Why would battery capacity affect performance in Tesla Model S?

[SoCalGuy]

Not sure how the various battery options can affect the 0-60 times in the Model S. They're offering 40kwh, 60 and 85kwh options. Isn't the only difference in these batteries size/capacity? I would think the power output is the same, as would be the electric motors in each car. What am I missing?

[Fabulist]

(02-02-2012 09:12 AM)SoCalGuy Wrote:  Not sure how the various battery options can affect the 0-60 times in the Model S. They're offering 40kwh, 60 and 85kwh options. Isn't the only difference in these batteries size/capacity? I would think the power output is the same, as would be the electric motors in each car. What am I missing?

You can also get the regular or "performance" version of the same battery size, so they must have a way to set upper limits for the current draw to trade off range for performance or vice versa. The connections must be specified for the maximum amperage and the computer limits how much can be drawn, similar to electronically limiting an engine's RPM.

-- Fab.

[AnOutsider]

There's a large discussion on that over at TMC, but for the most part, it's being able to draw power at higher rates in a short time that does it. IIRC, the performance version likely has a different inverter to get more power through to the motors.

Disclaimer: this is just what I gleamed from past discussions. I'm no engineer.

[kabalah70]

AnOutside, I would agree, the battery will be the same, it is the drivetrain electronics, i.e. inverter/motor that will be different.