A British startup claims to have solved the perennial problem of smartphone battery life, and it's used hydrogen to do it. Based on a prototype that Intelligent Energy has hooked up to a current iPhone 6, the new technology could mean a phone that lasts a week between charges rather than scraping through to the end of the day.

What makes the innovation particularly promising is that the new battery fits inside an iPhone 6 without any alterations in size or design - the only noticeable difference is a series of small vents on the back of the handset that allow small plumes of water to escape (a consequence of the controlled chemical reaction going on inside the battery). That water, together with a small amount of heat, are the only waste products from the new battery design.

The recharging process would be a little bit different, however: fresh hydrogen needs to be added via the headphone socket of the phone on a regular basis, though eventually you should be able to buy replacement cartridges rather than topping it up. It's obviously going to be some time before this technology makes it into the flagship phones we rely on today, but it's a promising development for anyone who's had their battery die on them before they made it to a power socket (which is just about all of us).

While Intelligent Energy is playing its cards close to its chest when it comes to the patented procedure behind the battery, we know that in broad terms it works by combining oxygen and hydrogen inside the thin fuel cell, with water and energy as the result. The company is reportedly teaming up with Apple in developing the game-changing battery, although neither party has confirmed the partnership.

"To our knowledge this has never been done before," Henri Winand, chief executive of Intelligent Energy, told Christopher Williams at The Telegraph. "We have now managed to make a fuel cell so thin we can fit it to the existing chassis without alterations and retaining the rechargeable battery. This is a major step because if you are moving to a new technology you have to give people a path they are comfortable with."

The Intelligent Energy team says that if all goes to plan the technology could be in smartphones within a couple of years. The idea is you would use disposable cartridges to power your phone, throwing them away and replacing them on a weekly basis.

Using hydrogen to fuel batteries isn't a completely new concept: Rohm is one of the companies that has experimented with the approach in the past, and it's also been used experimentally for spacecraft and passenger vehicles. But until now, no one has put together something that's so small, so efficient, and so easily slotted into today's smartphone devices. If the Intelligent Design prototype becomes a reality, you can toss away your phone charger for good.