Samsung’s Ultra models have used the same 5,000mAh battery since 2020. For six years the company has promised improvements while keeping the same cell capacity, but a new leak suggests the Galaxy S27 Ultra may finally see a meaningful battery upgrade.
According to a recent report from GalaxyClub, the Galaxy S27 Ultra is expected to ship with a battery rated at 5,534mAh. Samsung would likely present that as a typical capacity—potentially listing it as 5,700mAh or even 5,800mAh in marketing materials. If accurate, that represents roughly a 15% increase over the Galaxy S26 Ultra’s 5,000mAh battery. The report also indicates a smaller lift for the Galaxy S27 Pro, which is said to use a cell rated at 5,087mAh and marketed around 5,200mAh.
Both of those capacity increases are reportedly enabled by silicon-carbon battery technology, which Samsung has already implemented in several foldable models including the Z Flip 8 and Z Fold 5 variants. Silicon-carbon anodes allow more energy to be packed into the same physical space compared with Samsung’s older lithium-ion chemistry, so manufacturers can increase capacity without dramatically changing the phone’s dimensions.
A five-year wait, if the numbers hold
The S Ultra line has been capped at 5,000mAh since the Galaxy S20 Ultra debuted in 2020. While other brands pushed capacity higher—some Chinese flagships now offer batteries north of 7,000mAh—Samsung kept the Ultra’s battery steady across multiple generations. A move to roughly 5,700–5,800mAh would be the largest single battery increase for the S series in years. It would close the gap slightly with competitors, though it would still fall short of the largest batteries found in some rival devices.
Leaked figures are not all consistent. Some tipsters have mentioned alternative capacities such as 5,600mAh and 5,800mAh under testing, while other well-known leakers urge caution and say there’s no definitive evidence for specific numbers yet. Earlier rumors even suggested there might be no capacity change at all this generation. Of the available reports, GalaxyClub’s account is currently one of the most detailed, and several outlets are beginning to converge on similar estimates. Samsung has made no official confirmation.
Beyond battery capacity, the Galaxy S27 Ultra is rumored to introduce other refinements. One possibility is Qi2 wireless charging with stronger built-in magnets for better alignment and accessory compatibility. Additionally, the S27 Ultra may receive a redesigned camera module and other internal optimizations aimed at improving battery life, performance, and thermal management.
If Samsung does adopt silicon-carbon batteries more broadly across the S27 lineup, that could bring incremental gains in real-world endurance without a dramatic size increase. Increased capacity, paired with efficiency improvements in chipsets and software, would help the S27 Ultra deliver longer daily usage for demanding tasks like gaming, video streaming, and photography workflows.
Until Samsung publishes official specifications, these reports should be treated as informed leaks rather than confirmed facts. Still, the prospect of a larger cell in the S27 Ultra would be welcome news for users who have wanted more battery life from Samsung’s flagship Ultra series. We’ll look for official word from Samsung and hands-on testing once the devices are formally announced and available to reviewers.