Most of us are happy just to have a laptop or smartphone that can last a full day without needing to be recharged, but that may very well change in the new future thanks to a new fuel cell that Apple is working on. According to a recent patent, the company is working on “fuel cell system for a portable computing device” that could power a smartphone for weeks. It’s an interesting concept, but it’s important to note that this is just a patent, which means it could take a while to hit the market, assuming it ever does.