Apple's extraordinary profit has some techies asking when is the company going to spend some research and development money on building better batteries?

The company has just declared the biggest quarterly profit for any company ever - a whopping $22 billion - on the back of unprecedented iPhone sales.

More than 74 million people bought an iPhone in the run-up to Christmas.

But industry magazines say the iPhone has lower battery life than other handsets.

Stuart Miles, founder of gadget website pocket-lint.com, says part of the problem is that we ask too much of our phones, now that they're the gateway to the internet.

Lithium-ion batteries, which have been around for years, are the best at producing the most energy in the smallest form - at a reasonable price.

But the technology to upgrade them is notoriously slow moving.