A tipster known as phonefuturist claimed on Twitter that Samsung SDI tested a dual-cell silicon-carbon battery with a total capacity of 20,000mAh. The battery consists of a 12,000mAh cell and an 8,000mAh cell.
The test reportedly delivered 27 hours of screen-on time and approximately 960 charging cycles over a year. However, the 8,000mAh cell experienced swelling, increasing its thickness from 4mm to 7.2mm. This issue suggests the battery would not endure long-term use.
As a result, a Galaxy phone equipped with a 20,000mAh battery appears unlikely in the near term. The tipster shared images purportedly showing the batteries.
The leak’s reliability remains uncertain, as the source lacks a established track record. Another tipster with a mixed history corroborated the swelling details. Samsung SDI may be evaluating the technology for automotive applications rather than smartphones.
Recent Android flagships from Chinese manufacturers feature batteries from 7,000mAh to 10,000mAh. HONOR recently launched phones with 10,000mAh batteries.
Silicon-carbon batteries boost capacity through higher silicon percentages, though this can affect stability. The OnePlus 15 includes a 7,300mAh battery with 15% silicon content. A realme prototype boasts a 15,000mAh battery using 100% silicon.
Samsung SDI’s tested battery could incorporate a higher silicon ratio than current commercial smartphone batteries. The company has been contacted for comment on the claims and whether the test targets smartphones. An update will follow any response.



