100D or 105D speculation

[cantdecide]

I agree with David.
The S has a very low Cd already compared to other cars. Tesla went to a lot of effort and expense to get it that low. For example the door handles which save a little drag for a fair bit of cost and maintenance. Other things they did include the small rear view mirrors, the nosecone shape, the low slant on the rear and more... Overall highly optimized for low drag.
For the X Tesla tried to lower a little bit further, perhaps one percent, by removing the rearview mirrors. If they are doing that then that is further evidence they don't have many more ideas to cheaply improve aerodynamic losses. Furthermore the X looks aerodynamically similar to the S.
My conclusion is that the Cd of the X should be similar to S (barring the effect of the squarer front shape) and applied to a larger surface area should mean 20% more energy is needed aerodynamically.
For the freeway the aerodynamic energy dominates the costs, suggesting that for the highway the car should get 20% less freeway range than the SxD for the same battery.

 

[marcon]

I've said since the X was announced, it would NEED a 300 mile battery as SUV drivers are more likely to want to take longer trips. And that 100+kw battery would be available to the S when the X comes out, if not BEFORE.
Scott

I think many of us speculate from a demand perspective. I agree, that longer range would open a larger potential market for the Model S and Model X and it will be offered at some point. I also agree that people would pay good money for a larger battery pack with more range.

From a supply perspective there are several constraints:

1) Tesla is aggressively reducing possible optioning variants of the Model S to streamline manufacturing due to being supply constrained, in contrast to say Porsche, where e.g. you can mix your own individual colour. The Tesla Model S and X are built on the exact same skateboard platform, including battery layout: the Generation II platform. That is, why releasing the dual drive Model S before introducing the Model X made a lot of sense, production wise.
The space in the Model S 85kWh battery is completely maxed out. Lower capacity batteries have the same size, but do not have as many cell banks inside. Developing a completely different battery layout to sell 15-20 kWh larger batteries, would reduce commonality of parts between Model S and X.
Unless Tesla changes the battery chemistry, there will not be a larger capacity battery pack.
Furthermore, Tesla is battery supply restrained. With 1190kWh worth of cells, they can manufacture 14x 85kWh or 17x 70kWh batteries. The 70D was very likely introduced as a platform for an entry level Model X70D, making it comparable to a S60 in range and keeping comonality with the Model S.

2) Panasonic released a 3400mAh battery in 2012. They have released a 3600mAh battery since. To use the higher capacity, Tesla would need to thoroughly test the newer batteries and make possible modification in software and hardware. Is a 1/17 = 6% increase in battery size, resulting in a 90kWh highest capacity, worth that development cost to Tesla? Unless they roll that new cell chemistry out to all models they have to keep up two differnet production lines.
Considering that Panasonic might have to partially retool their production lines, currenty producing for Tesla, the production disruption and resulting amortisation costs rolled into the cell prices from Panasonic, even if low, also have to be taken into account.
The newer chemistry might also be different in how it can handle high charge and discharge levels. Maybe someone with more knowledge on the difference between chemistries and physical microstructures of those two cells might offer more information. But it means that changing to that newer cell might not be as trivial as just putting in a higher power version. (Would they be the same cells as in the 7kWh powerwall, designed for daily discharge? Does anyone know, which ones those use?)
Nevertheless, I expect no across the board change in battery chemistry until a two digit percentage improvement in energy density and/or significant manufacturing cost improvements materialise. It is very likely that the gigafactory will manufacture cells with just such a new chemistry.

3) Sales. E.g. Apple is a great example of a company releasing a continuously improved version of their products year on year (sorry, Mac Pro), enticing people to upgrade. How many people upgraded to the top trim P85D or at least a 85D, when it became available? At least from a traditional sales perspective, it won't hurt Tesla badly to offer larger capacity Model S and Model X in 1-3 years only, when technology has improved. This can also be seen in Teslas attitude to refuse S60 to S85 battery upgrades, so far. (Is even battery swap for the S60 confirmed, yet?)

 

[wk057]

How about $100 to charity? I'll take that bet.

I think it depends on how much the Model X's form costs in terms of mileage vs. Model S. I would hate to see the range reduced on the X, as there are certain scenarios that I enjoy with that range today - for example, skipping every other supercharger on a road trip saves us some time.

I'll take that bet as well. The money going to the winners charity.

*digital handshakes all around*

I can't see the Model X *not* having a range/efficiency penalty vs the Model S. It's a SUV-ish vehicle. There isn't an SUV out that has higher efficiency than it's sedan counterpart (that I know of), and IMO that's the trade off you live with making such a purchase decision.

While I believe that eventually both the S and X will be offered with better battery packs, it won't be available in the first production Model X vehicles.

 

[chriSharek]

I'm guessing that it will happen at the same time or soon after Model X battery options are revealed which will be summer or autumn. A lot of things can happen before November, not just battery upgrade. If you always wait for new features you can basically wait forever .

By the way why are you ordering now and taking delivery in November? When production of your car has not yet started there is good chance you can upgrade, at least for a small fee ($500).

Panu, my son (who inherits my Volt) doesn't turn 16 until December. It would be kind of dumb to have 3 cars for only 2 drivers in the household. But, just last night, the wife said I could take delivery September 1, instead of November, so .... I'll order on my birthday in 5 days and have it here before our Drive Electric Week event that I've been organizing for the past 5 years!

 

[blackscraper]

Your analogy about a 2.5 hour trip becoming a 3 hour trip is interesting. Even if you have a larger battery pack, your 4 hour trip will then be a 4.5 hour trip and so on and so forth. This argument defeats itself.

I am sorry I did not state clearly what I wanted to. after 4 hours, I generally would to have a prolonged break. that is when the car can have a longer charge. but model s can not drive 4 hours straight on highway thus I have to accommodate the car. I'd like a car which can accommodate me. for shorter inter city trips, such shortcoming becomes rather bothersome. for longer road trips, bigger battery means you can have less charge stops and charge at a higher rate too, which in turn,leads to a quicker road trip time. very few people regularly take meals at an interval of less than 3 hours.

 

[AmpedRealtor]

I agree with everything you said except I doubt it makes sense to offer BOTH 70 and 85. At that point either someone is going to be really frugal and get the 70D or they will want the absolute max range and will get the 1xxD. Personally I can't imagine paying $10K for only $15Kwh difference when a 1xxD option is available. I think the 85D option will disappear when the larger capacity pack becomes available.

Also it is easier for them to maintain the logistics of just 2 battery packs rather than 3.

I only included the 70 because Musk was quoted as saying the entry-level X would get the 70D battery pack. I don't have a link or citation, but it was made in the last couple of months, perhaps during the last quarterly call? Not sure.

 

[mgboyes]

There is no way they will release a more expensive vehicle whose range is below the 270 miles EPA / 310 miles NEDC of the Model S 85D.

Erm, they already did that. It's called the P85D and its EPA range is 253 miles. I hear they're selling quite a lot of them.

 

[3mp_kwh]

70 / 105. Saying that, with a look at where these arrows point:
-Range is king. Witness 40, 60 and the trend.
-$/kwh cost drop, to <$250, meaning $5,000 to offer ~40-50more range
-Tesla may be costing into production, at $250/kwh in '16, but may be realizing significantly better economies by end of year (GF).
-Insufficient "top tier" 85kwh performance, which net of area, Cd, and weight, would be anchored below ~250 rated
-Tesla buyers, and more "range" oriented people realizing faster pre-taper supercharging times (maybe 130 miles, in under 20 minutes). This comes with higher kwh.
-Higher SUV range expectations
-Being down to two battery options, 15kwh apart, makes no sense

I'd be speculating even worse, to suggest there's an economic way to add to the pack, along their assembly process. Barring excessive costs, I think we see >=100kwh this year. Cripes', look at how Cadillac wedged all 18kwh of the Volt's pack, in their upcoming CT6. It's possible. Tesla knows their customer wants it.

 

[wk057]

So far the supercharging voltages I've seen posted for the 70D suggest exactly what I had hypothesized when it was announced: 14 modules the same as in the 85 kWh pack (which has 16 modules) laid out like the modules in the 60 pack. Eliminates an entire part from production (the 60 type modules).

Nothing suggests a better cell chemistry in the 70D pack. A better cell with higher energy density by weight would be needed to get a higher capacity pack in the same form factor. You can't just add cells and weight and expect range to increase proportionally. A 105kWh pack with existing would need four more 85-kWh type modules somewhere, a weight increase of at least 25%. That weight is a range penalty even if they could find a place to physically cram it, making the car less efficient with only slightly more maximum range.

All of that said, I still am holding firm that we wont see a 100/105 pack in the near term (ie, for Model X)

 

[3mp_kwh]

A 105kWh pack with existing would need four more 85-kWh type modules somewhere, a weight increase of at least 25%. That weight is a range penalty even if they could find a place to physically cram it, making the car less efficient with only slightly more maximum range.

All of that said, I still am holding firm that we wont see a 100/105 pack in the near term (ie, for Model X)

Glad you're sticking to your guns, but care to offer what you mean by "slightly more maximum range"? At 25% more weight, I am a little rough on 85kwh pack stats but if we call that 25% 300lbs we aren't talking about a big change in the car's inertia. When we talk about "maximum range", we also aren't talking about EPA AER, MPGe City, or MPGe Highway. Those last three are all test cycles that feature accelerations. When steady on the interstate, I bet the mile per kwh gains of and extra 20kwh would still come closer to 3 miles each, than 2 (333Wh/mi vs. 500Wh/mi). No? That's where I came up with adding ~40-50 miles minimum. When you figure the i3 gets rated for ~87, on ~22kwh, we're already building in almost half the efficiency. Unless I am missing something, I think this sounds conservative.

 

[scott jones]

Glad you're sticking to your guns, but care to offer what you mean by "slightly more maximum range"? At 25% more weight, I am a little rough on 85kwh pack stats but if we call that 25% 300lbs we aren't talking about a big change in the car's inertia. When we talk about "maximum range", we also aren't talking about EPA AER, MPGe City, or MPGe Highway. Those last three are all test cycles that feature accelerations. When steady on the interstate, I bet the mile per kwh gains of and extra 20kwh would still come closer to 3 miles each, than 2 (333Wh/mi vs. 500Wh/mi). No? That's where I came up with adding ~40-50 miles minimum. When you figure the i3 gets rated for ~87, on ~22kwh, we're already building in almost half the efficiency. Unless I am missing something, I think this sounds conservative.

I AGREE... adding a few hundred pounds, BUT a 25% bigger battery would mean 40 miles better range, not Slightly better. The weight, especially "at speed" wouldn't negate the far bigger battery. And yes, they can figure out a way to make it work. They certainly are not waiting for the giga factory to be up and running to offer a bigger battery.

 

[wk057]

I guess we have differing opinions on how much additional range is significant.

Honestly, ~250 miles is sufficient for 99% of use cases. Adding 40 more miles isn't going to change that. Adding 40 miles wouldn't even change the supercharger stops I needed on my frequent ~600 mile trip. Range would essentially need to be doubled to make any impact on the long trip's I've made so far, and the other 99% of the time I'd be lugging around a ton of underutilized capacity.

We're not talking about just adding a bit of weight and presto, more range. We're talking about redesigning the pack completely. They can't just throw four more modules in series with the existing 16 of the 85 pack to make a 105 pack. That would bump the pack voltage up near 500V! So, they'd have to configure it differently to work with the existing inverters/motors/chargers/DC-DC/etc, which work up to around 420VDC IIRC. There is no easy way to do this, not without adding complexity to production which Tesla has been adamant about reducing for efficiency gains.

To add 20kWh would be four more 85-style modules (444 cells each). Keeping the modules the same, let's say they split the 20 needed for a 105kWh pack in half to parallel half of them to keep the voltage lower. Well, then we're only working with nominal voltages that are 30% lower than the 60/70 packs, something like 220VDC. That's no good, motors wont move. And they can't do things asymmetrically because the pack won't charge/discharge evenly.

Let's say they redesigned the modules themselves to fix this voltage issue by doing 5 groups of ~88 cells in parallel per module instead of 6 of 74, then put 20 modules in series so we kept the voltage reasonable while adding capacity. Well, that's a complete module redesign, a complete BMS/BMB redesign, a redesign of the module's bus plates/fusing (higher current per group/module due to lower voltage per module), etc. Then, on top of that we now have 20 modules/~8900 cells instead of 16 modules/~7100 cells to cool. There goes a redesign of the cooling loop, fire arrest/protection setup, cell venting ducts/valve placement, etc. Can the existing components outside of the pack handle the cooling needs fo 4 additional modules? Need to verify that capability, possibly redesign, etc. Plus many more details to be addressed.

This is all non-trivial stuff, guys, for very little real gain. It would make *far* more sense to stick with the existing design, tweak it slightly when a better cell is utilized, and make a slightly higher capacity pack that way instead of doing a complete redesign for a small gain... something I really don't see happening in quantity until the gigafactory is online, among other reasons.

 

[sandpiper]

I guess we have differing opinions on how much additional range is significant.

Honestly, ~250 miles is sufficient for 99% of use cases. Adding 40 more miles isn't going to change that. Adding 40 miles wouldn't even change the supercharger stops I needed on my frequent ~600 mile trip. Range would essentially need to be doubled to make any impact on the long trip's I've made so far, and the other 99% of the time I'd be lugging around a ton of underutilized capacity.

We're not talking about just adding a bit of weight and presto, more range. We're talking about redesigning the pack completely. They can't just throw four more modules in series with the existing 16 of the 85 pack to make a 105 pack. That would bump the pack voltage up near 500V! So, they'd have to configure it differently to work with the existing inverters/motors/chargers/DC-DC/etc, which work up to around 420VDC IIRC. There is no easy way to do this, not without adding complexity to production which Tesla has been adamant about reducing for efficiency gains.

To add 20kWh would be four more 85-style modules (444 cells each). Keeping the modules the same, let's say they split the 20 needed for a 105kWh pack in half to parallel half of them to keep the voltage lower. Well, then we're only working with nominal voltages that are 30% lower than the 60/70 packs, something like 220VDC. That's no good, motors wont move. And they can't do things asymmetrically because the pack won't charge/discharge evenly.

Let's say they redesigned the modules themselves to fix this voltage issue by doing 5 groups of ~88 cells in parallel per module instead of 6 of 74, then put 20 modules in series so we kept the voltage reasonable while adding capacity. Well, that's a complete module redesign, a complete BMS/BMB redesign, a redesign of the module's bus plates/fusing (higher current per group/module due to lower voltage per module), etc. Then, on top of that we now have 20 modules/~8900 cells instead of 16 modules/~7100 cells to cool. There goes a redesign of the cooling loop, fire arrest/protection setup, cell venting ducts/valve placement, etc. Can the existing components outside of the pack handle the cooling needs fo 4 additional modules? Need to verify that capability, possibly redesign, etc. Plus many more details to be addressed.

This is all non-trivial stuff, guys, for very little real gain. It would make *far* more sense to stick with the existing design, tweak it slightly when a better cell is utilized, and make a slightly higher capacity pack that way instead of doing a complete redesign for a small gain... something I really don't see happening in quantity until the gigafactory is online, among other reasons.

With all respect, the gain may be trivial to many but certainly not to me or to the other owners in this area. In the winter, the run to my closest supercharger simply isn't doable, even with range mode on, 10-15 kmh under the limit, freezing feet and defrost on and off as required to keep a frost free hole so that I can see the road. That supercharger gets me access to pretty much everywhere I regularly travel to. If I could get a real 250 miles that would be different but in the winters up here it's simply not so, or even close.

Adding 20% would make a BIG difference. It would also allow for faster supercharging in cases when you don't need the full range. I hate having to charge to 100% but often enough there really is no option.

Adding 20% may well be technically non-trivial and it may not happen until the GF opens. But that doesn't negate the need.

 

[blackscraper]

With all respect, the gain may be trivial to many but certainly not to me or to the other owners in this area. In the winter, the run to my closest supercharger simply isn't doable, even with range mode on, 10-15 kmh under the limit, freezing feet and defrost on and off as required to keep a frost free hole so that I can see the road. That supercharger gets me access to pretty much everywhere I regularly travel to. If I could get a real 250 miles that would be different but in the winters up here it's simply not so, or even close.

Adding 20% would make a BIG difference. It would also allow for faster supercharging in cases when you don't need the full range. I hate having to charge to 100% but often enough there really is no option.

Adding 20% may well be technically non-trivial and it may not happen until the GF opens. But that doesn't negate the need.

I will second Sandpiper on this. 250miles is under quite good road conditions, it could be slashed to under 180miles under freezing winter thus making Model S an expensive but impractical toy which was designed to be a daily commuting car.

 

[No2DinosaurFuel]

Most likely they will not change the configuration of the packs. I suspect they will swap out the cells to get thr capacity gain. This is the path of least risk to the new pack in terms of engineering, testing, etc.

Still my take is thr 70KWh pack might stay, but the 85KWh has seen its days. We will see all the 85Kwh packs retired by the release of the model x or shortly after. The replacement will have higher capacity Whatever the capacity that will be. By then the 85D will see a proce cut for the inventory vehicles. Hopefully this is when i jump i. To snag a low priced inventory 85D.

 

[wk057]

With all respect, the gain may be trivial to many but certainly not to me or to the other owners in this area. In the winter, the run to my closest supercharger simply isn't doable, even with range mode on, 10-15 kmh under the limit, freezing feet and defrost on and off as required to keep a frost free hole so that I can see the road. That supercharger gets me access to pretty much everywhere I regularly travel to. If I could get a real 250 miles that would be different but in the winters up here it's simply not so, or even close.

Adding 20% would make a BIG difference. It would also allow for faster supercharging in cases when you don't need the full range. I hate having to charge to 100% but often enough there really is no option.

Adding 20% may well be technically non-trivial and it may not happen until the GF opens. But that doesn't negate the need.

I will second Sandpiper on this. 250miles is under quite good road conditions, it could be slashed to under 180miles under freezing winter thus making Model S an expensive but impractical toy which was designed to be a daily commuting car.

We'll agree to disagree I suppose. On my very first long trip with the Model S I drove in an ice storm between two superchargers at ~210 miles apart. Temperatures in the 20s with wind, ice, and snow. Left with nearly a full charge and I arrived at the destination supercharger with ~12 miles remaining. The supercharger handle was literally frozen to the pedestal and required some finesse to remove and clean the ice from it. The car still supercharged at near normal rates, too, since the pack was already warmer from the drive. Suffice it to say, I was more than impressed with the car at this point from multiple view points including cold weather range, handling, etc.

Keep in mind that pack size isn't the only limitation when supercharging. The supercharger could not safely output 120kW continuously, even if the pack could handle it, without upping wire sizes. Tesla is already beyond what I personally would consider a safe wire size for the power they're pushing, but the taper allows it because by the time the wiring heats up due to high amperage/resistance the power level is already dropping. They might be able to squeeze a bit more out of that from a technical standpoint... until someone burns their hand on a supercharger connector that's super hot from high current. They already are very hot in the peak power points of a charge, with the connector reaching 129F in my FLIR shots last summer on a ~75F night after only 20 minutes at less than peak power.

From a technical point of view, redesigning the pack to add 20% capacity with existing cells would just be silly when very soon (I'd guess within ~24 months) they'll just be able to reuse that design with better cells.

 

[blackscraper]

We'll agree to disagree I suppose. On my very first long trip with the Model S I drove in an ice storm between two superchargers at ~210 miles apart. Temperatures in the 20s with wind, ice, and snow. Left with nearly a full charge and I arrived at the destination supercharger with ~12 miles remaining. The supercharger handle was literally frozen to the pedestal and required some finesse to remove and clean the ice from it. The car still supercharged at near normal rates, too, since the pack was already warmer from the drive. Suffice it to say, I was more than impressed with the car at this point from multiple view points including cold weather range, handling, etc.

Keep in mind that pack size isn't the only limitation when supercharging. The supercharger could not safely output 120kW continuously, even if the pack could handle it, without upping wire sizes. Tesla is already beyond what I personally would consider a safe wire size for the power they're pushing, but the taper allows it because by the time the wiring heats up due to high amperage/resistance the power level is already dropping. They might be able to squeeze a bit more out of that from a technical standpoint... until someone burns their hand on a supercharger connector that's super hot from high current. They already are very hot in the peak power points of a charge, with the connector reaching 129F in my FLIR shots last summer on a ~75F night after only 20 minutes at less than peak power.

From a technical point of view, redesigning the pack to add 20% capacity with existing cells would just be silly when very soon (I'd guess within ~24 months) they'll just be able to reuse that design with better cells.

Well, let's try out in -20C weather which has been common during Jan and Feb 2015. most of Model S owners in southern Ontario whom I know reported less than 60% of the rated range while traveling on highway 401 during that time. headwind, awful road condition, freezing temperature, 110km/hr made a trip from Toronto Supercharger to Kingston supercharger quite a stretch for 85KWH owners. This has been quite common during the past Jan and Feb. I can understand Sandpiper's frustration on winter range as other owners told me the horrible range during freezing winter made Model S almost impractical for a short inter-city trip.

 

[sandpiper]

Well, let's try out in -20C weather which has been common during Jan and Feb 2015. most of Model S owners in southern Ontario whom I know reported less than 60% of the rated range while traveling on highway 401 during that time. headwind, awful road condition, freezing temperature, 110km/hr made a trip from Toronto Supercharger to Kingston supercharger quite a stretch for 85KWH owners. This has been quite common during the past Jan and Feb. I can understand Sandpiper's frustration on winter range as other owners told me the horrible range during freezing winter made Model S almost impractical for a short inter-city trip.

Bingo. My closest SC is 300km away. In February this year at -25C, there was zero chance even travelling at 80-90 km/hr. At warmer temps of 20+ degrees F it may have been very possible. Supercharging speed has never been an issue. And pushing more than 300 amps through that cable would be a bad idea.

 

[David99]

I think wk057 makes a very valid point. There is a lot of changes necessary to get 20% more capacity that would not be worthwhile. The current battery pack size simply doesn't have the space to fit in more cells. The only practical solution would be to use higher capacity cells.
There are always cases where the 20% difference is just at the tipping point for a certain person that makes or breaks it. But if we have 20% more, there are just as many Model S owners that are just too far to reach their Supercharger or desired destination. My point is, there will always be cases where, no matter what capacity, for whom it just isn't enough.

There is a reason why Tesla went with 85 kW. It more than covers the daily needs of the vast majority of drivers and it allows long distance traveling at a decent drive/charge ratio. Elon was asked about a higher capacity batter/car and he said they can make a car that goes 1000 miles but it would be a car that no one buys. It would be too expensive, too heavy and impractical as you drive around a huge amount of battery that you don't need in the majority of your driving. It would be a burden.

Maybe they will have a slightly higher capacity pack for the Model X that is based on better cells. A redesign of the battery pack will definitely be necessary once they switch to the slightly larger cells coming from the Giga factory. But that's still sime time in the future

 

[blackscraper]

@David99, IMHO, Tesla engineers have a mindset of "California" where it is quite populous, close to everything, and where there is mild weather. No wonder why Bjorn advocated 110KWH pack in his video although he is quite a Tesla fan, proud owner and lives in populous Europe but has a comparatively harsh winter and unlimited speed autobahn