I don’t know if this is normal or not. It’s really hot 90+ degrees, and I’m charging my car. I happened to go outside and heard a loud fan noise coming from my car. No indicators or warnings. Is this normal?
The BTM’s system is running and actively cooling the batteries while charging. You’re hearing the radiator fan blowing.
It could be cooling the OBC instead, or as well as the battery pack. To save a couple of threads that's 'on-board charger' It's in the same coolant loop along with the motor and battery.
be happy that you're not driving a LEAF and that the car has active cooling of the batteries. The LEAF batteries degrade 4% per year due to the passive cooling they have.