Galaxy S27 Ultra 'Most Likely' to Feature Lineup's First Silicon‑Carbon Battery

Out of all the smartphones Samsung has planned, next year's Galaxy S27 series will "most likely" be the first to feature silicon‑carbon batteries, tipsters say.

According to the tech blog Schrödinger Intel , a Korean blogger who goes by yeux1122 reports that "Sung-Hoon Moon, Samsung's own executive VP and head of smartphone R&D, acknowledged internally that Samsung is behind on battery innovation." Meanwhile, leaked internal test documents reveal that Samsung SDI is testing silicon‑carbon packs with higher energy density than currently used graphite‑based cells, which could let the S27 Ultra over the current 5,000mAh without making the phone thicker.

Silicon‑carbon batteries still use lithium‑ion chemistry, but they add silicon to the anode to store more lithium in the same space. But past batteries that used a lot of silicon tended to wear out faster than those using graphite. This could be the reason why Samsung waited so long to implement it.

The leaked testing documents claim that Samsung SDI's test packs target around 1,500 full-charge cycles before reaching an end‑of‑life state of health. This figure was 2,000 for the S25 Ultra, but dropped to 1,200 for the S26 Ultra, per EU energy labels.

But the battery upgrade seems to focus largely on the Ultra variant, as the Galaxy S27 and S27+ could only see a modest capacity gain to around 4300 mAh and 4900 mAh, respectively. In contrast, S27 Ultra is expected to range from 5,500mAh to 6,700mAh, depending on the source.

For now, the safest bet we can place on these leaks is that Samsung hopes to bring silicon‑carbon batteries to at least one Galaxy S27 variant, and it'll probably be the Ultra.