Shifting to Park on long lights

Exactly. I don't really understand what "else" anyone was expecting? That's what it was designed to to do, and IMO it does that very well.

 

You might consider getting a Prius-aware scanner and monitoring MG2 and MG1 temperatures. My experience has been that it takes long, sustained, high-power operation to increase the motor-generator temperatures. The power electronics gets hotter quicker but they are water cooled.

Bob Wilson

 

I'm not talking about the electronics. I'm talking about the rotor and windings for MG2. It's not water cooled.
The only coolant inside the CVT is the trans fluid. While setting still and raising the amperage of MG2, without rotor movement can contribute to burn thought between the stator windings and rotor. Your Prius-aware scanner won't tell you anything about this. It's the same as causing a short circuit. Ever have a starter that wouldn't turn over even though the relay would energize ? It's that same thing. It gets a hot spot were the current leaks between the rotor
and winding. It stops it from turning.

 

Ok,

You do realize there is a gap between the permanent magnet rotor and the stator magnetics? They are not in contact in any way shape or form and no electric current flows through the rotor.

Source: Hybrid-Electric Vehicles

Still, I can see you are convinced this is a real problem and want to earnestly warn us about the risk:

How long does this take?

The reason I ask is I'm quite willing to do the experiment:

• mash the brakes as hard as possible
• mash the accelerator as hard as possible

This is the protocol for a forced charge and the engine will run until the traction battery fills and the engine turns off. Then the car will just sit there. Will it takes seconds or minutes or an hour to burn out MG2?

Let me give you some multiple choice options:

• 10 seconds
• 20 seconds
• 50 seconds
• 1 minute
• 2 minutes
• 10 minutes
• 50 minutes
• 1 hour
• 2 hours
• 5 hours

Which is the first one that forces MG2 to burn out?

The reason I ask is I'll leave the car running in the driveway and would like to know when to set the alarm clock. I'll take a nap.

Would you prefer I use something other than the brake? Perhaps up against a curb?

Please tell me how to burn-out MG2 and I will follow your protocol . . . and document it. But you must be specific and in particular, tell me how many seconds, minutes or hours you think it takes. Don't be shy as I am more than willing to repeat the experiment if you are willing to backup your claim by telling us how long it takes.

I know from my Prius-aware metrics that no static test will cause MG2 to fail. Still, I am willing to 'do the experiment' and document the results. Afterwards, we can discuss how to get better mileage and longer life from your Prius.

Bob Wilson

ps. I may have covered this in some of my earlier studies:
NHTSA Hearing June 23
NHTSA Hearing June 23
Prius Audio and Visual Data
Pulse and Glide
Prius Accident Log
Prius Accident Log
Buying 2003 Prius
Compare Prius, Jetta TDI, Insight, and Yaris at 55, 65 and 75 mph
2003 Prius
Magentic Loop Probe
Motor Generator Probe
2003 Prius
Detroit Auto Show and Prius 2010
Prius 2010 Impressions
Prius Hybrid Vehicle ECU
Toyota Georgetown Factory Tour Group
http://hiwaay.net/~bzwilson/prius/pri_PSD.html
Wilson PnG Test
Prius NHW11 Cargo Version
2003 Prius - Cold Weather and Transaxle
Swapping Accelerator Assembly
Prius Key Fob Study
Prius Neutral
PSD Model
HR 5734 Petition - "Bell the Hybrid Act (V01.01)"
Prius Power Study
Prius Shim Adjustment Procedure
Biased Anti-Hybrid Characteristics
2003 Prius - Cold Weather and Transaxle
Prius 03 Tank PG
NHW11 Prius Temperature Hack
Huntsville Prius Test Track
Cleaning Prius Throttle
Prius Type T Oil Analysis
Toyota Georgetown Factory Tour
Prius Flat Towing - AT YOUR OWN RISK
03 Prius Transaxle Temperatures
Prius Transaxle Vent
NHW11 Prius Warm-Up
Prius - UPS Project
http://hiwaay.net/~bzwilson/prius/test_model.html
Directory

 

No.
I stop it when my food is done.

 

Or the smoke escapes . . . (popcorn!)

Bob Wilson

 

Yes, I do. Have you never heard of it happening ? Armature windings can burn through without notice.
By holding the vehicle stationary on a hill, it will raise the amperage requirement without rotation of the rotor and could lead to it burning through. You can do whatever you like with your car. It wasn't meant to be a parking brake for lazy people

 

I'm not trying to be difficult but I would really like to know how severe any risk to our Prius might be:

I've tried every which way I know to break it including:

• reaching 100 mph
• maximum hill-climb, 8% grade, ~1.5 miles
• high-speed, +75 mph, high temperature, ~95F, with air conditioner

Since you've reported this risk, tell me how to verify it. Perhaps there is an engineering study that has some metrics and numbers? If you haven't guessed, I'm quite willing to do the experiment.

Perhaps this is something you've not seen with the Prius. Have you had problems with other electric motors that demonstrate this problem?

The reason for my curiosity is something posted in a Yahoo Group:

Source: Yahoo! Groups

Your description of what might happen to MG2 begins to sound similar to the nonsense a sales critter in the UK was spouting. We know the EU has a lot of anti-hybrid bias and it is trivial to find folks who like Top Gear, continue to rail about the Prius and any non-EU electric car. This is why I am curious about your source of concern about MG2.

What we have found in the past is Fear Uncertainty and Doubt (FUD) posting are often 'injected' somewhere and then these false claims are repeated time and time again. Usually they are repeated by people who may not know how our Prius work. Others come from people who had experiences with other products and similar technology and projected it into the Prius. I don't care as I just take each one as an opportunity to conduct a little Prius seminar . . . so we will all learn something.

Bob Wilson

 

I don't know how to verify it. I know it can happen to windings of any electrical motor. I'm talking about holding the rotor stationary (the load of the car on a hill) and forcing high amperage into MG2 without moving. If it can short to
the rotor, this will certainly accelerate it's demise. It's like holding a magnifying glass onto a landmine. Eventually, you'll get a result. It most certainly won't happen right at that moment, but over time by repeatedly abusing it, it will fail.
I use to see it a lot in the 80's and 90's with starters. We had to use a Growler to find the hot spot on the armature.


Not even close to what that knucklehead is saying.

Any electric motors are at risk of windings burning through. It's not something directly related to a Prius or excluding it.
ALLLLLLLLLLLLLLL Electric motors..That's all, not some or not the Prius.

 

From Toyota's Manual.

Hill-start assist control helps to prevent the vehicle from rolling
backwards when starting on an incline or slippery slope.
To engage hill-start assist control,
further depress the brake
pedal when the vehicle is
stopped completely.
A buzzer will sound once to
indicate the system is activated.
The slip indicator will
also start flashing.

 

Thanks. Still seems overly complicated in comparison to my Sonata.

 

It could also be that the Sonata has an idle RPM that is enough to hold the car and it doesn't really have hill assist
Just push down on the Toyota pedal after you stop. The hill assist will engage. A few seconds after you let your foot off the pedal, it will release and you can move without roll-back. It's simple, just get use to it.
I still bet the Snotta Good Car isn't equipped with it

 

...wow "Hill assist" I get it...being from hilly Pittsburgh my left foot is my intuitive Hill assist.
Anyways OP how about covering the brake with other foot during lights? I have to think this thru, but its one approach, right?

 

I'd just put the car in neutral and still keep my foot on the brake but not pressing as hard. I would just press hard enough so that the car doesn't roll forward or backward.

 

You should test the hill assist on your vehicle. It certainly can't hurt to try it

 

That only last 2 to 3 seconds

 

If you apply it and keep your foot on the pedal (you don't need to keep a lot of pressure on it after it's set) it will stay active. When you lift your foot off the pedal, it will turn off a few seconds after. As long as your foot keeps the brake
switch active, it will remain on. It only turns off when the pedal is completely released.

 

Oh I see what you mean. I'll try that. Thanks!!

 

N. works great at car washes

 

Really? You're going with that? You know, you can be a Prius fanboy without insulting other makes and models.