Model 3 Battery size

[arnis]

Yes, both the Model S 75D and Model 3 75D will charge to 100% at the same time. The power rate they can take is identical.

Man a lot of speculation here with very little supporting evidence cited...

That's a good observation.

Model S 75kWh pack, AFAIK, has lower voltage (has less modules inside), as the pack was originally 85kWh (then 90, then 100).
Model 3 75kWh will have full house in the pack, therefore around 400V, Model 355 will be the stripped down version with lower voltage.
S75D and 375D will very likely not charge to 100% within the same time period. There are arguments in both directions:
Higher voltage on 3, therefore less amps required for the same kW rate compared to S.
Less cooling capability on 3, therefore slower in warm weather.
2170 might have better charge acceptance (voltage will hit the 4.2V mark per cell later than with 16850 cells), therefore tapering later.

 

[scaesare]

@scaesare
From Wikipedia:

Tesla Powerwall - Wikipedia

6.4 kWh -> 13.5kWh Over 100% increase
Weight however is 20+% higher at 119.9 kg compared to 97 kg.
What I clearly stated was 2x the kWh in a slightly larger and heavier package, so not 2x the energy density since the physical size and volumes are critical in automotive solutions.

Model Technology Price (US$)b Capacity (kWh) Wh per US$ US$ per kWh Power Operating temp. Weight Dimensions (H x W x D) Cycles (during Warranty) US$ per warranted kWh
Powerwall 1 lithium-ion US$3,000 6.4 2.13 469 7 kW peak / 5 kW continuous −4 to 110 °F (−20 to 43 °C) 214 lb (97 kg) 51.3 in × 34 in × 7.2 in (130 cm × 86 cm × 18 cm) 5,000 [9][10]
Powerwall 2 lithium-ion US$5,500a 13.5 2.46a 407a 7 kW peak / 5 kW continuous −4 to 122 °F (−20 to 50 °C) 264.4 lb (119.9 kg) 44 in × 29 in × 5.5 in (112 cm × 74 cm × 14 cm) - ~0.17[18]

Powerpack2 is exactly 2x the capacity at the same dimensions and weight.

I realize that powerwalls and powerpacks are not the same as the automotive packs, but this clearly shows what kinds of improvements they have made going from 18165 to 2170. I am sure that many of the improvements apply to both storage as automotive.

Added link to more detailed specs of PW2:
Powerwall 2 Full Specs Reveal Cheap Storage And Limited Warranty

I'm honestly not sure what this is responding to.

Are you using this as evidence that JB's "30%" improvement # is wrong?
That Elon's "100kw wont fit in model 3" is wrong?

Something else?

 

[JRP3]

2170 might have better charge acceptance (voltage will hit the 4.2V mark per cell later than with 16850 cells), therefore tapering later.

Per cell doesn't matter because the cells are physically larger, i.e. greater amp hour capacity. For example 2 3 amp hour cells in parallel don't charge at a different rate than a single 6 amp hour cell. In both cases the total amp hours are 6 so capacity is equal.

 

[arnis]

Nono, I actually think better charge acceptance per kWh. I was surprised that that Ioniq is able to charge at 70kW for
up to 75% SOC. And it only has 28kWh battery pack. Compared to Model S/X, that is way way better.
Therefore it is reasonable and possible to tweak acceptance, it should also mean less resistance, therefore less heat generation.
It's just my guess. No official information.
Acceptance rate is more important on smaller battery packs (to keep charging rate from going down, kW, not range).
Again, thermal throttling is another enemy and that I'm worried about much more.

 

[JRP3]

I was surprised that that Ioniq is able to charge at 70kW for
up to 75% SOC.

Different cell chemistry so irrelevant to the discussion.

 

[scaesare]

All these calculations on range only takes into account drag coefficients, weight and rolling resistance.

Does anyone have an idea about improvements in electronics, motor and energy conversion? Could it be a nice surprise?

I'm thinking about the hyundai ionic whose efficiency is remarkable and not only for its weight, rolling resistance and drag coefficient.

I'm only passingly familiar... what are those specific efficiencies you are referring to?

 

[CameronB]

I've seen several people say (almost definitively) that the new 2170 cells will not have a higher C (charge) rate than the current cells. But is that a fact? With Elon talking about future Supercharger V3 with > 350 kW power output...wouldn't it stand to reason that the cells would need to be able to accept a higher c rate? And if the new 2170 cells replace the former cells that have been used for many years, I'd think that the 2170 would be the new standard for years to come. Eventually would of course be superseded by something newer/better, but given the relatively slow evolution from one cell to another, I'd think that it would be smart to 'future proof' the 2170 enough to, if not accept the full power output of a >350kW V3 Supercharger, at least be able to accept a significantly higher c rate than the current cells.

I thought I had read that the 2170 would be 30% more power dense. If that's right than a 70kWh pack in a Model 3 could provide near equivalent to a 100kWh pack in a Model S using the now current (18650) cells. Would be less since the packs will be smaller than could be fit in the S, but 30% is still a huge increase.

With there potentially being 500,000 Model 3s on the road by the end of 2018 (it could happen! Or not! But let's be optimistic) even continued build out of the Supercharger network seems on the surface to be insufficient. But what if the range on the bigger/optional Model 3 batteries is significantly more because of the 30% higher energy density...and what if the Model 3 packs could charge significantly faster by accepting higher c rates of near-term improvements to the Superchargers being built today. Maybe in combination the hand wringing about having the SC network being overwhelmed by road tripping Model 3s in a year or two will turn out to be not nearly as big a deal as some think it might be. I could be completely wrong. Or mostly wrong. But I just have a feeling the new cell may be more transformative than some are assuming.

 

[arnis]

Different cell chemistry so irrelevant to the discussion.

So using different chemistry is an excuse to having worse charging capabilities?
I don't think so. If others make progress, Tesla must also catch up.
If others found a way to charge 100kWh pack at 245kW up to SOC75%, Tesla shall add that to the "to do" list.

 

[Model 3]

So using different chemistry is an excuse to having worse charging capabilities?

Everything is a compromise. Making a battery is a compromise between power (that how fast a battery may charge or discharge), weight, volume, price and long life...

 

[ModelNforNerd]

You've illustrated that total charge time spent is dependent on vehicle efficiency, which does not affect the speed (or rate) of charge, but rather the session duration necessary.

Excellent.

Yes, in a real world application, such as the wife and I driving from MA to VA to visit her family, I'm going to be concerned with the 90 min to 2 hours' worth of time I may have to spend at Superchargers, adding to the 10-ish hours of actual drive time.


Plot twist: unlike an ICE, my Tesla will be doing much of the driving in this scenario.

 

[JRP3]

I've seen several people say (almost definitively) that the new 2170 cells will not have a higher C (charge) rate than the current cells. But is that a fact?

Simply changing the container size will not increase C rate, in fact it could slightly lower it. So if 2170 cells end up with a higher C rate it will be from other changes independent of the cell size.

 

[JRP3]

So using different chemistry is an excuse to having worse charging capabilities?

In effect, yes. For example LiTi chemistry has very high C rates but poor energy density. A Model 3 with LiTi could charge in 5 minutes, but would only have about a 100 mile range, and probably cost at least twice as much. Tesla uses NCA because it has the best energy density, lowest cost, and acceptable C rates.

I don't think so. If others make progress, Tesla must also catch up.

See above. Others must catch up to Tesla's energy density and low cost.

If others found a way to charge 100kWh pack at 245kW up to SOC75%, Tesla shall add that to the "to do" list.

Only when they feel it's more important than energy density and low cost.

 

[Troy]

I've seen several people say (almost definitively) that the new 2170 cells will not have a higher C (charge) rate than the current cells. But is that a fact?

Hi, @CameronB. See my message HERE from last week. I do believe the 2170 cells will support higher kW rate than the 18650 cells because of different chemistry but for higher power rates Supercharger V3 hardware will be needed. Supercharger V1 output was 120 kW. Currently, V2 output is 135 kW. HERE is a photo. Now, Elon has started talking about Supercharger V3.

 

[scaesare]

In addition. you realize that there are other ways of managing the overall charge experience.

One way is to use a chemistry that allows faster C-rates. Another is to use a larger pack that with lower C-rates.

The key is understanding that the rate is a ratio of the pack size. So while it sounds like the Ioniq is way ahead when you say it's pack is capable of charging at 3C, whereas the Telsa is only about half that rate, the reality is the Tesla accepts more power, as a result of it's larger pack size. The Ioniq gains ~22kWh (80%) in 20 minutes. In that time a 100kWhTelsa will have gained something like 35-40kWh.

So as @JRP3 mentions, the tradeoff in other factors (energy density, cost), may force a smaller pack, which although has a greater C-rate, actually accumulates total energy at a slower pace. What's more, it also has to charge more often

It is indeed all about balance of factors..

 

[CameronB]

Hi, @CameronB. See my message HERE from last week. I do believe the 2170 cells will support higher kW rate than the 18650 cells because of different chemistry but for higher power rates Supercharger V3 hardware will be needed. Supercharger V1 output was 120 kW. Currently, V2 output is 135 kW. HERE is a photo. Now, Elon has started talking about Supercharger V3.

Good thread! Yeah I understand that we would require V3 Supercharger hardware and that's coming at some point. What I don't know is how much additional charge could the current cells in Model S handle even with 350kW+ hardware. And so my thinking is that Tesla would make the new cells able to accept greater input and result in a higher C rate. Because if they didn't...then they'd have all the Model S and Xs on the road not able to take advantage of the 350kW+ PLUS hundreds of thousands or millions of Model 3 *also* not able to take advantage of it...wouldn't make sense to me.

Because if none of your customers see much practical decrease in the time they spend at the Superchargers, having 350kW or even 500kW potential doesn't seem to provide much point, unless I am missing something. It's like Tesla building a massive firehose but nobody can drink from it (don't try this people!)

 

[ModelNforNerd]

Good thread! Yeah I understand that we would require V3 Supercharger hardware and that's coming at some point. What I don't know is how much additional charge could the current cells in Model S handle even with 350kW+ hardware. And so my thinking is that Tesla would make the new cells able to accept greater input and result in a higher C rate. Because if they didn't...then they'd have all the Model S and Xs on the road not able to take advantage of the 350kW+ PLUS hundreds of thousands or millions of Model 3 *also* not able to take advantage of it...wouldn't make sense to me.

Because if none of your customers see much practical decrease in the time they spend at the Superchargers, having 350kW or even 500kW potential doesn't seem to provide much point, unless I am missing something. It's like Tesla building a massive firehose but nobody can drink from it (don't try this people!)

that's just it.....the 2170-packed Model 3's may very well be able to drink from this "hose", as well as future S and X's (and the Y). The "legacy" (18650) vehicles would be throttled back based on their initial handshake with the Supercharger.

If the majority of Teslas on the road will be powered by 2170 packs in the next 3-5 years, shaving minutes off of each vehicle's charge time will be a significant time savings fleet-wide, something we'll all appreciate if we happen to get in line at a busy Supercharger.

 

[stopcrazypp]

Good thread! Yeah I understand that we would require V3 Supercharger hardware and that's coming at some point. What I don't know is how much additional charge could the current cells in Model S handle even with 350kW+ hardware. And so my thinking is that Tesla would make the new cells able to accept greater input and result in a higher C rate. Because if they didn't...then they'd have all the Model S and Xs on the road not able to take advantage of the 350kW+ PLUS hundreds of thousands or millions of Model 3 *also* not able to take advantage of it...wouldn't make sense to me.

Because if none of your customers see much practical decrease in the time they spend at the Superchargers, having 350kW or even 500kW potential doesn't seem to provide much point, unless I am missing something. It's like Tesla building a massive firehose but nobody can drink from it (don't try this people!)

Actually plenty can take advantage of the 350kW power. Currently superchargers max out at 145kW so when they are split, they can't provide the full 120kW to each car. With 350kW superchargers, they can split and still provide 120kW to each car.

 

[JoseBQ]

I'm only passingly familiar... what are those specific efficiencies you are referring to?

Hyundai ionic ev gets 10-20% more efficiency than any other ev, even those lighter and with lower rolling resistance as the bmw i3.

Hyundai Ioniq Electric becomes most efficient electric car ever rated by the EPA

As someone said, it's also remarquable the rate of charge similar to Teslas and bolts with much smaller battery.

 

[scaesare]

Cool thanks. If they aren't attributing it to weight or rolling resistance factors, that would seem to leave aero and electronics/drivetrain efficiency.

It looks reasonably aerodynamic. I wonder if there's anything particularly novel about the drivetrain...

 

[Topher]

I wonder if there's anything particularly novel about the drivetrain...

Not a lot of room there at the top for drive train improvements.

ETA: Looking at the others top performers, its highway mileage is about the same, the improvement is almost totally in city mileage, which would lean toward weight and regen braking for possible areas for the improvement.

Thank you kindly.