Two recent patent applications by Apple indicate the company is looking at developing a hydrogen fuel cell system to complement the rechargeable batteries in a "portable computing device" - which could refer to Apple's range of mobile iDevices, its MacBook range of notebooks - or both. The applications say the technology could potentially power portable electronic devices for "days or even weeks," which would be sure to silence critics and users who have long complained about the poor battery life of not just Apple's, but all mobile computing devices.

Despite improvements in battery technology in recent years, as well as more energy efficient chips, poor battery life continues to be the bane of the mobile gadget lover's existence. The idea of using hydrogen fuel cells to power portable devices isn't new. Horizon's MINIPAK and Toshiba's Dynario that extend the power of portable devices have been on the market for a couple of years now. But despite being portable, they aren't exactly small enough to be integrated into a mobile phone unless a return to the days of the 80s-style "brick" is on the cards.

One of Apple's patent applications says its fuel cell design would be capable of both providing power to and receiving power from a rechargeable battery, which "eliminates the need for a bulky and heavy battery within the fuel cell system, which can significantly reduce the size, weight and cost of the fuel cell system." Such a system could also offer instant refueling by swapping in a full fuel cartridge instead of waiting by an electrical outlet until a battery recharges.

Both patent applications were published by the US Patent & Trademark Office on December 22, but the first, entitled, "Fuel Cell System to Power a Portable Computing Device," was filed in August 2010, while the second, "Fuel Cell System Coupled to a Portable Computing Device," which was a continuation-in-part to the first, was filed in April 2011. This suggests Apple has been working on a replacement battery technology for some time - and they definitely aren't the only ones.

If and when hydrogen fuel cell technology makes it into mobile devices is still anyone's guess. But those salivating at the thought of a mobile phone or notebook computer that can operate for days or weeks without a recharge and can be refueled in seconds will be hoping it is sooner rather than later.