https://wccftech.com/galaxy-s20-ultra-battery-charges-fully-in-58-minutes-with-a-45w-charger/

The Samsung Galaxy S20 Ultra comes with the largest battery we've ever seen on a Samsung flagship at 5,000 mAh. After all, it'll need every erg of energy it can get to push the massive 6.9-inch 120Hz Dynamic AMOLED panel. Much like the Galaxy Note 10+, the Galaxy S20 Ultra also supports fast charging at 45W. You will, however, have to purchase the charger separately as the one you get out of the box maxes out at 25W. Now, another question arises. Is there any tangible benefit to using the 45W charger as opposed to the one out of the box. How long does it take for it to charge the device completely? We'll answer the first question later in the post, and as far as the latter goes, here's a Tweet by Ice Universe that should clear things up

For the current Galaxy S20 Ultra, the 45w charger can charge it to 100% in 58 minutes. Its battery is 5000mAh, so it is clear that the charging speed is faster than the Note10 +.