Why do diff battery packs have diff 0-60mph times?

[TEG]

Reducing the number of cells and reducing the weight would help the 0-60 a lot.
4554 of the best Model S cells would produce about the same power and shave off 300ish pounds.
That could cut the 0-60 by 3 or 4 tenths. Done right it could also lower the CG which would be great for handling.

Hmm, redo the ESS insides so that it is 4554 cells on the bottom, and a liquid cooled PEM above. (You already have liquid cooling for the battery box.) Now you have the empty space above (where the old PEM went) to use as a storage area for the soft top and UMC, so you still have your full trunk even when "topless". Just an idea.

 

[stopcrazypp]

Check out the difference in packs between the Roadster and Roadster Sport

I thought you were discussing this in the context of the different battery sizes for the Model S (what Andrew was talking about and this thread was talking about).

The difference/bottleneck in the Roadster and Roadster Sport is in the motor (hand-wound for denser windings), not the battery. The difference/bottleneck in the Performance Model S is in the inverter. But in the case of the smaller packs in the Model S, the batteries are the bottleneck (I have heard all the Model S will use the same motor).

If #3 was the main reason, there should be evidence of throttling of performance (as in a software limit on performance, not hardware). I have seen no evidence of this so far.

 

[smoothoperator]

Hmm, redo the ESS insides so that it is 4554 cells on the bottom, and a liquid cooled PEM above. (You already have liquid cooling for the battery box.) Now you have the empty space above (where the old PEM went) to use as a storage area for the soft top and UMC, so you still have your full trunk even when "topless". Just an idea.

$80k later!

I would take a battery swap of 79kwh instead and have a 350 mile range. I just need more range.

 

[smoothoperator]

I thought you were discussing this in the context of the different battery sizes for the Model S (what Andrew was talking about and this thread was talking about).

The difference/bottleneck in the Roadster and Roadster Sport is in the motor (hand-wound for denser windings), not the battery. The difference/bottleneck in the Performance Model S is in the inverter. But in the case of the smaller packs in the Model S, the batteries are the bottleneck (I have heard all the Model S will use the same motor).

If #3 was the main reason, there should be evidence of throttling of performance (as in a software limit on performance, not hardware). I have seen no evidence of this so far.

The point I was trying to make is that the bottleneck could be the motor not the pack (as it was in the roadster)....I have seen conflicting information with regards to this. I do not think it is fact just yet, that the bottleneck is the pack in the Model S.

 

[gocken2]

I wonder for the Model S if going from a 40 kWh to 85 kWh pack years from now will offer the performance bump (without supercharging access though) since the motor seems to be the same across all cars.

I asked this question to the Tesla rep on my test drive. He said that it will get the same performance as the 85 KWh pack when the battery is upgraded.

 

[TEG]

The difference/bottleneck in the Roadster and Roadster Sport is in the motor (hand-wound for denser windings), not the battery...

This has been debated and discussed before, and I don't think we ever got consensus.
Aside from the possible motor winding differences, we heard there might be more IGBTs in the PEM, or maybe just different firmware. No official/final word on what exactly was done other than more amps at low RPMS.

 

[Vger]

Hmm, redo the ESS insides so that it is 4554 cells on the bottom, and a liquid cooled PEM above. (You already have liquid cooling for the battery box.) Now you have the empty space above (where the old PEM went) to use as a storage area for the soft top and UMC, so you still have your full trunk even when "topless". Just an idea.

A really good idea! Joost, are you listening!?

 

[jkirkebo]

Small typo by him there btw; the perf motor's rated at 310 kW, not 301.

Model S Options and Pricing | Tesla Motors (see the "Battery and Performance" matrix)

What IS the correct conversion factor to use between hp and kW ?

Tesla: 416hp/310kW=1,34
Leaf: 109hp/80kW=1,36

 

[ddruz]

What IS the correct conversion factor to use between hp and kW ?

Tesla: 416hp/310kW=1,34
Leaf: 109hp/80kW=1,36

According to eHow.com: "Both horsepower (hp) and kilowatts (kw) are units of power. As such, converting between the two is a straightforward calculation. The term horsepower was coined by the Scottish engineer James Watt to market steam engines in a power rating familiar to most people of the time. One horsepower is equivalent to 746 watts, or 0.746 kilowatts. The term watt was named after James Watt."

 

[WarpedOne]

What IS the correct conversion factor to use between hp and kW ?
Tesla: 416hp/310kW=1,34
Leaf: 109hp/80kW=1,36

From Wikipedia: Horsepower

Mechanical horsepower: hp(I) ≡ 33,000 ft-lbf/min = 550 ft·lbf/s = 745.699872 W
Metric horsepower: hp(M) ≡ 75 kgf·m/s ≡ 735.49875 W
Electrical horsepower: hp(E) ≡ 746 W
Boiler horsepower: hp(S) ≡ 33,475 BTU/h = 9,809.5 W
Hydraulic horsepower:
= flow rate (US gal/min) × pressure (psi) × 7/12,000
or
= flow rate (US gal/min) × pressure (psi) / 1714 = 550 ft·lbf/s = 745.699872 W

Cleary, Nissan uses metric horsepower (735,5 W/HP or 1,36 HP/kW).
As we are talking about electric machines, the correct factor to use is 746 W/HP or 1,34 HP/kW).