I think you are confusing amps for EVSEs and breakers. Hard wired EVSEs are usually 48A which requires a hard wired 60A breaker (80% of 60 is 48).I agree with you: 9360 w/h / 240V = 39 Amps. If so, then I could just plug it into my existing 50 Amp circuit (with 50 Amp circuit breaker) without hardwiring it. 40 Amp EVSE are at least $100 cheaper than 50 Amp EVSE, which require hard wiring. If the onboard charger is 50 Amp, I'd rather use 50 Amp EVSE, which would require hard wiring and 70 Amp circuit breaker (70 Amp X 80% load = 56 Amp). I'm ready charge by pluging in, but I can easily hard wire it as well.