The OnePlus 15 features a massive 7,300mAh battery, while the slightly more affordable OnePlus 15R has the company's largest-ever unit in a phone at 7,400mAh.
The short answer is that OnePlus is using silicon-carbon technology.
Reducing exposure to heat also helps lithium-ion cells last longer, and the way OnePlus does that is through SuperVOOC, a charging technology pioneered by sister brand Oppo.
The OnePlus 15 and 15R can take up to 80 watts from a SuperVOOC adapter in the United States, and up to 100 watts in other regions.
All of this should mean that a new OnePlus phone should last you through your entire day for many days to come, even when you'll be jealous of those who'll be able to buy the OnePlus 20 in five years.
The OnePlus 15 features a massive 7,300mAh battery, while the slightly more affordable OnePlus 15R has the company's largest-ever unit in a phone at 7,400mAh. These batteries don't take up that much more space than the 5,000mAh-ish batteries on an iPhone 17 Pro Max, Samsung Galaxy S26 Ultra, or Google Pixel 10 Pro XL, so what gives here? The short answer is that OnePlus is using silicon-carbon technology.
Conventional lithium-ion batteries use graphite (a form of carbon) as the main capacitor material for charging. By mixing in silicon, engineers are able to design batteries with higher density and capacity. Introducing silicon also brings risks, though, such as a greater tendency to swell while charging and discharging, as well as potentially faster battery degradation. That said, with marked capacities reaching way higher than ever before, and no widespread reports of major failures, it seems as though the technology has made some quiet gains in extending the typical battery's useful life.
Reducing exposure to heat also helps lithium-ion cells last longer, and the way OnePlus does that is through SuperVOOC, a charging technology pioneered by sister brand Oppo. Whereas most other phones have power management components that can start to heat up when they get busy, SuperVOOC puts those components and responsibilities into the adapter itself.
The OnePlus 15 and 15R can take up to 80 watts from a SuperVOOC adapter in the United States, and up to 100 watts in other regions. All of this should mean that a new OnePlus phone should last you through your entire day for many days to come, even when you'll be jealous of those who'll be able to buy the OnePlus 20 in five years. But hey, at least your phone's battery might be in better shape than your friends'.
