He was trying to move too fast with that and I wasnt convinced he could make a real world usable truck. There is another company that has a better design for a actual long distance electric semi. They use compressed hydrogen to charge the batteries. The truck runs on electric but is recharged by hydrogen that can be refilled fairly fast. The prototype supposedly has a thousand mile range.
https://nikolamotor.com/motor
I like Musk and what he's doing, but he needs to focus on getting the car production right and profitable before trying to jump to something like that.
Imo with big Trucks there has to be a bridge of two techs to make them work. Even diesel electric would be a viable option as a stepping stone. You could have the electeic driveline but use diesel generator to fast charge the batteries. There wouldnt be a need to reinvent the refuel networks as they could use normal truck fueling but would still lower emissions and burn less fuel.