I am just speculating about the battery size of the Model 3. I would appreciate any input.
So I have a few assumptions and then some math.
Tesla Model S seems to average about 3.6 mi/kwh
So if the Model 3 increased that by 10% (due to smaller size and weight - assumption) that would be about 3.96 mi/kwh.
Since they indicated during the unveiling that the model 3 would be around a 215 mile range that would mean a 50 to 60 kwh battery.
Any thoughts?
Where did you get the 3,6 miles per kWh figure for the Model S? That does not seem realistic to me.
Assuming the Model S 90D with 270 miles EPA range has about 81 kWh
usable battery capacity, the EPA rated energy consumption would be around 3.3 miles per kWh.
Of course the Model 3 is going to be more efficient, but there is no way the Model 3 is much more than 20% more efficient than the Model S. The EPA rated energy consumption should thus be 3.8 to 4 miles per kWh.
So the
usable battery capacity of the Model 3 would have to be about 54 to 57 kWh to reach 215 miles.
Thus, I think we will likely see a 60 kWh (54 kWh usable) or 65 kWh (58.5 kWh usable) battery pack.
Additionally, I estimate there will be a Model 3 with a 80-85 kWh battery pack with 72 - 76.5 kWh available, resulting in 270 to 290 miles of EPA rated range.
I think a 50 kWh pack is impossible and a 55 kWh pack very unlikely.
I am sure I have seen this elsewhere, but simple logic can be applied. Just looking at geometry, you could assume the loss of 4 out of the 16 battery modules. That is if nothing else about cell/module size or density changed. That would give you 12/16 the space for model 3 batteries. Scaling from the 70kWh and 90kWh you get 52.5kWh and 67.5kWh. So my vote, with no energy density improvement, is 50kWh and 70kWh for the two Model 3 battery variants.
Why should there be no energy density improvement?
I don't think it is unrealistic to expect a Model S with 80 and 100 kWh batteries by 2017.
There was already a leak about the P100D.
And by the way, the cell/module size changed too, at least according to the video Elon showed at the presentation of the Model 3.
Furthermore, the Model 3 seems to have a very long wheel base for its size – potentially making a pretty large battery possible.