The smartphone market has recently witnessed a wave of devices coming from Chinese brands, equipped with batteries with a capacity exceeding 8000 mAh. However, a new leak has emerged indicating that Samsung SDI is testing a massive dual-cell battery with a capacity of up to 20,000 mAh that may completely change the landscape.
Samsung is not usually known for increasing the battery capacities in its phones. For example, its latest flagship phone, the Galaxy S25 Ultra, comes with only a 5,000 mAh battery. But, according to a recent leak, Samsung SDI has begun testing a dual-cell silicon-carbon battery with a capacity of 20,000 mAh, a number that exceeds any capacity the company has used in its phones before.
According to the source, in this test, the company relied on a first cell with a capacity of 12,000 mAh and a thickness of 6.3 mm, along with a second cell with a capacity of 8,000 mAh and a thickness of 4 mm. During tests, the battery recorded approximately 27 hours of screen operating time, in addition to an endurance capacity of approximately 960 charging cycles per year. These results look impressive on paper, especially in light of the race to increase battery capacity without sacrificing performance or safety.
However, the experiments were not completed successfully. Shortly after the tests ended, swelling was observed in the battery, raising real concerns about the long-term durability of this design. Another leaker adds that the smaller cell with a capacity of 8,000 mAh has increased in thickness from 4 mm to 7.2 mm as a result of expansion, which is enough to stop any project related to a smartphone.
It is important to note here that this information must be treated with caution, as the source of the leak is not very reliable. It’s also possible that this battery is primarily being tested for use in electric vehicles rather than phones, which may explain its size and capacity.
