Furthermore charging cables are locked while charging. (The latch is on the cable for CCS, and the latch is inside the car for NACS.) Unless the lock mechanism is mechanically broken, it's impossible to unplug a cable that's charging.
P.S. NACS is just CCS with a different connector.
Heat dissipation is a factor of amperage (solely) in the wire, and higher voltage means lower amperage for a given amount of power. Literally.
[https://en.m.wikipedia.org/wiki/Ohm%27s_law]
The challenge here is that above a certain voltage, insulation gets prohibitively difficult (and bulky), which makes solid state electronics to control and manage it also prohibitively difficult. And leakage current becomes dangerous.
For example, we could run chargers at 1 million+ volts, and use standard 12 awg stranded cables to do it with very low losses (and low heat) at megawatt charging rates.
But the insulation would be crazy thick (inches?) and if there was any damage or minor leakage, it would be very dramatic very quickly. Like ‘mini nuke’ type arc flashes. And because the distance you can strike an arc in air with 1 million+ volts is measured in multiple feet.
But agree with the rest. Regardless of voltage and current, you still need half-megawatt delivery somehow.
> The voltage range was increased to 1000 V and it supports up to 615 A (charging cable) / 1000 A (charging pole) for power delivery.[14][15] However, they are currently software limited to 250 kW.[12][16]
v4 charger already features thermally conductive liquid to dissipate heat. Maybe one could get rid of cables and car could park near charger and some serious metal rods could automatically connect somewhere under the car.
Anyways, that 1000Vx615A already supports 615kW so very close as far as we consider cables/connectors.
Anyway, if you’re just interested in big connectors/cables MCS targets up to 3.75 multi megawatts for commercial vehicles. https://en.wikipedia.org/wiki/Megawatt_Charging_System
Though 3.7MW is mostly theoretical there’s already 700kw chargers in the wild. The cables end up thick, but they can be supported by an overhead gantry which helps.
Why stop there? Heat management is the key limitation.
80 kWh / 0.8 = 100 kWh
To charge in nine minutes:
100 kWh * 60 min/hr / 9 min = 667 kW
A 400 V DC setup is common for this sort of application, so:
667 kW / 400 V = 1667 A
How physically large do the cables and related apparatus need to be in order to deliver this sort of current? What sort of training and personal protective equipment will people need in order to plug and unplug these cables? (Hint: Arc flashes are no joke!) What sort of service would you need to order from the electric company to be able to power just one of these installations?