Rivian caps out at 48A (11.5 kWh) charging, which Rivian has said will provide approximately 25 miles range per hour.Why do you say that? Do you mean if you are using the Rivian EVSE or are you commenting on the CPH50 at their advertised rate with 70/80amp feeding a full 50 amp constant load?
Because different EVs consumer a different number of Watts per mile, you can't say that a specific charger gives "47 miles range" to any EV -- you must specify which EV you're talking about. Since this is a Rivian forum, using a Rivian vehicle would be most relevant. If you use a 48A+ EVSE then you're going to cap out at ~25 miles range, per hour. Even if you have a more powerful EVSE, you'll never charge faster than that (Level 2). At 32A it's ~16 miles range, per hour.