800V is not all rainbows and butterflies

[Tay Tay]

Like most of you I've read all the press about the advantages of 800V. But only just found this post and realized there are significant trade-offs:

https://www.quora.com/Why-do-so-man...tc-EVs-have-almost-identical-battery-voltages

Most interesting part:

1. More turns are needed to maintain the same torque. Torque is proportional to number of turns and current. If the current halves, number of turns needs to double. This also means your motor copper losses double, offsetting any gains you make elsewhere.
2. While you may reduce the copper cross-sectional area due to lower current (and your wire cross-sectional area reduces proportionally with current), on the other hand, the wire thickness radius changes by the square-root of the area. So if you quadrupled the voltage, then the number of turns quadruples, but the wire radius only halves, resulting in a net thicker set of coils in the motor.

Which explains why Porsche went with the square wires instead of round.

It also made me wonder, where are first responders supposed to make a cut to disable the electricity?

Sponsored

 

[Gubbjaevel]

https://www.nfpa.org/-/media/Files/Training/AFV/Emergency-Response-Guides/Porsche/PorscheTaycan.ashx