There`s really only one choice for 45W chargers for the Galaxy S20 Ultra
(Android Central)

Best answer: Like the Samsung Galaxy Note 10+, the Samsung Galaxy S20 Ultra can charge at 45W under very specific conditions including PPS, PDO, 10V/4.5A speed, and more. Because these specific conditions haven`t been used on many phones so far, few third-party chargers reliably charge the S20 Ultra at 45W right now. Top choice for top speed: Samsung 45W USB-C Super Fast Charging Wall Charger ($34 at Amazon) Just a few minutes slower: Samsung 25W USB-C Super Fast Charging Wall Charger ($15 at Amazon) 45W on the go: ELECJET PowerPie 20000mAh Power Bank ($49 at Amazon) Why can`t I just use any 45W Power Delivery charger with the S20 Ultra? Samsung took several extra steps in the way it handles high-speed charging to prevent overheating and long-term battery damage. Unfortunately, those steps are a series of hoops that accessory makers and users like you and me have to jump through when we want to charge our S20 Ultra at top speeds. In order to get 45W charging, your setup needs to...