What would happen?

No.

 

Is it flat?

 

The battery or the tire?

 

:boink:What? Are you for real? What are you trying to accomplish?

 

instead of us thinking that you may be an idiot, you would prove it.

 

Somewhere there is a job for a diplomat with your name already on the desk morpheusx.

 

after careful consideration and consulting with a research scientist friend at rocketdyne, we have concluded that it WOULD in fact charge the battery, but not in your garage.

 

I'll give you a serious answer. If you put your Prius on rollers, powered it up, applied pressure to the brake pedal, and applied power to make the wheels turn you would generate electricity and charge the battery. Note, however, that the amount of energy required to turn the wheels would be greater than the amount of energy stored in the battery during the recharging process. There isn't a free lunch - not only that, but you can't break even.

Tom

 

I wanted to know why you would want to charge the battery.

 

Actually, I don't think you need to apply pressure to the brake pedal. As long as you don't apply pressure to the accellerator pedal you'll get regen coast.

One problem is that regen doesn't occur at low speeds (coasting or braking). I can't remember the exact speed, but I think you need to get the wheels spinning at somewhere around 8 or 9 MPH to begin charging the battery. If you jack the car up and turn the car on, the wheels should start spinning on their own up to about 8 MPH or so from the built in "creep". What you'll need to do is push them faster than they are already spinning.

Stevoid said "manually rotate", I'm not sure I want to grab hold of a wheel spinning at 8 MPH with my hands. Stevoid also mentioned raising and spinning only one tire. I'm not certain how a differential works, but if the drive shaft is attempting to push both tires at 8 MPH and only one tire is moving, wouldn't that tire be spinning at somewhere around 16 MPH? So if one tire is held still and the other is spun, would you need to spin it above 16 MPH to get regen? I also wonder how the traction control would respond to 1 tire spinning freely. when it "cuts power" to the wheels, does it also cut out any potential regen? If so then raising one wheel will never be enough, you'll have to get both spinning together at similar speeds.

I like Tom's idea of powered rollers. It creates a sort of inneficient "plug-in" hybrid. You plug in the roller's motor. You loose a bit of energy converting from electrical to kinetic driving the roller's motor. Then you loose a bit of energy to friction of the various moving parts and the interface between the rollers and tires. Then you loose a bit of energy converting the kinetic back to electrical in the vehicle's generator. Then you loose a bit of energy to internal electrical resistance in the wires, inverters, and battery. Finally, you lose a bit of energy converting from electrical energy to chemical potential energy in the battery. After all those losses, assuming you feed enough energy into the roller's motor, you charge up the HV battery a bit. Unfortunately, the Prius battery doesn't have the capacity to get a very signigficant boost in MPG beyond a mile or two when it is charged to the vehicle's limit (80%) as compared to when it is discharged to the vehicle's limit (40%). So given the amount of power you'll need to get the battery charged up, I'm not sure it would be worth the effort and expense.

Still there are many here at PriusChat who spend money on an EBH and then suffer the energy losses to operate it to boost their MPG for the first few miles of every day. If it was cheap enough to set up, this roller-charger might be a way to boost that first 5 min. MPG a bit more.

Interesting.

 

No, because the Prius has an open differential to allow the front wheels to turn at different speeds while making turns. So if you rotated one wheel, the other wheel would rotate in the opposite direction.

 

Unless you put the car on a kind of dyno rig, I don't think you'd be able to do much of anything... if you only spun one wheel a car with a "normal" differential would spin the other wheel in the opposite direction as stated previously. The Prius, however, would most likely interpret the situation as a case of lost traction and would kick in the VSC, not permitting any load to either MG-1 or 2, and you would quite simply be spinning your wheels (pun most definitely intended).

 

Ok, so here is the deal:

1. You have to block one wheel so the differential won't spin.
2. You have to be in "Ready" so the hybrid electronics are working.
3. The engine will run long enough to bring the coolant temperature up to spec.
4. You have to be ready to grab a spinning tire as the "creep" function tries to move the car at about 2-3 mph. Double that rpm with one wheel blocked.
5. You have to apply at least 500 watts of power "forward," making the wheel turn faster, to handle the "house keeping" power drain.
6. Per Wikipedia, a normal human would produce about 200 watts and a world-class athlete could burst to 1.6 kW just prior to complete exhaustion. One horsepower is 745 watts.

Other than these details of implementation ... it sounds like a grand experiment and weight loss program.

Bob Wilson

 

Thank you for this last series of serious and thoughtful responses.

It is a bit shameful that our first responses to a new member's very first posting are so dismissive and insulting.

 

A lot of great inventions came to be because someone asked a question that everyone else thought was crazy.

 

How about rollers powered by falling water at Niagara Falls ? Just give us some special parking spaces to recharge...


But seriously, why not couple a big windmill to the wheels in places with good wind ? Stationary recharging only of course...

 

I'm not dismissing the OP I just want to know, why do you want to charge the battery.
Normally my battery is at the top of the purple when I stop so not sure there would be much capacity to add much charge.

 

Yeah but . . .
What would the traction control do during this scenario?????


Oh, and by the way . . .

WELCOME TO PRIUSCHAT stevoid.
:madgrin::madgrin::madgrin: we're really a harmless bunch. :madgrin::madgrin::madgrin: