Whether you’re talking about the iPhone or any other smartphone, one of the biggest questions is how long the battery will last. Now a U.K.-based firm claims to have developed a battery powered by hydrogen that can allow iPhone users to go a week between charges.

iPhone Charge Could Last A Week With This Battery Tech

iPhone battery that lasts a week?

Christopher Williams of The Telegraph reports that Intelligent Energy has built an iPhone 6 prototype that has its patented technology, which combines oxygen and hydrogen to create electricity, producing only a small amount of heat and water as waste. The iPhone 6 prototype also has a rechargeable battery.

Although it’s unclear whether Intelligent Energy is working with Apple, Williams reports that the two are believed to be partnering on this project. The company claims its technology is the first in the world to incorporate a fuel cell system into the iPhone 6 without changing the shape or size of the phone. The only change in the design of the smartphone is the addition of vents on the back so that a tiny amount of water vapor is able to get out.

Revolutionizing smartphone batteries

According to The Telegraph, an adapted headphone socket refuels the hydrogen gas inside the prototype iPhone 6. Intelligent Energy plans to sell the technology as a disposable cartridge that fits into the bottom of smartphones. The cartridges will contain a powder that releases hydrogen, and each cartridge would have enough powder to allow a “normal” amount of use on an iPhone for a week without having to recharge it.

The technology firm is reportedly considering how much to sell the fuel cell cartridges for, and Williams states that experts believe they will sell “for the price of a latte.” They also estimate that the new technology could create a market of up to £300 billion per year.

Of course it will be a few years before we start seeing this technology in smartphones, as it requires smartphone manufacturers like Apple and Samsung to build the cartridge slots into their phones. Intelligent Energy finance chief Mark Lawson-Statham noted that we’re still a few years away from their technology being in use, but he hinted at the existence of a partnership with an unnamed company, stating, “Really it’s about how quickly does our partner want to press the button and get on with it?”