I'm using a 14-50 outlet, 240V at 50A. That said, I'm running an adapter cable to 6-20 (
https://www.amazon.com/gp/product/B081PZCR65/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1). I also wanted a little more cable length, so I'm running a 25' 6-20 extension cord (
https://www.amazon.com/gp/product/B07TCNT8ZB/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1). I wouldn't run these adapters and extension cords if the charging rates were higher, more on that later.
I have Sense Power monitor in my house, and I do see 3-3.5 kWh used during charge. I don't believe the battery is every really empty, the usable battery capacity is 14.8 kWh, so you're really only charging 15 kWh. I've also seen that it doesn't charge at full power the entire time, it seems to taper down when closer to full. I charged completely empty last weekend, and I recall it taking about 5.5 hours.
I did prefer my Tesla's charging system, the car reported the exact amps and volts going in, a bit more nerdy of a setup. 3 kW is not a lot, less than a clothes dryer or air conditioner, and compared with majority of EVs which support fast charging, I don't think there's any risk of battery damage charging at such conservative rates. I think it's also easier on your internal house wiring and breakers. We've seen faulty wiring cause garage fires, etc. At 3 kWh, it's fairly conservative in my opinion. Our driving is usually 10-20 mile round trips, we plug it in almost everytime and it's almost always full. This car's setup and charging is perfect for us, living in interior/central Austin, I literally never use gas unless going out of town.
