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Model S/X deliveries drop off cliff, down 56%
- Thread starter ucmndd
- Start date
That's what I assumed. Assuming my horrendous math skills are correct, it should be ~120-125kwh (depending on buffer size).
sillydriver
Member
The riddle of the day. So 12.5% more cells in parallel. I wonder if the cells are the same? I assume they are in form factor, but is the chemistry improved? And I assume 6s means 6 serial. Vs no serial before? Are the serial cells a replacement for the low voltage battery? Six of them sounds like about 24 volts. What's that for? Hmmm...
Raises more questions than it answers in my mind. That's 132 extra cells per battery module. Assuming they keep the same nominal pack voltage of 400v, that implies 2,112 additional cells across the 16 modules. Not sure where you physically fit that many additional cells.
Current 100kwh battery is 16 modules. Each module is 6 serial strings of 86 cells in parallel, for a module voltage of ~25v. 16 modules in serial yields the overall pack voltage of 400v.
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sillydriver
Member
Got it. "s" is strings, not series. So more cells for more range, but what I like even more than that is more cells in parallel. So more current by a factor of 108/96 and more motor power, baring limiting current in software. Unless, of course, the whole thing is heavily rearchitected so there are only, say, 14 modules.
Ah.. cool! So what does that imply about cell module and pack construction? The voltage hasn’t changed, so there are no more cells in series.
The Y is taller than the Model 3, but the same footprint. So the pack can't be any bigger. If you take a Model 3 chassis then stretch it and widen it to the same dimensions as the S, you get more space for batteries. That would create an up market where if you wanted the ultimate touring Tesla, you had to buy an S. With a bigger battery pack the Performance S would also be much zippier than the performance 3.
There would have to be some interior additions to justify the higher price too. The standard S would still have to be about $10K-$15K more than a long range Model 3.
Most manufacturers are going to one, or a few platforms for all their cars. Cars have been stretched for decades. The chassis the late 70s and 80s Cadillac deVille was built on was the same chassis as the Chevrolet Impala/Caprice with a section added behind the B pillar to give more backseat legroom. The Buick Park Avenue and Oldsmobile 98 were also built on the same stretched chassis.
Now car companies are taking one basic chassis and stretching and/or widening it as necessary. It saves a lot of expense in manufacturing, as well as providing spare parts. The Model 3 is the most advanced platform Tesla has, so it makes sense to use it as the standard for future development until they come up with the next generation platform.
If I was on the design team I would have advocated for making the platform extendable for a next gen S/X.
The energy rating of the pack as well as the amount of power that can be delivered at any moment is dependent on the total number of cells and the capacity and rating of each cell. The number of cells in series determines the voltage, but the current is determined by how many groups are in parallel. Batteries in series can only provide the current of the weakest cell in the string. So if a single cell can safely provide 1A, at 4V, putting 6 in series will get you a string that can provide 1A at 24V. But put 10 of those strings in parallel and you get an array that is still 24V, but can provide 10A.
Putting cells in series adds up the voltage and putting them in parallel adds up the current capability.
There are trade offs. Higher current requires heavier cabling, but higher voltage requires better insulation. The higher the voltage, the easier it arcs. That's why you get a static shock sometimes. Your body builds up a charge and arcs to a metal object, but in that case the voltage is very high, but the current is tiny, so while it may hurt, it doesn't do any damage.
Right. I’m an electrical engineer so I get all that. My question is what does the 108 mean? If it implies 108 in parallel then that means fewer modules. Unless they’ve changed something in the chassis to make more room, which I doubt. Or perhaps it means that we’re now seeing the 2170 pack, where there are fewer modules, arranged differently?
Interesting.
Fewer modules means lower pack voltage, which I just don’t see as feasible given supercharger v3. No way we’re going back to 350v or lower packs.
Like I said, more questions than answers...
OK, there is a wide range of understanding on this forum.
I know the original modules (85KWh and 90KWH) were 6s X 74p. I forget how many are in the 100 KWh pack, but I think it's something like 80p. 108p is a big increase.
They could get away with a fewer module pack with a DC-DC converter, take 400V in, and step it down to the pack voltage. I know the Model 3 has fewer modules, but I don't know what the voltage is per module. They may be using a DC-DC converter there and a lower pack voltage.
A DC-DC converter would also allow superchargers to go to even higher voltages than they do now.
I was waiting with my Volt until the Model 3 was available, and then came the poor QC. Then Elon wanted my projected gas savings upfront as cash. That really ticked me off, so I bought a used MS so as to let the original owner take the $30K hit in 3 years, took advantage of the lifetime SC, but had to put up with an idiotic CPO business model that I will not tolerate again. Then came the screen bubbles, rattles, inoperable browser, etc. in an $80K car. But these are for other conversations.
MS sales are slow because these are expensive cars vs. less expensive M3. It's not...rocket science.....
BTW, as of tonight, for the MS, Tesla still wants $5500 of your projected gas savings and your $3750 rebate, for a grand total of $85K for the base model that should only cost $75K. I do hope the stock price stays high as future customers who are turned off to these antics turn to other established car makers.
86p.
Only 4 modules and the pack voltage is 350v - but the pack architecture is dramatically different. So I suppose it’s at least feasible that they would move the S/X to a 350v pack with fewer modules but more cells in each one - someone should do the math on that:
14 6s108p modules is 9,072 cells.
16 6s86p modules is 8,256 cells.
9% increase? Maybe plausible in the existing footprint? Dunno. My impression was that the 100 pack was already basically at max cell capacity.
I just don’t see that as feasible. Even a 95% efficient converter would throw off massive amounts of waste heat when talking about 250+kW supercharging.
It is a perplexing question. There are various ways they could re-architect the battery pack, but none really work with 6sX108p modules.
The other obvious question is, why would they bother to heavily redesign the pack around 18650s when 2170s are in the offing? It would seem to be a waste of resources.
Maybe Elon was telling the truth about retaining the 18650s? But why????
Yes, but as I've read, the agreement requiring Tesla to buy 18650s from Panasonic has expired. I really struggle to believe that Panasonic would hamstring Tesla from upgrading the cells in the S/X - especially given that Panasonic is the one that makes them in the GF anyway.
If this is what's happening, there's obviously a reason. But what?
sillydriver
Member
Yes, more questions than answers. For me the high-level takeaway is that in addition to changing motors (which seems highly probable) it looks like they are altering the pack design and possibly significantly rearchitecting the pack. If they do that to the extent of altering the way the pack physically interfaces with the car (which might be a stretch) then they would probably do any other contemplated physical changes at the same time: e.g. interior changes. Also, changes as significant as these probably wouldn't just be snuck into the production flow like typical Tesla upgrades but instead would merit an announcement and introduction. All of which makes it more likely that we will see an upgraded S presented at the analyst meeting on the 22nd.
PS - forgive the typo back in #146 where I wrote 96 instead of 86.
PS - forgive the typo back in #146 where I wrote 96 instead of 86.
I agree Sillydriver. I think we've got a fairly large update coming. But I doubt that Tesla would bring it up at that meeting unless the revised cars are rolling off the line. There is a huge risk of Osborning remaining demand for the S&X.
It's one thing for info like this to float around in an enthusiast forum. That won't affect a lot of people. But if Elon tells the general audience, that's a different animal.
I often wonder if Tesla drops obscure hints like what VG found so that we nutbars will hold off buying until the upgrade is released, while keeping quiet in the general media, so as to not kill demand. I suspect I'm giving too much credit, but who knows?
It's one thing for info like this to float around in an enthusiast forum. That won't affect a lot of people. But if Elon tells the general audience, that's a different animal.
I often wonder if Tesla drops obscure hints like what VG found so that we nutbars will hold off buying until the upgrade is released, while keeping quiet in the general media, so as to not kill demand. I suspect I'm giving too much credit, but who knows?
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