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Comment by theluketaylor | Hacker News Reader

I am curious what cybertruck will charge like at existing superchargers that max out at 400V.

GM's clever solution is to present the battery pack as 2 400V packs. It does pose some very tricky pack balancing requirements though.

Other 800V cars charge quite poorly on 400V stations, usually with a hard cap at much lower than the potential max charge due to inverter limits.

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E-GMP (EV6, Ioniq5) actually charges quite fast on 400V as they run it through the motor/inverter which already pumps out more than 100kW

I think no one else is doing that at the moment.

Wait, what? They're converting their motor controller into a 400V-800V DC transformer?

yes: https://www.youtube.com/watch?v=xm4VDfdKUm0&t=719s

The E-GMP solution is also a clever one. I believe the inverter is limited to about 150 kW sustained (I think it can peak a little higher to the motors). 150 kW isn't bad but it's also a fair ways away from the 230 kW E-GMP will do on 800V.

Cybertruck does the pack splitting thing like the GM Ultium vehicles:

https://twitter.com/baglino/status/1730391023799386480

It will be interesting to see Tesla's rollout of 800V stations, so far they don't have any within their own network.

IIUC, Ultium is 400V in operation and only switches to 800V while charging on 800V units.

This sounds a little different. It operates at 800V and switches to 400V for charging.

I think that will simplify things and hopefully avoid Ultium's weird glitches during charging.

Presumably it can charge either at 400V or 800V depending on the charger it's plugged into. But I think you're right, Ultium is still a 400V drive architecture versus this being an 800V drive architecture.

True, I left out that part. :)

TBH, I'm really looking forward to seeing the Tesla tested on 800V CCS chargers via the adapter. It seems like it is at least possible that it might charge faster on those than on the current 400V superchargers.

Of course, that would change if Tesla starts enabling 800V support on V3/V4.

In the Top Gear interview they confirmed the truck can do 350kW charging on a V4 charger, 15-85% in 18-20 minutes.

https://www.youtube.com/watch?v=uefydJUbRhc @ 34min

Yeah, I saw that, but tbh, I'm taking it with a grain of salt at this point. We've already seen one screenshot of the charge rate at ~70% and it wasn't great. It was showing ~10 minutes remaining to get to 80% too. That was on a slower charger, but the charge rate was less than 80 KW.

Considering how bad the 4680 Model Y was, I'm not optimistic.

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