According to the TUV listing, the Galaxy S21 Ultra has a 4,855mAh rated battery capacity, and the typical capacity is 5,000mAh. Galaxy S21 series devices are expected to be more powerful than the S20 series and reported to use the latest 5nm Exynos and Qualcomm chipset. Samsung has already started firmware development for this series.
The Galaxy S21 recently appear in 3C certification with model number EB-BG991ABY (SM-G991) while the plus variant appears with EB-BG996ABY (SM-G996) model number. The listing reveals that Galaxy S21 will feature a 3,880mAh battery, whereas the S21+ will fuel a 4,660mAh battery. Most of the specifications of the Galaxy S21 series is a mystery now. We expect more details to surface online in the coming weeks.

Samsung Galaxy S21 Ultra to have 5 000mAh battery  TUV Rheinland certification suggests - 68