartphone features power saving technology that improves performance by more than 30 per cent compared to other smartphones in its class, said the company.