23P and 25P info we knew form wk057 already, the real news is 31P in small pack, combining with info form EPA filling it means 80,5*31/46 = 54.25kWh or if we used 78270 Wh END-SOC small would be 52750 Wh
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C rate is higher on the 2170s while supercharging, so I'd say that's an improvement.
Elon never said this at all. He simply said they weren't optimizing 2170s for performance, they were optimizing for cost. That's not to say greater performance wasn't a happy side effect.
Elon mentioned they weren't moving S/X to 2170s right away because he still wants to sell S/X and he's worried about supply issues for the Model 3. (give it a year)
It can if you were wasting heat before. See heat pumps.
Could you be more specific, please. I know how heat pumps work, but Electrek's article doesn't mention heat pumps, only creating heat with electric motor, which has to be resistive process.
If Tesla would use heat pump, that would of course be more efficient than resistive heating.
I wonder if Tesla will still void battery warranties when they are exposed to 22F for 24 hours or more.
I got the sense (maybe wrong) that most of the heat was generated through internal resistance in the pack itself? That would be just as efficient as resistive heating. If additional heat generated in the motor / power pack could be recycled back via the cooling system, then that could potentially be pretty efficient overall.
Sure... but WHY would better performance be a side effect? The ratio of surface area to mass drops, and so you can't get the heat out as quickly. And I imagine that that's one of the factors that limits performance.
In case anyone is curious, here's the general layout of a Tesla heat management system:
All loops except for the bottom left (#103) are glycol; #103 is refrigerant. Circles with Xs in the middle (155, 157, and 159) are actuated valves. 131 is an expansion nozzle. 117, 141 and 149 are pumps. 125 is compressor. The key element is #133, a multi-loop heat exchanger. The short of it is, this system allows the vehicle to shunt heat as needed from any part of the vehicle to any other, or to radiate it away.
With M3, they're removing #143, the pack heater. Instead, they're burning energy doing nothing in the first loop (#101), with the valves open and heat pumped into the heat exchanger so that it can then warm the battery loop.
I wouldn't be surprised if they're also removing #161 (heater). That loop (#107) is the cabin heating / cooling loop, and the heater there is to provide cabin heating, since relying on the battery heater (#143) would be A) too slow, and B) potentially require heating the pack too much. But now that the motor loop (#101) is acting as a high-power heater, they shouldn't need the heater #161.
All loops except for the bottom left (#103) are glycol; #103 is refrigerant. Circles with Xs in the middle (155, 157, and 159) are actuated valves. 131 is an expansion nozzle. 117, 141 and 149 are pumps. 125 is compressor. The key element is #133, a multi-loop heat exchanger. The short of it is, this system allows the vehicle to shunt heat as needed from any part of the vehicle to any other, or to radiate it away.
With M3, they're removing #143, the pack heater. Instead, they're burning energy doing nothing in the first loop (#101), with the valves open and heat pumped into the heat exchanger so that it can then warm the battery loop.
I wouldn't be surprised if they're also removing #161 (heater). That loop (#107) is the cabin heating / cooling loop, and the heater there is to provide cabin heating, since relying on the battery heater (#143) would be A) too slow, and B) potentially require heating the pack too much. But now that the motor loop (#101) is acting as a high-power heater, they shouldn't need the heater #161.
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C-rate is still debatable, and if it really improved then only very slightly. Someone should test a 75, those aren't charger limited, I think.
And Elon said the S and X aren't getting the 2170s because they were optimized for cost, not performance. So if increased performance would have been a side effect, then his statement wouldn't really make sense.
I've never heard Elon mention supply issues, only the above mentioned worse performance. So either he didn't really tell the truth, which wouldn't surprise me, to be honest. Or the 18650s just are better for performance.
The EPA filings for KWh make more sense to me, too, than the Elon quote of 50 and 75.
If it has lower internal resistance the generation of heat has a different profile.
Debatable I guess, but in the video you posted we do see what percentage it reaches at the 30 minute mark and if Tesla's numbers (for range and miles/30 min) are to be believed then it's a 7.5% improvement.
100 * ((170mi / 310 mi) / 0.51 - 1) = 7.5
In case anyone is curious, here's the general layout of a Tesla heat management system:
The short of it is, this system allows the vehicle to shunt heat as needed from any part of the vehicle to any other, or to radiate it away. .
Isn't cabin heating only resistive? Meaning that car cant use waste heat from motors to cabin heating?
Which would only be possible with an improved chemistry; improved enough so that the drop in internal resistance is enough to offset the added heat removal challenge.
If their priority is $/kwh and reliability/durability, then it further stands to reason that they wouldn't be taking any risks on a significantly new chemistry.
We know it's a new chemistry though from comments of JB and Elon. Tesla has been working on it since 2014.
As per the patent diagram, the motor loop (#101) is directly connected when the valves are open to the cabin loop (#107). However, normally when you're running the motor efficiently, you've got a long wait for the motor loop to heat up. With M3 deliberately wasting as much energy as possible, the motor loop should heat up a literal order of magnitude faster.
That's very true. Still the cells don't seem to be better in any other aspect and charging speed was the only one never mentioned to be optimized for by EM.
He said the 18650s are more optimized for performance, but the 2170s are the highest energy density cells. So I come to the conclusion that the packs actually have more energy, than he said, or that the cells aren't the highest energy density cells.
If they were optimized for performance and charging speed that would be ok for me, too. But something like that was never mentioned.
Like I said before, I don't want to talk down these cells. I just saw the article, wanted to find out how much improvement they made and got to the conclusion that there is no improvement on energy density at all. So now I wonder why, or where my mistake was.
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