Honor is reportedly testing a phone with a 14,000-15,000mAh batteryThe main selling point of the handset would apparently be a "guaranteed" week of battery lifeHowever, we wouldn't count on being able to buy it even if it does launchAfter having remained relatively stable for a long time, battery capacities in smartphones have finally started increasing over the last few years, thanks largely to the use of new technologies such as silicon carbon. But mainstream handsets still tend to be under 6,000mAh, and very few phones breach 10,000mAh.That could soon change though, as Honor is reportedly testing a phone battery of between 14,000mAh and 15,000mAh — with the phone’s main feature supposedly being a “guaranteed” one-week battery life.This is according to leaker Digital Chat Station posting on Weibo (via NotebookCheck), which has a reasonable track record — but we’d still take this with a pinch of salt.The right brand for the jobThe Honor Win RT 2 (Image credit: Future)If any company was going to do this, Honor would be a likely candidate, as this brand has already launched the likes of the Win RT 2 gaming phone with a 12,070mAh battery. So making a phone with a 2,000-3,000mAh higher capacity doesn’t sound impossible, but it might lead to quite a weighty, chunky handset, or mean compromising other specs.As NotebookCheck points out, it might also require more complicated thermal management, so there are likely to be challenges in delivering this.Still, there could be a market for it, particularly for people who spend a lot of time off-grid or simply use their phones a lot. With the right MagicOS optimization, that one week of life claim could well hold up given that 15,000mAh would be triple the capacity of the Samsung Galaxy S26 Ultra — a phone which delivered “fantastic” battery life according to our review.That week-long battery life would also take Honor's smartphone into the kind of feature phone territory that many of is remember getting from our classic Nokia phones. Although current Nokias, like the Nokia 300 Charge, promise 40 days of standby time and even have a power bank for charging other gadgets.It isn't clear if Honor's phone will come with these kinds of features, and for now we wouldn’t count on seeing it launch globally. Even if Digital Chat Station is right, it only only says that Honor is “testing” it, and even if it launches, it might only be sold in China. Still, if Honor shows that it’s achievable without making the phone ridiculously chunky in the process, it’s possible that other brands will follow suit.