Apple's published two patent applications concerning the use of fuel cells in portable electronics. One patent application describes the potential benefits:

Fuel cells and associated fuels can potentially achieve high volumetric and gravimetric energy densities, which can potentially enable continued operation of portable electronic devices for days or even weeks without refueling.

What separates Apple’s patent applications from other portable fuel cells that are already on the market is that Apple’s can be integrated directly into the electronics. The second patent application details how Apple might be able to include an integrated fuel cell while limiting additional cost and saving on weight. The key is using the cell in conjunction with a battery; the fuel cell charges the battery and the battery charges the fuel cell. In this way, the fuel cell does not need its own battery–which saves weight and cuts cost. Will fuel cells find their way into Apple’s next generation of devices? Probably not. Apple files a lot of patent applications, and these are not the first that deal with fuel cells. What is different this time is that Apple’s previous patents have dealt with the engineering of the fuel cells themselves, not with building them into electronics. The challenge for Apple will be convincing consumers to pay for fuel cartridges. Not everyone is going to warm to adding another ongoing expense to their monthly budget.