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Monkey

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Just want to say that our Model Y's heat pump design has made a big difference in efficiency for cold weather vs. the battery system behavior in our 2016 Model X. It will be interesting to see how the R1T handles extreme temperature environments and I'll be taking it to both extremes. F-150 Lightning does not have a heat pump system either. Very difficult with those pouch cell arrangements to even consider a lot of focused thermal control, which is why both Tesla and Rivian have said they will not use pouch cells. Too hard to control thermals and expansion. Pouches are easier to manufacture and can get a little better density when you stack a bunch of them into a box.
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R1S Maineiac

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Yup.

BTW, I know owners are pulling 185 up to about 35%. Seems to drop off after that. I haven't heard of any owner pulling 210 yet. I do suspect they're just being conservative with the curve to get one data.
185 isn't BAD on a 135kWh pack..... And neither is 210.

I certainly hope they crank up the juice for the Max pack, though.
 

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185 isn't BAD on a 135kWh pack..... And neither is 210.

I certainly hope they crank up the juice for the Max pack, though.
It would be pretty good on the max pack as well. You would see the higher numbers longer on the charge curve for the larger pack.
 

R1S Maineiac

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It would be pretty good on the max pack as well. You would see the higher numbers longer on the charge curve for the larger pack.
If they can tweak it so that it can give me 350kW from 5-20, then taper to 210kW up until 60%, I would gladly take that on long trips
 

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If they can tweak it so that it can give me 350kW from 5-20, then taper to 210kW up until 60%, I would gladly take that on long trips
I don't think that's even possible with 400V architecture that Rivians have. I think the max is 500 amps for CCS, so I wouldn't count on anything higher than 200kW
 

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I don't think that's even possible with 400V architecture that Rivians have. I think the max is 500 amps for CCS, so I wouldn't count on anything higher than 200kW

It's possible just some trickery of dual 400v parallel charging via reconfiguration of battery packs using the busbars. It is in fact what rivian has a patent for. We just don't know if it's real or not.
 

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Really curious about the lack of heat pump as well. Tesla went all-in on the heat pump for efficiency. Aside from the obvious “cost savings” excuse why would they forgo a heat pump?
Heat pumps are only efficient when it's mildly cold. They barely work when it's too cold (because they're essentially doing the opposite of A/C by moving heat from outside to inside—and there's just not enough heat outside).

The other problem is that heat pumps can't put out a lot of heat—they're better at long-term operation. They work well in homes when they're expected to keep a steady temperature. In a car, the HVAC might need to quickly heat an interior up 40 degrees F or more. That's why home heat pumps need backup (resistive) heat for rapid heating or use when outdoor temperatures are too cold.

So, in short, heat pumps are efficient but there's only a tiny sliver of time and exact conditions when they're effective in cars.
 
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I don't think that's even possible with 400V architecture that Rivians have. I think the max is 500 amps for CCS, so I wouldn't count on anything higher than 200kW
Little more than 200. The batteries can go a bit above 400v.
 

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My recollection is that in order to work perfectly in a wide range of climate, a heat pump was not an option as it ceased working efficiently at low temp.

The heat pump vs resistive heating may be a mood point. There may be more benefit to efficiently recuperate wasted heat from other system while driving such as from the battery.
Often the solution is also to include a resistive element that is used in conjunction at lower temperatures. More parts, so more expense, but also you get the best of both worlds for performance and efficiency.
 

astonius

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Heat pumps are only efficient when it's mildly cold. They barely work when it's too cold (because they're essentially doing the opposite of A/C by moving heat from outside to inside—and there's just not enough heat outside).

The other problem is that heat pumps can't put out a lot of heat—they're better at long-term operation. They work well in homes when they're expected to keep a steady temperature. In a car, the HVAC might need to quickly heat an interior up 40 degrees F or more. That's why home heat pumps need backup (resistive) heat for rapid heating or use when outdoor temperatures are too cold.

So, in short, heat pumps are efficient but there's only a tiny sliver of time and exact conditions when they're effective in cars.
Appreciate the primer, but counterpoint: if they are only efficient in a narrow window why did Tesla put forth the effort to add them to their vehicles?
 

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Often the solution is also to include a resistive element that is used in conjunction at lower temperatures. More parts, so more expense, but also you get the best of both worlds for performance and efficiency.
My home climate control does a hybrid heat system like that between heat pump, ptc, and gas where it figures out a combo based on an algorithm of comfort, humidity, and cost.
 

Sdvictor

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Appreciate the primer, but counterpoint: if they are only efficient in a narrow window why did Tesla put forth the effort to add them to their vehicles?
Because they’re California/Texas centric? Heat pumps are technically more efficient in most mild climate, but really don’t work efficiently below 25-30 degrees.
 

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Little more than 200. The batteries can go a bit above 400v.
Yes, but that will be at higher SOC, where I would expect some throttling on charge rate. Anyway I'm just guessing here.
 

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I don't think that's even possible with 400V architecture that Rivians have. I think the max is 500 amps for CCS, so I wouldn't count on anything higher than 200kW
This is the biggest factor and limitation with a 400V-450V architecture.

Electrify America, the largest 350kW charging network in the US is limited to 500amps. With a 400V battery, the max charging rate is 200kW. This is why companies like Porsche and Lucid are using 800/900V packs which allow for a higher charging speed (270kW+) while drawing less than 500amps (the limit of the charger).

So even if the R1T/R1S can handle a higher charging speed, the chargers themselves might be the limiting factor. Which is a bummer. A 200kW limit with a 135kWh+ pack is relatively slow compared to some of the other modern EVs. That's 0-50% in 20 minutes under perfect condition with no charging losses, and maintaining 200kW for the entire 20 minutes. Again that's not bad, but we have cars like the Taycan, Ioniq 5, and Lucid going from 0-80% in about the same amount of time.
 

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This is the biggest factor and limitation with a 400V-450V architecture.

Electrify America, the largest 350kW charging network in the US is limited to 500amps. With a 400V battery, the max charging rate is 200kW. This is why companies like Porsche and Lucid are using 800/900V packs which allow for a higher charging speed (270kW+) while drawing less than 500amps (the limit of the charger).

So even if the R1T/R1S can handle a higher charging speed, the chargers themselves might be the limiting factor. Which is a bummer. A 200kW limit with a 135kWh+ pack is relatively slow compared to some of the other modern EVs. That's 0-50% in 20 minutes under perfect condition with no charging losses, and maintaining 200kW for the entire 20 minutes. Again that's not bad, but we have cars like the Taycan, Ioniq 5, and Lucid going from 0-80% in about the same amount of time.
The limitations will also apply to slower chargers. For example a lot of states are installing Charge Point 125kW chargers (when paired). But they are limited to 200 amps, so Rivian will get 90 kW from them tops.
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