New Apple batteries could last for weeks, as company files patent for new fuel cells for MacBooks and iPhones

Instead of needing to plug back into charge, users could just swap in a new battery pack, according to new documents

Apple is working on batteries that could power its MacBooks and iPhones “for weeks”, according to new patent documents.

The company has detailed new plans, apparently for its laptops, that could use a “fuel cell system” to dramatically expand the battery life of the devices. And when they have run out, users could just swap them out for a fully charged one.

The plans relate to a technology that could keep laptops going “for days or even weeks”.

Apple doesn’t suggest exactly how the fuel cells would work, apparently keeping its options open for a range of technologies that are currently being developed.

The battery packs would be “a fuel cartridge which is detachably affixed to the fuel cell system”, according to the documents, meaning that they could be taken back off and either charged or thrown away when they were finished with.

The document says that the would be made up of at least one of: “sodium borohydride and water; sodium silicate and water; lithium hydride and water; magnesium hydride and water; lithium borohydride and water; lithium aluminum hydride and water; aluminum hydride; an amine borane complex; a hydrocarbon; lithium aluminum hydride; magnesium borohydride; a magnesium borohydride-amine complex; compressed hydrogen gas; and liquid hydrogen.”

But the filings do make reference to Apple’s MagSafe charging system – the technology used on most of its laptops to let the chargers magnetically clip on, and then slip back off if pulled so that tripping over the wire won’t bring the computer crashing back down. That likely means that Apple is considering the technology for use on its laptops, though it could also indicate that it is planning to bring similar connectors to its iPhones and iPads

The battery packs would be “a fuel cartridge which is detachably affixed to the fuel cell system”, according to the documents, meaning that they could be taken back off and either charged or thrown away when they were finished with.

Apple files a huge number of patents, many of which never actually make it to market. But Apple and other smartphone and computer makers are well known to be working hard to improve the battery life of their devices – trying to fix what is regularly customers’ biggest complaint.