The Galaxy S27 Ultra battery upgrade could have been much wilder

For years, Samsung has watched rivals turn battery capacity into a numbers game while the Galaxy S Ultra line remained stuck at 5,000mAh. That figure hasn’t changed since 2020, even as 6,000mAh and 7,000mAh batteries become increasingly common on competing Android flagship phones. Now, a new leak suggests Samsung may have secretly tested its own 7,000mAh option for the Galaxy S27 Ultra, only to back away from it this time.

The 7,000mAh version was reportedly one of several prototypes. But Samsung is now rumored to be targeting a 5,700mAh to 6,000mAh battery instead, which is still a sizeable jump that could finally give the Galaxy S Ultra line the capacity boost it’s needed for years.

The claim comes from Korean X leaker kro, who says Samsung tested five S27 Ultra prototypes, including versions without the S Pen to make room for the larger battery. There’s no independent confirmation Samsung actually built or tested that configuration, but a prototype trading the S Pen for battery capacity would represent a significant departure, considering the stylus has remained a defining feature of the Ultra line.

The 5,700mAh to 6,000mAh range isn’t a new number, either. Earlier reports have already pointed to a similar battery upgrade for the S27 Ultra. Samsung is also rumored to be exploring silicon-carbon battery technology for the S27 series, which could add capacity without requiring a proportionally larger cell.

The leaker claims Samsung is weighing that capacity gain against longevity. Silicon-carbon batteries can pack more energy into the same space, but Samsung may also have to balance that against long-term durability. There’s no confirmation it’s why the 7,000mAh battery was reportedly dropped, though.

Even at 5,700mAh to 6,000mAh, the upgrade would mark a meaningful upgrade from the 5,000mAh capacity Samsung has stuck with since 2020, while rivals including vivo, OPPO, and Xiaomi have already pushed recent flagships well beyond the 6,000mAh mark.

The leak also includes images showing a more rounded design with some iPhone and Pixel influence, resembling recent renders of the S27 Ultra and S27 Pro. Kro additionally mentions a Samsung headset, unsure whether it will be called Galaxy Buds Ultra or Buds Max, but aligns with earlier reports of premium over-ear Galaxy headphones in development.

For now, the 7,000mAh figure remains a what-if tease. But if the rest of these reports hold up, the Galaxy S27 Ultra could still land its biggest battery upgrade in years.