Well I'll be dang. I saw that battery symbol, but didn't notice that it was also a charge indicator. Just got back from my son's school open house (4 blocks away). Wow is my battery low tonight. Probably won't get much for mileage tomorrow as the short trips we'll make will be spent charging the battery.

Mark

 

I believe...and someone correct me if I am wrong....but I believe the motor is the limitation for speed not the battery. The system is limited to 41 MPH or so to protect the motor. Also, there is a system limitation in terms of wattage that the motor can draw before the engine kicks in.

Battery improvements will affect range, but speed is limited by the motors.

 

YES!

 

A larger motor is not the issue. A larger, more powerful battery would be a huge improvement. However, energy is energy, and you have to buy it somewhere.
Either the electric power company if you plug your hybrid battery in at night, or via the gasoline needed to recharge it. ( or you have to buy solar panels )

Right now, in most parts of the world, electricity costs about $2 for the equivalent battery charge as a gallon of gas. Just one reason why electric cars were not popular untill recently. Gas used to be cheaper! *Not anymore!

As-is the FEH will go 0-40 MPH on the electric motor alone. Adequate for 90% of city driving if the battery lasted longer.

 

There is also a definite limit of how much current you can pull from the battery at one time before the voltage drops too much. How do I know? When the car is in reverse it is only propelled by the elelctric motor. At a certain point when backing up a hill, you exceed the current draw limits on the battery and the engine kicks on to turn the generator to provide more current to the motor. There is no reverse gear. You'll also see this sometimes in forward when the ICE will kick on and the generator arrow will come on in the NAV display... but there will be no arrow going from the engine to the wheels. Just an arrow from ICE to the motor, one from the motor to the wheels, and one from the battery to the motor. At that point the motor is driving the car, but current is coming from the battery and the generator powered by the motor.

At slow speeds where more torque is required this can be more efficient than reving the ICE up really fast and using a large step down gear in a transmission.

As I understand things.... I'm an EE not an ME or a mechanic.

 

So...if going in reverse is all motor powered, then if I put the MMH/FEH in reverse, start accelerating, I could conceiveably find the max speed that the motor can support (assuming the software doesnt limit either current draw, or motor speed). The ICE would turn on to supply the current, but it would not help drive the reverse gear in any way, right? So if I can get the max car speed (reverse) and find out the proper reverse gear "ratio", I should be able to get max motor speed/current/power, and from there find the max foward speed for the car on EV!

I think the software limits max motor speed. I think a larger battery can supply the juice to run the motor at any speed, but the motor's electromechanics is prob the lmiting factor (too fast and the bearings burns up, to much current and the wires melts, etc).

From memory here, but if the Testla can get ~250miles out of a 50kWh battery, that's 5miles/kWh, and at California's electric rates (including transmission) of 21 cents/kWh (highest in the nation), that's equivalent to about 80mpg of gas at $3.50/gal, or 48mpg at $2/gal. That's like saying when gas is $2/gal, the Testla electric car would have had better "FE" than ... I cant think of a gas car with that FE...Honda Civic?

I think battery weight was/is the issue for EV, not electricity cost....IMHO all the way.

 

From what I've seen quoted here.... there is a physical limit on the motor too. That happens to be ~40MPH.

 

I believe that reverse max speed is 22MPH. I think I read that in the owners manual. The limit on forward battery only speed is the 10,000 RPM limit on the motor. Spinning the engine through the power split device is required above ~41MPH even though there is no fuel being consumed at times. We'd have to replace the motor with one rated for higher RPM's in order to get higher speeds in battery mode. Not likely to get that any time soon. As others stated, we would benefit more from having larger/more efficient batteries. That would only require changing the battery pack and probably a software update.

 

The correct answer to that question was 25mph but I'm sure mine only turns on after 35mph. Was that for the 2005 model?

 

Depends on the charge of your battery at the start - keep an eye on your battery level indicator on the Nav. If it doesnt look low and your ICE turns on, then it's because of acceleration requirements. I have gone ~2.1 miles (some coasting/charging downhill section ~1/4 mile), and two stop signs all pure electric...speed was about ~25mpg most of the way, on my 07MMH. This was quite level road, and very very soft on the accellerator.

(I did this at night, when no one was behind me. Also, the headlights were on -- if I had turned the lights off, I would have been truely, and dangerously, STEALTH mode)