Model 3 Battery size

[CameronB]

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.

I get that. But, let's say it is 400kW (because Elon says 350kW is a child's toy)...

Split that and each car can get 200kW. Can the current batteries take FULL advantage of 200kW? It still seems to me that the new cells/batteries will take better advantage.

 

[stopcrazypp]

I get that. But, let's say it is 400kW (because Elon says 350kW is a child's toy)...

Split that and each car can get 200kW. Can the current batteries take FULL advantage of 200kW? It still seems to me that the new cells/batteries will take better advantage.

I don't know about "full advantage," but I do know the battery cells can definitely handle more than the 120kW max (per stall) that the superchargers can provide today. Right now the bottleneck appears to be the supercharger connector/conductors.

For example, the S60 (the older one, not the newer software locked one) can do 104kW. That is ~1.7C. So for the 100kWh pack that suggests 170kW is possible.
Tesla Model 3 vs Chevy Bolt

 

[arnis]

What I don't know is how much additional charge could the current cells in Model S handle even with 350kW+ hardware

Absolutely nothing. Whatever the SC output, 90kW, 120kW, 135kW, 350kW - plug/socket can transfer up to 335A which usually means around 120kW max.

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.

Charger output has no other purpose beside making things cheaper and dividing power better between vehicles.
It's possible that new SC charger will be 600kW and divide that to 12 stalls. Doesn't matter when you are there alone.

I get that. But, let's say it is 400kW (because Elon says 350kW is a child's toy)...

Doesn't matter. My suspicion is that it will be above 350kW (for example 400kW) and one charger will serve 8 stalls.

Right now the bottleneck appears to be the supercharger connector/conductors.

Actually the biggest problem is thermal stability. There is a heat buildup problem which doesn't allow full SC speed in some weather scenarios. Even if plugs and sockets could handle (very likely not possible any more) more amps thermal problem will go nowhere. The only way is to make charging more efficient (better chemistry). Adding cooling capacity is not possible (long story).

PS, cooling capacity is per vehicle. So smaller packs have still the same cooling capacity. Therefore higher C-rates possible. This is why Ioniq can charge at 70kW that small 28kWh pack. If Ioniq just triples the pack capacity
(for example they stick 2 more packs in the trunk) they will not be able to charge at 3x70=210kW rate (even if plug allows). I bet Ioniq will not even handle 140kW for long. Same with Model 3/S/X.

 

[stopcrazypp]

Charger output has no other purpose beside making things cheaper and dividing power better between vehicles.
It's possible that new SC charger will be 600kW and divide that to 12 stalls. Doesn't matter when you are there alone.

My comment is directed at whether there would be any potential practical advantage to having 350kW charger even though the connectors can only handle 120kW at the moment, and clearly there is in terms of splitting if they use the same layout as currently

Actually the biggest problem is thermal stability. There is a heat buildup problem which doesn't allow full SC speed in some weather scenarios. Even if plugs and sockets could handle (very likely not possible any more) more amps thermal problem will go nowhere. The only way is to make charging more efficient (better chemistry). Adding cooling capacity is not possible (long story).

PS, cooling capacity is per vehicle. So smaller packs have still the same cooling capacity. Therefore higher C-rates possible. This is why Ioniq can charge at 70kW that small 28kWh pack. If Ioniq just triples the pack capacity
(for example they stick 2 more packs in the trunk) they will not be able to charge at 3x70=210kW rate (even if plug allows). I bet Ioniq will not even handle 140kW for long. Same with Model 3/S/X.

I don't think the additional power will be provided by more current (which would touch on a thermal problem), but rather by more voltage. This becomes an insulation problem on the connectors and conductors (and the supercharger hardware must support higher voltage).

As for whether it is a global cooling problem at the cell/pack level, I don't believe the evidence points to that. Everything currently points to it being a current limit on the supercharger connectors.

Lithium ion charging reaction is a endothermic reaction (meaning it absorbs heat). So the largest contributor of heat at the cell level would be internal resistance, which also happens at discharge. Tesla's cooling system is able to handle the heat from 500kW of discharge. Of course when supercharging, the car is stationary, so fan speeds have to be factored in.

But doing some math, assuming 200kW charging, 8256 cells (24.2W per cell), cell impedance 40 milliohms. Peak charging power happens at approximately 320V pack voltage which is 3.33V cell voltage, so 7.27A charging to get 24.2W. Power loss is 7.27A^2 * 0.04 ohms * 8256 cells = 17.5 kW of heat.

 

[scaesare]

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.

I hadn't looked at the weight... so that makes sense if it's stop--n-go gains...

Thanks.

 

[scaesare]

Whatever the SC output, 90kW, 120kW, 135kW, 350kW - plug/socket can transfer up to 335A which usually means around 120kW max.

Actually the 70's have been shown to draw ~365A at the Superchargers. I do suspect that's getting at about the absolute limit, however.

 

[JoseBQ]

Is it possible to increase voltage to 800 V in order to increase power?

 

[alseTrick]

"All I know is it would be a bad look if the 3 offered the same battery as the Bolt but the Bolt had a larger range."

Not really.

Agree to disagree.

 

[Yggdrasill]

My expectation for charging is something like a 500 kW supercharger with four stalls, where each stall can recieve 250 kW.

I expect no increase in voltage (although I'm not ruling out an 800V solution, either), while liquid cooled cables and plugs allow for 250 kW at 400V/625A. The cabling in the cars also need to be beefed up substantially, as well as the battery pack cooling.

Looking at what's technically possible, it's relatively easy to cool transformer oil down to around 5C/41F and inject it directly into the supercharger plug housing, then it could be circulated through the cable conduit back to the reservoir. Maybe you could even cool it to below 0C, but I suspect the cable might become uncomfortable to handle, and the plastics could start to become rigid.

I really don't think cabling or cooling is an issue. The hard limitation is battery chemistry.

 

[stopcrazypp]

My expectation for charging is something like a 500 kW supercharger with four stalls, where each stall can recieve 250 kW.

I expect no increase in voltage (although I'm not ruling out an 800V solution, either), while liquid cooled cables and plugs allow for 250 kW at 400V/625A. The cabling in the cars also need to be beefed up substantially, as well as the battery pack cooling.

Looking at what's technically possible, it's relatively easy to cool transformer oil down to around 5C/41F and inject it directly into the supercharger plug housing, then it could be circulated through the cable conduit back to the reservoir. Maybe you could even cool it to below 0C, but I suspect the cable might become uncomfortable to handle, and the plastics could start to become rigid.

I really don't think cabling or cooling is an issue. The hard limitation is battery chemistry.

The reason why I say voltage is the most likely strategy is because that is what all the CCS backers are going to and Tesla just joined their group. So if Tesla has intentions to harmonize with their standard, high voltage is the way to go.

 

[LargeHamCollider]

Looks like the biggest battery will be 75kWh per Elon tweeted.

 

[geoffreak]

Looks like the biggest battery will be 75kWh per Elon tweeted.

And here's the source

@kryniog The shorter wheelbase only allows for a 75 kWh pack in Model 3 at current cell/module energy densities

 

[JRP3]

Looks like the biggest battery will be 75kWh per Elon tweeted.

Finally we can put an end to some of the ridiculous speculation.

 

[ItsNotAboutTheMoney]

Finally we can put an end to some of the ridiculous speculation.

Well, reading between the lines he obviously means that there's new tech coming that will increase the density.

 

[boaterva]

Looks like the biggest battery will be 75kWh per Elon tweeted.

So, can I/we assume that 'current density' does mean using 2170s, since that's what been stated all along the 3 is coming with?

 

[Yggdrasill]

About as expected, then.

Model 3 Battery size
2017 Investor Roundtable:General Discussion

 

[ItsNotAboutTheMoney]

Finally we can put an end to some of the ridiculous speculation.

OK, being more serious: hurrah!

Model S75 is 249 miles range. Can we now do some wild speculation on the 375 range?

If base is 3/4 of 75kWh then it'd be 56.25kWh. So Model 3 base 55?

 

[Rashomon]

My calculations (conservative) show highway range should be just over 300 miles with 75kWh, and that's at 75 mph, not EPA speeds. EPA overall average range should be around 300, plus or minus. Anyone willing to cruise at 55 or 60 is going to generate some fairly amazing numbers.

 

[LargeHamCollider]

About as expected, then.

Model 3 Battery size
2017 Investor Roundtable:General Discussion

Your last post here is from Feb. 4th. It looks like we came to identical conclusions separately wrt cell count/pack config. Here's a post I made Feb. 1st: Model 3 Battery size
If I recall we also independently and correctly called the configuration of the 100kWh packs.

Feeling pretty confident about pack size/range of M3.

Edit: This also provides a possible explanation for the discontinuance of the 60kWh MS. A 56kWh M3 will have more range than a 60kWh MS. I don't think Elon would want this.

 

[smak]

Why does the Model 3 potentially get 300 miles with the 75 battery, but the S only 250? Is it simply the weight difference? Or better battery, or both?

-smak-