ZachF
Active Member
Elon has said there will eventually be a smaller "world truck" ...think Tundra and Tacoma.
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GMC Hummer Debut 2020-10-20
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Elon has said there will eventually be a smaller "world truck" ...think Tundra and Tacoma.
Did anyone put in the preorder? If so which version? I can't get myself to for it at those prices as much as like what I've seen from the video. I know it's a promotional video and many things still need to be discovered.
Tri-motor cybertruck I pre-ordered was 69,000 and I added FSD for 7k at the time. I wonder if they will honor that or charge the 8k it costs now.
Tri-motor cybertruck I pre-ordered was 69,000 and I added FSD for 7k at the time. I wonder if they will honor that or charge the 8k it costs now.
Ruffles
Member
There were some interesting features like the camera underneath to spot the wheels and the ability to simulate locked diffs. Maybe Tesla could add cameras underneath to help with pot hole detection. I'm not crazy about the styling and with the giant battery, charging will be slower and we all know there is no charging network anywhere close to what Tesla has so road tripping will be a challenge. My biggest gripe is all the crap about it being new and revolutionary and acting like they have purposely waited to bring this out when the reality is they are WAY late to the EV game. This will probably end up being the new athlete/rapper/movie star vehicle just like the first Hummers were.
Nothing changes at the cell level. Just the charging infrastructure operates at 800V. Since the infrastructure is amp limited, higher voltage allows more power through it. So charging time can be reduced if you are infrastructure limited with higher voltage, but only up to the point where you are limited by the power intake of the individual cell.
Isnt it about how many amps the cables can take? The pack is big enough to take more amps but the cable becomes large. Higher voltage means smaller conductors. That's how I was looking at it anyway. My model 3 cable gets warm at 40amps.
ddimit
Member
Ohms Law, higher voltgae less current , smaller cables. its why if you look at your overhead power cables in your neighborhood the feeder cable feeding the transformer feeding your house (approx 12,000v) is very small compared to the 240V lines feedin individual homes
manitou820
Member
My guess is they are using a 400V architecture (I read that somewhere in the description) but the battery layout might be setup as two 400V systems. If they are roughly 100kWh per battery pack (200kWh combined) then maybe it splits the 350kW (800V at 437amps) incoming DC power and essentially charges each pack at 175kW and 400V at 437amps? I'm not sure if this is possible but it would make sense.
JRP3
Hyperactive Member
The limitation is the cell level charging rate. Until that increases nothing else matters.
Yes, it was described somewhere that the two halves can be switched from parallel to series to charge as an 800V pack.
uujjj2
Member
Honestly they don't. The actual limit to charge rate is at the cell level.
But . . . the real limit to the proliferation of fast charging infrastructure isn't technical, it's money!
A higher voltage does cut the pack-level current, which cuts the cost of the electronics and cabling needed to achieve any given charge rate. The small wires connecting up individual cells can't be made smaller, but the big high-voltage cables can. And this applies to the charging station as well. The charging station can use a thinner conductor, and smaller rectifiers/thyristors/power transistors in the voltage converter. It's just cheaper to build a 800V 350kW charger than a 400V 350kW charger.
JRP3
Hyperactive Member
Though I would expect it's more difficult and expensive to isolate and build switching components for higher voltage.
uujjj2
Member
That makes sense. With our current pack size, it shouldn't make any meaningful difference. As packs get bigger, I could see how the increased voltage would help with limiting the pack level current though.
The SAE J1772:2017 CCS maximum DC charging current is 400A. So a nominal 400V battery pack voltage limits you to ~160kW in DC charging. To get into the 300+kW range you need a higher supply voltage. (Keep in mind that losses and heat generation through a charging cable or connector increase with the square of current, which helps explain the cap on amps.)
And everything I've ever read about the rationale for moving towards 800V EV batteries (despite the increased component cost) is that it's primarily about increasing charging speeds. Until recently, most of these discussions surrounded the Porsche Taycan. But, as GM is demonstrating, other automakers are starting to follow suit.
And as for cell-level charge rate limits, considering that Tesla is able to pump up to 250kW into 75-80 kWh Model 3 battery packs with 2017-era battery tech (which works out to a >3C charge rate), I'd certainly hope that GM's hyped next-gen Ultium batteries would be able to handle above the 1.75C charge rate that is implied by 350kW going into the Hummer's ~200kWh pack.
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JRP3
Hyperactive Member
Not sure of your point. You've simply shown that 350kW going into a 200+kWh pack is not impressive. Simply put 800V charging does not provide faster charge speeds than Tesla already has.
strider
Active Member
You will lose that bet. GM has decades of history of meeting target dates. Tesla? Not so much.
strider
Active Member
Idk why everyone is fussing about charge times? The CT is going to have a >200kWh battery too. Bigger packs takes longer to charge. No shortcuts there.
I think GM was being conservative w/ the range numbers and are using today's cell tech. The CT's range number is dependent on Tesla's new cell which is still in the lab stage. I'm also reminded that Car and Driver did a simultaneous range test of a Perf model S and Taycan Turbo S and they were within 20 miles of each other in range despite a massive EPA range difference.
Overall, I think it was a good first volley into the coming EV truck wars. My disappointment was not having plugs in the bed. One of my truck's main jobs will be hauling my Alta dirtbike and I do not want to have to haul the generator ay more. They already have an AC-DC converter in the onboard charger, it can't be that hard to run it backwards.
I think GM was being conservative w/ the range numbers and are using today's cell tech. The CT's range number is dependent on Tesla's new cell which is still in the lab stage. I'm also reminded that Car and Driver did a simultaneous range test of a Perf model S and Taycan Turbo S and they were within 20 miles of each other in range despite a massive EPA range difference.
Overall, I think it was a good first volley into the coming EV truck wars. My disappointment was not having plugs in the bed. One of my truck's main jobs will be hauling my Alta dirtbike and I do not want to have to haul the generator ay more. They already have an AC-DC converter in the onboard charger, it can't be that hard to run it backwards.
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