say you have the 85 KWH.
It’s down at 1%

you have 5 hours in the cheap bracket,

so you need to put in ( 85/5) or 17 KWH/Hour or 17 KW.

Now i would imagine the HPWC is hooked up to 2 Pole 220 Volt.

so P=IV, so 17,000/220 = 77amps. so your figures are correct.

if you have a 100 Amps breaker you are loading it at under 80% continous.
which is NEC load ratings.

not a bad sizing and probably why he has a 100 amp breaker on his main panel.

The author notes he charges at 60 Miles of range/Hour. assume the Tesla is getting about 3.1 Miles/KWH, you need about 19 KW to power that consumption. a little less if he’s doing slightly better or the HPWC is running a little hotter, for a short period of time.

Now FWIW Tesla has these fast chargers on I-5, and they are 100 KW. I don’t think they are running at 350 Amps but they could be running close to 800 Volts, right up around the arc limit.

Now people usually arent