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Roadster 3.0

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DrComputer

TeslaClubLA President
Jan 29, 2009
1,222
725
Sherman Oaks, CA
Here's an e-mail from Tesla that I just received:

Roadster 3.0
Battery technology has continued a steady improvement in recent years, as has our experience in optimizing total vehicle efficiency. We have long been excited to apply our learning back to our first vehicle, and are thrilled to do just that with the prototype Roadster 3.0 package. It consists of three main improvement areas.

Batteries
The original Roadster battery was the very first lithium ion battery put into production in any vehicle. It was state of the art in 2008, but cell technology has improved substantially since then. We have identified a new cell that has 31% more energy than the original Roadster cell. Using this new cell we have created a battery pack that delivers roughly 70kWh in the same package as the original battery.

Aerodynamics
The original Roadster had a drag coefficient (Cd) of 0.36. Using modern computational methods we expect to make a 15% improvement, dropping the total Cd down to 0.31 with a retrofit aero kit.

Rolling Resistance
The original Roadster tires have a rolling resistance coefficient (Crr) of 11.0 kg/ton. New tires that we will use on the Roadster 3.0 have a Crr of roughly 8.9 kg/ton, about a 20% improvement. We are also making improvements in the wheel bearings and residual brake drag that further reduce overall rolling resistance of the car.

Summary
Combining all of these improvements we can achieve a predicted 40-50% improvement on range between the original Roadster and Roadster 3.0. There is a set of speeds and driving conditions where we can confidently drive the Roadster 3.0 over 400 miles. We will be demonstrating this in the real world during a non-stop drive from San Francisco to Los Angeles in the early weeks of 2015.

We are confident that this will not be the last update the Roadster will receive in the many years to come.

Happy Holidays.
 
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Disappointing. 50% improvement is 366 miles under the old EPA test. Getting to 400 miles is going to require serious granny driving.

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Okay, so 31% more energy means 3.2 Ah cells.

That's the link to the cells I just posted...

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Woah - that's awesome, but not what we expected at all! They're not using a Model S cell, but one with a lot LESS capacity. I wonder if the S cells would have been too heavy?

No it's the same as the latest Model S. The older Model S pack was 3.1 Ah.

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They forgot the all important £ $ €.
 
First, wow that they are doing an aero and tire upgrade as well. Second, even with that, 380 ish miles from 70kWh = 184 wh/mi, which is pretty amazing, depending on what speed they are assuming. For those familiar with the route what is a reasonable average speed for that trip?

Oh, I just saw this part:

There is a set of speeds and driving conditions where we can confidently drive the Roadster 3.0 over 400 miles.

Well you can do the same with Roadster 2.0 at 18 mph too...
 
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Looks like the cells are going to be Samsung INR18650-29E. 3.6V 2.85AH, 1C continuous, 3C discontinuous. The cells being used in the Model S require a higher degree of thermal management than the cells currently used in the Roadster so are unlikely to be suitable for the Roadster. The Samsung 29E is well suited for less thermal management situations like in the Roadster.
 
Looks like the cells are going to be Samsung INR18650-29E. 3.6V 2.85AH, 1C continuous, 3C discontinuous. The cells being used in the Model S require a higher degree of thermal management than the cells currently used in the Roadster so are unlikely to be suitable for the Roadster. The Samsung 29E is well suited for less thermal management situations like in the Roadster.

Not sure why you think they'd us a Samsung cell when they can get better cells from Panasonic, plus the fact that the cell you specify doesn't meet the posted specs from Tesla.