Poll on battery size.

[Todd Burch]

Smorgasbord, good point...I guess saying it's significantly conservative would be a stretch. We don't have width/height info, although I'd be surprised if frontal area for the Model S is more than about 15% larger than the Roadster...so there should still be probably 5-10% savings. But just a guess.

 

[smorgasbord]

From TeslaMotors.com:

Model S has approximately the following dimensions:

Overall length 16’4" (4973 mm)
Overall height 4’8" (1426 mm)
Overall width with mirrors 7’2" (2189 mm)
Ground Clearance 4.46" (113 mm)

How much should we subtract off for the mirrors? What is the frontal surface area of the Roadster?

 

[Todd Burch]

Here's what I found:

Roadster:
Width: 72.9" without mirrors
Height: 44.4"
Ground clearance: 5.1"

Model S:
Width with mirrors: 86"
Mirror width (estimate): 8" each side
Height: 56"
Ground Clearance: 4.5"

Roadster area: 72.9" x (44.4" - 5.1") = 2865 in^2.
Model S area: (86" - 2 x 8") x (56" - 4.5") = 3605 in^2.

So the Model S is about 25% larger in frontal area, 23% smaller in Cd.

So I stand corrected...they're probably pretty similar, although I've heard rumors of the Model S Cd being .25, which would make its Cd 29% smaller than the Roadster.

Does anyone know if aerodynamic effects such as ground clearance are considered in the vehicle's Cd? I assume it is, but you never know. I think smaller ground clearance results in less drag. (NASCAR fans, correct me if I'm wrong...)

 

[donauker]

Roadster area: 72.9" x (44.4" - 5.1") = 2865 in^2.
Model S area: (86" - 2 x 8") x (56" - 4.5") = 3605 in^2.

So according to your calculations the Model S width will be 3 inches narrower then the Roadster?! Good luck with that three adult rear seat!

 

[Todd Burch]

So according to your calculations the Model S width will be 3 inches narrower then the Roadster?! Good luck with that three adult rear seat!

I have two four-door sedans by different manufacturers. The width of the side mirrors on both of them are approximately 9", so 8" is not a crazy estimate.

I'm going off of published widths of the Roadster (without mirrors), along with the published width of the Model S (with mirrors). If you consider that the car tapers out perhaps a few inches from the mirrors, then maybe subtracting 8" is a bit more than necessary, but if you can find more accurate numbers, please enlighten us.

 

[aviators99]

I would have gotten the 160, because I think that's all I need and because of swapability. However, because of the changes in the way things are being assembled, I guess I won't have a choice, and will have to get the 300. (I am R140).

 

[William13]

The most important thing is the velocity is squared. Going at 60 mph has half the drag of going 85 mph. The main use of electricity is going against the drag. You can't go as far if you are speeding along.

 

[Eberhard]

What is really as important as the size of the batterie, is the speed of the onboard charger. 150mile range with 22kw charger brings you quicker further on a long distance ride then a 3.5 kW charger (16A) with a 300mile pack

 

[Doug_G]

What is really as important as the size of the batterie, is the speed of the onboard charger. 150mile range with 22kw charger brings you quicker further on a long distance ride then a 3.5 kW charger (16A) with a 300mile pack

Assuming there are any charge points whatsoever in existence, which is not the case here.

 

[neroden]

Assuming there are any charge points whatsoever in existence, which is not the case here.

Exactly. The closest thing to a charge point in much of North America is an RV park with 240 V 50 amp service. Consider that the maximum, and notice how far apart they are.

 

[Eberhard]

everywhere in Europe, you can find 32A 3-phase sockets, offering 3x32A = 96A = 22kW

 

[jkirkebo]

everywhere in Europe, you can find 32A 3-phase sockets, offering 3x32A = 96A = 22kW

Not everywhere. Most of Norway is only 230V 3-phase, not 400V. Thus 3x32=55A, 55A*230V=only 12.6kW. 22kW is still way too low to be usable on a road trip, I'd consider 44kW (3x63A) the bare minimum with a preference for 62.5kW CHAdeMO (probably around 60kW for the Model S, depending on battery voltage (I suspect around 480V)).

 

[Eberhard]

Not everywhere. Most of Norway is only 230V 3-phase, not 400V. Thus 3x32=55A, 55A*230V=only 12.6kW. 22kW is still way too low to be usable on a road trip, I'd consider 44kW (3x63A) the bare minimum with a preference for 62.5kW CHAdeMO (probably around 60kW for the Model S, depending on battery voltage (I suspect around 480V)).

3-phase 32A is 230V phase to neural. 400V is phase to phase. the charging is always done at 230V phase to neutral. If you have 230V phase to phase you have to calculate 32A * root of 3 = 55A

 

[jkirkebo]

3-phase 32A is 230V phase to neural. 400V is phase to phase. the charging is always done at 230V phase to neutral. If you have 230V phase to phase you have to calculate 32A * root of 3 = 55A

Norwegian 3-phase is 230V phase to phase and 130V phase to ground (never used).

 

[gg_got_a_tesla]

160 miles given my daily 55-mile-roundtrip commute (mixed city/hwy). Good enough for those sporadic 100-mile weekend trips as well. Will fall back to my wife's Mini Clubman (or a Hertz rental) for looonger trips!

Hmm.... having second thoughts about this. Given all the input I've seen about the 160 miles really being the very-ideal range (with new batteries, no lead-foot driving, no "showing-off" acceleration, warm enough weather, no hilly terrain etc. etc.), I wonder if those 100-mile weekend trips will be possible in just 2-3 years after I get the car (if the range drops to 80 miles at that point with all those factors in there).

It doesn't make sense if I cannot take this people-and-stuff mover for say, Newark, CA -> Santa Cruz, CA and back without having to recharge in Santa Cruz. In general, I'm quite wary of leaving the charging cable out there for vandals to target (just because they can) even if I can find a charging station to begin with - I can't babysit it through the charging period, of course.

Gosh, got to push my budget to get the 230-miler if not the 300 one while hoping that the current low auto loan interest rates last for another year or so :frown: On to weaving a story to convince the wife :tongue:

 

[Mycroft]

And there are the option$ as well. You're right, this 1.1% auto loan deal can't last forever.

 

[dsm363]

Hmm.... having second thoughts about this. Given all the input I've seen about the 160 miles really being the very-ideal range (with new batteries, no lead-foot driving, no "showing-off" acceleration, warm enough weather, no hilly terrain etc. etc.), I wonder if those 100-mile weekend trips will be possible in just 2-3 years after I get the car (if the range drops to 80 miles at that point with all those factors in there).

It doesn't make sense if I cannot take this people-and-stuff mover for say, Newark, CA -> Santa Cruz, CA and back without having to recharge in Santa Cruz. In general, I'm quite wary of leaving the charging cable out there for vandals to target (just because they can) even if I can find a charging station to begin with - I can't babysit it through the charging period, of course.

Gosh, got to push my budget to get the 230-miler if not the 300 one while hoping that the current low auto loan interest rates last for another year or so :frown: On to weaving a story to convince the wife :tongue:

A 230 mile pack should be more than enough for the occasional 100 mile trip, even after a few years. Just an estimate, but charing in standard mode and driving at normal highway speeds with air conditioning...etc, you should have around 150 miles of range (at least with the Roadster as a guide). Of course if you charge in range mode for your trip, you'll get more.

 

[joefee]

160

I'm betting range and price will improve significantly in 5 yrs when you may need a new pack. Also, I may do a lease if terms are good.

 

[robaross]

How can you decide on pack size when you don't know how it will affect performance. If the 160 is like a V6, the 230 like a V8, and the 300 like a V12, you've got to go with the 300. If performance is not affected by the pack size then a smaller range may suffice. I know I was thinking small since my commute is 65 miles round trip and that's the longest trip I would take except on a very rare occasion when I'd use the wife's ICE. Now I may rethink it and go bigger if that means extra oomph.

 

[qwk]

How can you decide on pack size when you don't know how it will affect performance. If the 160 is like a V6, the 230 like a V8, and the 300 like a V12, you've got to go with the 300. If performance is not affected by the pack size then a smaller range may suffice. I know I was thinking small since my commute is 65 miles round trip and that's the longest trip I would take except on a very rare occasion when I'd use the wife's ICE. Now I may rethink it and go bigger if that means extra oomph.

Exactly....