Samsung reportedly tests 20,000mAh dual-cell silicon–carbon phone battery

Chinese phone makers have started shipping devices with 8,000mAh or larger batteries. Now, a tipster claims Samsung SDI is testing something far bigger: a 20,000mAh dual-cell silicon–carbon battery for smartphones.

Samsung usually sticks to more modest capacities in its phones — the Galaxy S25 Ultra, for instance, has a 5,000mAh battery. The leak says this new pack uses two cells, including a 12,000mAh unit that is 6.3mm thick, with the rest of the capacity provided by a second cell. The design is reportedly still in testing, and there is no sign yet of when or if it will ship in a consumer device.