Motors: The difference between and 800 and 400 volt motor is simply more turns of thinner wires in the windings, or fewer turns of thicker wires. The power per volume or per kg is nearly independent of the operating voltage.
Comments
Log in with your Bluesky account to leave a comment
Wires in the car: a clear advantage for 800V. They can be thinner and lighter. That saves a few kg. Not insignificant. But not something that would have a notable effect on any performance aspect of the car.
Control circuits: 400V semiconductors are more common, less expensive, and can conduct higher currents with lower losses than 800V semiconductors.
Given that current at 800V are half as much, this is mostly a wash for the two possible choices.
Because the limit is, in a real world practical sense, in the charging cable. An 800V fast charger can ramp to higher power levels much more cheaply than a 400V high current charger for all the same reasons the cars benefit from 800V. less metal or cooling/station = more stations (ceteris paribus)
Obviously the voltage difference alone does not itself explain the reason why an e-GMP car like the ioniq can charge in 20 minutes rather than the 30 a model 3 takes, but there are very clear economic advantages to going with high voltages rather than high current.
Comments
Given that current at 800V are half as much, this is mostly a wash for the two possible choices.