Very true. But someone has to be in the home office, tracking all these autonomous trucks on the computer, monitoring all the on-board systems, routing all the deliveries. Americans should not be afraid of changes and the future. If we embrace progressive ideals our future will be bright indeed1
Yep, but that means 400 kW average to each ~ 250 kWh pack over the 30 minutes that 400 miles of range are accumulated. 400 volts at 100 Amps average. Somewhere around 1.6c average Either batteries are going to get a lot better real soon, or the voltage is going up.
Agree, you probably want motor draw coming from the whole pack, as well as regen going into the whole pack, since each motor can have different levels of power flowing through them at any point in time. You would end up with unbalanced packs if each motor was wired to a specific pack. Though I guess that's less of a concern if each pack is charged individually.
Exactly, and that is why we need more dedicated, educated, imaginative, inspired young people of both genders and in between in the science discipline.
I am just a simple "complete enthusiast", I would be happy with just an open configurator for my model 3!
Disagree, since each motor is individually controllable, you can set them to draw the same power. Unless it is in a limited traction condition, all motors will draw the same due to SW control. While driving, the system can shift loading to balance the packs, if needed. But it wouldn't be needed since they would get balanced at the next charge.
I think it. If you have a common bus then a single inverter failure can stop the entire system. Same with a single pack failure. To have a common bus and fault tolerance, you would need 2 contactors for each motor and pack. 2x2x4 = 16, vs the 8 needed to isolate packs from a single motor. What functionality does the extra 8 contactors get you? And why do you want to have a buss that is carrying 4x the max current of one motor? For charging, doubling pins is not a reliable way of doubling current handling without lots of derating (let alone 4x pins), so charging each pack independently allows greater overall power while reusing existing mechanical and electrical components.
That's what I thought too, untill Elon said you could lose two motors and still out accelerate a normal tractor. I took from that, that all four are the same.
I'm thinking 250kW each to 4x200kWh packs with a kWh/mile around 1.3 so 1.25C. When you say voltage going up, are you speaking of the cells themselves? Stacking the same cells doesn't help the C rate.
I'd like to point out that Semi reservations are only $5000, but Roadster reservations are $50k/$250k respectively.
Both refundable. Guessing less window shoppers on the truck side of things. Add easier to vet real buyers.
The Tesla website says 'under 2 kWh per mile' If range is 500 miles then the total capacity approaches 1000 kWh and each pack ~ 250 kWh Each pack is taking 400 kW on average I just don't see how this is possible at 400v. Even 800v is a mighty stretch. Are we looking at a 1600v charging system ??
Yeah, I'm thinking its quite a bit under 2 kWh. A 40% diesel at 7 MPG is 2.17 kWh/mile and the Tesla is way smoother ~ half the drag, let's give it a 25% advantage. If we said 1.5 kWh/mile then it only needs to put 150kWh into the sub-packs. In 30 minutes that's a 300kW charge rate into a 250 kWh pack, ~1.2 C which lines up with putting 125kW into a 100 kWh pack. If the pack is 400V, that's 750 Amps. Lincoln welding says 3/0 cable is good for 650A at a 60% duty cycle. Add liquid cooling, and it's feasible. 8 of those is going to be HEAVY, maybe it has a spring loaded lift mechanism to reduce the effective weight? May have dropped a decimal somewhere...
Except that defeats the whole point of torque vectoring, which adjust the draw and regen of each motor in real time. This will be happening on each corner, not just low traction situations. Remember the S/X D models already use 2 motors on one pack, and the Rimac uses 4 motors and torque vectoring with one pack.