+1 on the pack weight as well. Keen to know if it has the record for pack gravimetric energy density.
That's basically all I'm asking for right now. I dont *need* to go from 90 to 100. But I'd like to know I *can*.
OK, been a busy past few days! Will try to catch up here. I did not. From the start, I intended to reuse the pack, so it was not fully disassembled. Just enough to get the information that I and everyone else has been speculating about. It's been reassembled and resealed using the official adhesive and all. There is currently only one 100 kWh pack ID in the firmware, so, I would have to say that would be an accurate assumption. I'm not 100% sure, honestly. I know for sure that the BMS is programmed to know when the fuse was "born", and thus should know when it is going to fail. Based on my analysis of the circuit and cells used I estimated roughly 7-10 years before they would need replacing. Who knows what they'll charge for doing so. I don't really have much insight into such decisions by Tesla. But, my understanding and deductions about their financial situation would make me believe that pack upgrades vs just selling a new car would not be in their best interest at this time. Every car they upgrade the pack in results in a 100% chance of that person NOT buying a new car to affect the same upgrade. However, every pack upgrade they deny results in a > 0% chance that person will trade up for an upgraded new vehicle. There appear to be no technical reasons why the new packs can't be put into ANY Model S/X, aside from the spacer/ring swap on the HV connector. I just put the 100 kWh pack into my Model X without issue. I had to modify the vehicle's config to reflect the new pack and update the firmware, but it works fine. I could just as easily had put it into my VIN 28k P85. I don't recall JB divulging that they were still 18650s, but I had assumed they would be. As for the heavy duty equipment... The launch limits only appeared to affect packs where the max current was set to around ~1600A. This would be ~21.62A per cell. The normal Ludicrous 85/90 packs are limited to 1520A, or 20.54A per cell. The P100D pack is limited to 1760A, but has more cells in parallel per group, resulting in a max of 21.46A per cell. However, the 100 module also did appear to have thicker cell bond wires when compared visually side by side with a module from an 85 pack. I would speculate that this would be more than adequate for the extra 900mA draw vs previous Ludicrous packs. The changes to the HV connector are not electrical. They appear to be to better seal the connector against water infiltration. As for the increased amperage... this is a pretty detailed topic. Suffice it to say, Tesla has been pushing the limits of the wiring significantly since day 1 of the S. However, they're not stupid and can calculate and otherwise monitor the thermal rise/stress in the wiring so they know how long they can maintain high output currents without damaging anything. The wiring itself has a NEC rating of something like ~200A in building electrical systems. However it can be calculated that the same wiring can carry 1760A for about 20 seconds before reaching max insulation temperature. Since the high currents are only bursts, this is fine. As mentioned above, there appear to be no technical reasons for not being able to do pack swaps with older cars. Additionally, I can confirm the spacer ring part required for using the newer packs on older cars does exist. It is actually installed on the P85D Ludicrous pack that I recently swapped into the yellow P85. I plan to remove it and put in on the X 90 pack sometime soon when upgrading it to a P90.
Not curious when you consider they've sometimes bent the truth and are also in the business of making a profit ;-) One example of truth bending was how easy it would be to upgrade your pack later on as battery technologies got better and prices fell. Based on what we know for a fact know from JH's excellent work, that could happen... Tesla just went back on that "advantage" they touted for their cars. I personally would love to see them sell us new packs, but allow us to keep the old ones by designing a power wall that basically was an enclosure for our old packs.. slap that sucker in the enclosure and instant 85 (okay, 81 or whatever minus degradation) powerwall pack... PLEASE TESLA make this happen!
No Tesla vehicle that has been sold to-date is capable of 400kW supercharging. I'd be surprised to see 150kW supercharging on any existing cars, let alone an order of magnitude improvement. It's just not possible.
That is due to the cells simply not being able to take that much energy at once, is my knowledge correct? Jeff
Any idea when Elon's tweet of the next generation supercharging will become a reality? From my understanding this will take a long time. Currently some supercharger stalls do not provide the full power potential compared to others at an empty station. I arrived at Bakersfield Super Charger yesterday on my return road trip from SF. Stall 2A only provided 250 miles an hour while stall 2B immediately jumped to 314. I was the only one at the station. I plan on trading in my Model X 90D in 4 years, hopefully by then we will have 5 minute supercharging and 400 mile range.
That's one of many reasons. Even if the cells could handle the power, the charge port, charge connector, and associated wiring simply can not. Let's look at it this way: Let's assume Tesla bumps up the supercharger side and can pack in 250kW supercharging power into the pack at say, 40% SoC. Well, that'd work out to something like ~750A. Well, the cables from the charge port to the fast charge contactors would be hot enough to boil water within about one minute. The cable from the car to the supercharger would be just as hot in about the same time. The pins in the charge port along with other termination points would likely be roughly double those temperatures in the same amount of time, melting the plastic around them pretty quickly, eventually causing serious problems (ie: fire). Assuming we can get around all of that, the pack cooling at 100% efficiency can maybe sap away a few kW worth of heat. Well, assuming the cells could handle it without damage, and maintained a reasonable IR, the IR of the best Tesla cells I've measured would mean there would be about 20kW more heat generated beyond the thermal system capability inside the pack. For perspective, 20kW of heat is the output of a 70,000 BTU heater (6 ton HVAC system). So, if after the first minute or so the wiring involved didn't burst into flames, and the cells don't explode, then within the next couple of minutes the pack would be hot enough to fry and egg on and likely be on fire. Nothing against Musk and his desire to bring faster charging to his vehicles, but it's just not happening with the current cars. Him giving the impression of anything else, IMO, is just wrong. The MPH charge rate thing is a bit of a joke, honestly. It's some kind of running average of power input over some unknown amount of time. The result is an artificially high number. Anyway, I wouldn't expect anything but a minimal increase in supercharger power any time soon, and only on the largest packs. I'd guess the 100 packs could be charged at a faster peak rate with a more aggressive taper, but that's about it. I'd bet it's at least two years before they even have a prototype car capable of even double speed (~250 kW) supercharging, and probably double that or more before any customer has there hands on one, and probably even longer before the stations exist in enough quantity to be useful.
I suspect that the Elon tweet stating that 350kW was "child's play" is alluding to the charger that will be required for the upcoming Tesla Semi-truck. Any Class 8 truck at 40 tons driving on a level road will require about 2-4kWh PER MILE. (I'm comparing directly to a 6.5mpg diesel truck at 40% efficient... new diesels are well over 50% efficient). To be viable, it needs to be able to go "hundreds of miles". 300 miles * 3kWh = 900kWh batteries. I suspect that means at LEAST 750kW to well over 1MW charging (Ferry boats and city buses are already over 1MW). If robots are plugging it in, I suspect huge amps with HEAVY cables. If humans are supposed to plug it in, maybe 500a * 2000v.
Have you measured how fast you can flow coolant through the pack at a nominal pressure? That number combined with the maximum allowable heatrise of the cells will give you the cooling capacity of the pack, not including assist from the AC compressor. Obviously the coolant moves at a flow rate fast enough to keep the 5.5kW pack heater from burning up, so I'd say that's an absolute floor on cooling capacity, with the actual capacity probably being several times that. Think about it this way, a 27kW tankless water heater has a flow capacity of 5GPM with something like a 30C temp rise? 5GPM is not much. Double the inlets per pack should equal twice the flow as well. We can pull out the actual equation if you have a flow rate.
I believe that would be the smartest. Why not multiple connections, just like the Acciona Dakar rally car? (But more refined of course) ob
Short range BEV's on the market right now seem to get a pretty fast charge into their tiny packs. Triple their (say 30kWh) pack into Tesla territory, and they'd take some 200kW already. Seems that 18650 cells and chemistry used by Tesla just aren't up for it. Even if perhaps they are the best compromise for getting cost, range and weight all in an acceptable window. Remember that when Tesla started using 18650's, their SUC's were quite a thing. Getting miles into a car like no other. I wonder what the 2170 cell are going to be like for charge speed. I've asked around on forums, but no-one seems to want to offer some guidelines of what one can expect from a thicker longer cell even with the same chemistry. It's a small dimensional change, so I'd not gamble on doubling charge rate based on that. But Tesla may have optimized the cell's chemistry to get that part on par and beyond the current low cost short range cars... To start off, it would be pretty awesome if a 60kWh Model 3 could accept the current SUC maximum of around 120kW. That'd be around 720kph. The 120+kW packs to be expected for S&X would then take (still just) 240kW. Who knows, Tesla might get a pretty high C rate for those 2170's so an eventual 130kWh pack can take all that a 350kW charger has to offer.
Jason, Will you be pulling a sheet apart sufficiently to test to failure any of those bond wires? I'm curious to see how they line up against your original testing. The increase in diameter should improve their performance and knowing how much should put the issue of why counters were employed to bed. I say should because debate on this site never really ends There is nothing better than a nerd with means and too much time on their hands. Thank you very much for sharing!!!
I am unsure if you are speculating that 2170's may have up to 2X better C rate based on physical construction, chemistry, or both? I wouldn't discount this so easily. In addition, perhaps the biggest one you didn't mention is cycle life. There are certainly other chemistries that can charge MUCH faster. But they also can have 10X lesser cycle life...