View Single Post
Old 08-03-2009, 03:40 AM   #22 (permalink)
The Atomic Ass
Master EcoModder
The Atomic Ass's Avatar
Join Date: Oct 2008
Location: Mason, OH
Posts: 535

Priinocchio - '17 Toyota Prius Two Eco
90 day: 58.85 mpg (US)
Thanks: 11
Thanked 20 Times in 17 Posts
Originally Posted by RobertSmalls View Post
What if your batteries are full and you *need to stop*?

No, you'll want the braking system to be able to generate 1000 HP or so, and you'll want it to be operable even if driveshafts break, electrics fail, and you lose power from the motor(s).

And wait a minute, you're going to water cool four hub motors? Two flexible coolant lines to each wheel, a water pump, an unaerodynamic radiator, umpteen gallons of coolant at 8lbs/gal...

There are very sound engineering reasons why most of the electrics on the road are tiny, low-performance machines. Start small.
The motors generate electricity, so even if the batteries fail, you still have electricity. I anticipate a failsafe which electrically jams all 4 motors. It wouldn't be a desirable stop, but it would stop pretty quick.

You can move just as much heat by moving half the coolant at twice the speed, and the radiator does not need to be either huge or constantly exposed.
  Reply With Quote