Fast Charging the NiMH battery - COOL TIP

<div class='quotetop'>QUOTE(efusco\";p=\"71647)</div>

First I'll ask...what chain?

Next, AFAIK, there is not stress on the system at all (other than the battery and the environment)....Keeping the brake depressed cuts power to the wheels and allows just MG2 to spin and charge the battery...you can see this on the monitor as it occurs.

There is a chain that connects MG2/ICE to gear reduction/wheels (Oak Ridge Nat Lab Report, ORNL/TM-2004/247 pgs 11 and 12).
Haven't tried what was posted that's why I asked if Motor ICON was on.
Would seem if brakes are applied and MG2 is active that it would put stress on drive system.
If MG2 is not engaged then it shouldn't matter.
[/b][/quote]

 

I'd love to see what happens to the MG1 temp. I'm sure it just zooms up scale like crazy. I'd try it and see what the MiniScanner say's but just can't see the need to do it. Other than burning gas for nothing what condition does that HV battery get to, to need this kind of charging. I've driven up 6000' passes and never experienced a need to force charge the battery. Why abuse the thing for nothing?

 

hehe.. a lot of us seem to bash this more than support it. There is no need. For us who put the prius through the climbing test.. and some of us do more test... it's a very good car and you never need to do this charge.

if you are doing racing (car is not designed for this ) or autocrossing ( same ) then this feature could potentialy be useful to you.

that's all though. everyone has expressed that it's most likely bad for the components of the car.

we do seem to repeat ourselves a lot though.

 

Hi Evan:

Yes, there *is* a chain.

If you reference the detailed Oak Ridge National Laboratories / DOE at:

http://www.osti.gov/bridge

and search for document ORNL/TM-2004/247, you will find a very detailed description of the internal parts of the HSD.

In particular, page 11 Fig 2.6 clearly shows the drive chain and the gears.

 

I can understand the concern about the stress on the gears and chain. If you are revving the engine, then more torque is applied to the ring gear, even if it isn't going anywhere, and spinning MG1 (it's MG1, MG2 is connected to the ring gear, remember?).
I don't think it is a cause for concern. The HV ECU won't allow the ICE to over-rev MG1 anyway. By the way, the same situation applies to being in Park. The pawl locks a gear to the drivewheels.

And Ig-On does not enable the system relays, so you can't drain the HV batteries any more than ACC.

 

I tried that document search but I can't find that document. Doing an 'easy search' for ORNL/TM-2001/247 (a completely unrelated document with a similar-looking identifier) returns a document, so I know my search method can search for those kinds of documents. Searching for the document you said, ORNL/TM-2004/247, says "not found".

 

Wth?

I downloaded this document and it *does* exist! Let me look into it and get back to you.

 

RE: the chain

From out International Album:

http://priuschat.com/forums/album_pic.php?pic_id=659

http://priuschat.com/forums/album_pic.php?pic_id=663


To the moderator:

Unlike the vast majority of the other threads, we are not being supportive or accepting of one another. Rather than being open we have become quite opinionated.

I suggest that this thread be locked or preferably, deleted (if the original poster is amenable to this), such that we can move forward and get back to the welcoming and supportive environment that has been a splendid trait of this site.

-bob

 

The title of the document I downloaded last year is:

"EVALUATION OF 2004 TOYOTA PRIUS HYBRID ELECTRIC DRIVE SYSTEM
INTERIM REPORT"

And the document filing number is: ORNL/TM-2004/247

I did a search at the OSTI bridge site and it claims that document number no longer exists. A search using the title brings up a document on fuel cells: "Fuel Cell Handbook." An obvious database error here.

However:

Point your browser to Oak Ridge National Laboratory at:

http://www.ornl.gov

And on the left pane click on "Science and Technology" and "Publications Database."

On the blank field next to "Keywords" enter:

EVALUATION OF 2004 TOYOTA PRIUS

And it should find it. Click on "full text" and it should give you the Adobe pdf.

Note if you go to the ORNL home page and enter the same search text into the search field on the right pane, you will get multiple listings, including a pdf with the Final evaluation on thermal management.

 

Ah don't worry about it, it's only Junior Alzheimer's. I get it all the time. Us cranky 'ole coots have to stick together.

 

Evan:

That's a fine idea. We'll prototype and patent the system, sell it to Toyota for a zillion dollars, and then when we're ready for The Cranky Ole Coot Home, at least we'll be shoved into a nice one where the nurses don't mind being pinched in all the wrong places.

 

Well, I don't think I would recommend this charging tip, and based on my very short experience with it in my garage a night ago, I wouldn't want my dealer doing it either.

With the car in drive, and the parking break on, left foot on service break, I added slight pressure to the accelerator with the right foot. The Prius really wanted to go. I was under the impression that this particular procedure would have the vehicle actually sense that the breaks were on and that I the driver didn't want to go anyplace, except to rev up the engine. It felt like I was doing the same procedure to an automatic, like in left foot braking. Anyway, the diagram on the MFD, although sometimes a bit anecdotal, indicated that electrical power was going to the wheels, along with ICE motive power, and that electrical power was also being returned to the battery. I would agree with the MFDs conclusion because the car really did want to move forward.

I discontinued this exercise rather quickly due to the feel of stress and decided that it was not advisable under any circumstances to do this.

I have never had an issue with the vehicle's SOC while driving. It does what it does very well and I'm happy to leave it at that.

I don't wish to ridicule or harm the original poster, but this just doesn't seem like a reasonable procedure under any circumstances.

 

The procedure is to keep the left foot on the BRAKE (not the parking brake) and then push the accelerator with the right foot.

 

He *did* have his foot on the brake. In most countries, when one refers to the "service" brake that means the "brakes."

BTW: I tried that stunt at a red light today after work and it felt almost the same as "power braking" a regular automatic transmission. I'll never do it again.

 

Thanks for clarifying to all what I meant. I'm not an engineer, and I don't play one on TV, however I recall service brake being the accepted descriptor for regular brakes, and thought I'd use it to be specific and clear.

 

Oh, it's absolutely the correct description in The Rest Of The World. Here in North America you might be better off saying "that doohickey that makes you stop."

 

hehehe :iagree:

 

why would you need to charge the battery anyway? going uphill if you run to low of batteries just means youll go all ICE and burn up gas that way rather then burn up gas sitting stationary. I doubt toyota would sell a car that couldnt drive up a mountian on public roads.