CUPERTINO, Calif., Sept. 5 (UPI) -- Apple filed a new patent that suggests the company is developing fuel cell technology to power their mobile devices.

The patent was published by the United States Patent and Trademark Office (USPTO) and described as a "fuel cell system to power a portable computing device."


The patent makes a reference to the MagSafe connectors used in Apple's MacBooks, meaning the company may seek to use fuel cells to allow their devices to last for several days or weeks before needing a recharge.

Unlike lithium-ion batteries, fuel cells combine an oxidizing agent such as oxygen with a fuel such as hydrogen to produce electricity and emit a negligible amount of heat and water vapor in the process. They can produce more energy than lithium-ion batteries of the same size. Apple's patent includes several potential fuels, including sodium borohydride, water, lithium hydride and others.

A downside of the technology is that it makes use of disposable cartridges that have to be removed and replenished once they run out of juice, presenting a potential inconvenience to users accustomed to plugging in at the end of a work day. The cartridges may also be of a size not conducive to increasingly slimmer MacBoooks.

Last week, British firm Intelligent Energy was rumored to be working closely with Apple on a fuel cell system. This cooperation produced an iPhone 6 prototype with a rear vent from which heat and vapor are allowed to escape. Hydrogen is replenished through a redesigned headphone socket. The firm's executives say the technology is premature, however, and not ready for sale for at least another two years.