Reverse on uphill

<div class='quotetop'>QUOTE(nrb @ Apr 29 2007, 01:17 AM) [snapback]432003[/snapback]</div>

I in no way mean to be smart, and also want to read a real answer to your question, but how about parking downhill with the car facing the opposite way?

 

<div class='quotetop'>QUOTE(ystasino @ Apr 28 2007, 10:26 PM) [snapback]432027[/snapback]</div>

I am being smart: How about moving south of the equator so that you are pointing the other way....

 

I don't think the Prius should have any issues with not having enough power. As long as you're not totally bottomed out on the SOC, there should be plenty of juice to back up the driveway.

 

<div class='quotetop'>QUOTE(nrb @ Apr 29 2007, 01:17 PM) [snapback]432003[/snapback]</div>

How about reverse in a zigzag manner (just like tacking in a boat)? This has the effect of lowering the 'angle of attack' of the drive wheels. Turn from lock to lock as you reverse, using the brakes when necessary to stop you from ever rolling forward. The front of the car will swing from side to side, but after each "tack", you'll notice that you're slowly edging your way up the incline.

 

<div class='quotetop'>QUOTE(nrb @ Apr 28 2007, 10:17 PM) [snapback]432003[/snapback]</div>

Reverse is electric only. However, if the battery does not have sufficient charge to drive the distance in reverse, the gasoline engine will turn on and generate the needed electricity (there are two motor/generators). Just press the accelerator as much as necessary to get going when you back up and the car will do its thing.

 

When backing up our 2007 the ICE comes on most times.

 

<div class='quotetop'>QUOTE(nrb @ Apr 28 2007, 10:17 PM) [snapback]432003[/snapback]</div>

Why don't you let your wife try it? She probably won't be thinking about what is powering the car and she will just back up the hill with no problem.

 

<div class='quotetop'>QUOTE(nrb @ Apr 29 2007, 08:56 PM) [snapback]432291[/snapback]</div>

I have not experienced this problem, but if you think the problem is a low charge, then when you return from a trip, before shutiing down, put on Emergency brake, put car in drive, step on foot brake just for self assurance and then....step on the accelerator! HV Battery will charge in a minute or less into the green zone. This is all selfregulating and wii not hurt a thing. In the morning you should still have a good charge. AndyPrius

 

The problem is real. I stalled in the middle of a steep hill while climbing back in reverse, so I learned from experience. The trick is to floor the gas pedal, not just hold it part way; part way won't work on a steep hill, you have to floor it.

If the hill is long, the ICE will come on to supply power to the electric motor because the battery will drain quickly.

 

<div class='quotetop'>QUOTE(jamarimutt @ Apr 30 2007, 12:00 PM) [snapback]432591[/snapback]</div>

Are you sure the ICE will turn on? As I understand it, it's directly geared to the PSD; when you're going in reverse the ICE spins in reverse and thus can NOT run until the car is stopped or moving forward.

 

<div class='quotetop'>QUOTE(Pinto Girl @ Apr 30 2007, 03:48 PM) [snapback]432724[/snapback]</div>

Yes, the ICE will run, but only to generate electricity which is then fed to the electric drive motor. It won't drive the wheels directly, but it can certainly supplement the power available.

 

This sounds like a traction control problem, not a power issue. The electric motor on the Prius provides about 70 hp with full torque at zero RPMS; it could burn the rubber off your wheels without even breaking into a sweat.

Tom

 

<div class='quotetop'>QUOTE(Tempus @ Apr 30 2007, 03:14 PM) [snapback]432741[/snapback]</div>

Can you explain to me how the ICE can run while the car is going backwards, even to generate electricity?

If the car goes backwards, the ICE spins backwards, right?

Soooo...

That would mean that, unless the ICE can also *RUN* backwards, it can NOT be charging the batteries as you suggest.

 

<div class='quotetop'>QUOTE(Pinto Girl @ Apr 30 2007, 05:16 PM) [snapback]432778[/snapback]</div>

:blink: [short pause while I decide if you are pulling my leg...okay, I'll bite] The ICE spins the gear carrier with the planet gears. It can spin at any time, regardless of whether the ring gear attached to MG2 and the drive train is spinning forward, in reverse, or standing still, as long as the sun gear attached to MG1 is free to rotate. If MG1 is allowed to free wheel, the Prius is essentially in neutral. Backing up is done by applying a reverse drive to MG2. All of the backup torque is supplied by MG2. If the ICE is spinning, then the little planet gears will spin even faster than normal, since the ring gear is turning backward. The planet gears spin the sun gear which is attached to MG1. If a field is applied to MG1, then MG1 acts as a generator, making electricity to charge the battery and/or drive MG2. The ICE is clearly still turning in the normal direction.

Tom

 

<div class='quotetop'>QUOTE(qbee42 @ Apr 30 2007, 05:13 PM) [snapback]432776[/snapback]</div>

It is not a traction control problem. The electric motor has enough torque to climb up a steep hill in reverse, but you have floor the accelerator to use use it; pressing the accelerator slightly or half way won't work, if the hill is steep enough the car will stall.

Don't be afraid to floor the accelerator, the car won't shoot back out of control as may happen with a regular car. The Prius will back up the hill at a constant slow speed, and when the battery charge drops low the ICE will come on to supply the charge needed.

 

<div class='quotetop'>QUOTE(qbee42 @ Apr 30 2007, 05:21 PM) [snapback]432813[/snapback]</div>

No joke; obviously I still have trouble visualizing how things really work down there. Thank you!

 

<div class='quotetop'>QUOTE(Pinto Girl @ Apr 30 2007, 04:06 PM) [snapback]432832[/snapback]</div>

Hope this will help.
http://www.toyota.com/vehicles/minisite/hs...l?noreloadredir

 

Remember that if the engine is producing torque, 72% of that is
going to try and drive the wheels FORWARD. Therefore MG2 has to
fight not only that but also the hill. To do that, MG2 needs to
receive power -- from the battery and/or MG1. But the harder you
load down MG1, the harder the engine cranks against both it and
the wheels! It seems like a total paradox, but the levels can be
controlled in a way that eventually yields net axle torque backwards.
.
There were, however, rumors of people not being able to get out of
parking spots on Lombard St...
.
_H*