Prius Myths and their Rebuttals

[bwilson4web]

Hi,

I would like to address:

• 100% Electric
• Simpler Hybrid Design
• Other Hybrid Designs

100% Electric

The problem is energy density and that is driven by the oxidizing reactant. A battery oxidizes one electrode by reducing the other. Today's batteries are sealed so the oxidizing and reducing electrodes are the same collection of atoms when charged or discharged. So there is no change in mass as a function of state of charge.

The air-fuel batteries including the fuel cell, do not carry the oxidizer, they grab it from the air. Later, they toss the discharged chemistry overboard, the water. So the state of charge of any air-fuel battery is given by the mass of the unreacted electrode be it hydrogen, zinc, iron or any other battery electrode that can be oxidized.

Although a heat engine is driven by different, chaotic chemistry, it converts chemical energy into mechanical energy and again, tosses the by-products out the exhaust pipe. The functional equivalent to the state of charge is the mass of fuel in the tank.

So when we compare a sealed, oxidizing and reducing electrode battery to either the air-fuel or heat engines, the sealed batteries will always have lower energy density. This means you won't get the range on batteries that you can with these other opportunistic energy sources that take oxygen from the air and may or may not toss the exhausted reactants back into the environment.

Simpler Hybrid Design

As a general rule, simpler is always better but that tends to fall down when variable loads come into play. If you design a system to run at just one setting or speed, you can optimize the design and achieve amazing efficiencies. Thus large bulk carrier ships are able to transport huge amounts great distances very efficiently. But if the speeds and directions have to change a lot, it gets ugly very quickly.

Today we have terribly more complex computer systems than ever existed before with software to match. What the Toyota hybrid systems have achieved is a way to do in software what used to take very complex, mechanical analog systems to accomplish. Instead of building amazingly precise carburators and horribly complex automatic transmissions, simple actuators following computer control do it all. Best of all, they adjust as they wear to stay in peak efficiency until they just can not run any longer.

What this means is the Prius has fewer mechanical parts yet the reliability is as high if not higher than the competition. Furthermore, is terribly efficient. Best of all, software replication is a lot cheaper than trying to make precision parts.

Other Hybrid Designs

Depending upon the mission, hybrids need to be designed for the work they are going to engage in. For example, a hybrid garbage truck needs to optimize start-stop say 10-15 times in a block and that would be a different design from a vehicle that may go multiple blocks before stopping and starting. In short, one size does not fit all.

I'm a firm believer in the right tool for the right job and don't see other hybrid designs as being an "either-or" but rather overlapping the mission of a hybrid. If you need to carry 10 people about, it is a different design from a commuter only vehicle that may have just two seats. But also realize there is a big difference between "PowerPoint Engineering" and real products. Don't be fooled by the "Beta" versions of a hybrid.

CONCLUSIONS

I don't fault anyone for wanting to see 'something better' for that is the path to progress. But speculation is a lot easier than hard work of making product. Yes, imagination comes first but it must be followed up with a product, one that works. Otherwise, speculation becomes just another form of idleness.

Bob Wilson

[donee]

Originally Posted by electric_ave

i also wonder what the allure of the prius is. i had a 2001 insight that i drove into the ground, got over 100,000 miles on it. the car died when hurricane force winds dropped an oak tree on it.

i averaged about 60 mpg in that little sucker.

it was a simple car that was small, light, and had a manual transmission. it was what i thought hybrids were supposed to be.

the prius is a jumble of computers, high tech, buzzers, and screens. that's what i don't like about it (and that goes for both generations).

if toyota wanted to make a yaris or an iQ hybrid--i'd sign up for that. i just don't like how hybrids have shifted to such a overblown tech market, that's all. i'm more for a car that's transparent in how it operates.

Hi Electric...,

I always get a kick out of people with your opinion. Have you ever had a transmission from a standard car apart on your bench? There is not anything uncomplicated about them (double negative used for emphasis). They are very high tech in many ways, but mostly to do with the subtle details of forces and mechanical stack-up.

Its only because the parts are bigger than a transistor in a microprosesor chip that these things have been around longer. And its only because of computers (in CNC machines) that they continue to be cheap, and not outrageously expensive.

The Prius has a complicated system diagram, but a automatic transmission car has a complicated transmission. Even a manual transmission is not something you can give a high school graduate to disassemble, with any hope of getting it back together and run 100K miles. It takes some additional training.

The Prius transmission, if you take out the motors, is about the most mechanically simple power transfer device on any modern car.

[Road Fan]

NEW MYTH?

I have heard, and (mea culpa!) repeated, that Toyota's original design research for the Prius drive system was heavily funded by the Japanese government. However, I've not seen any documentation of that, at least that I recall. I've googled around a bit, but ... is anyone else aware of this, or did I get in in one of my adrenalin highs while driving my Prius over 80 mph?

Road Fan

[bwilson4web]

There is a 1972 TRW patent that describes how to build the CVT type transaxle Toyota used. Then there was a more recent patent that went into court to use small computers to handle the management task. That was the patent that Toyota lost in a Texas case.

Some of us think one of the best source of technology are USA patents. What is sad is these are not enough to sustain a domestic manufacturing industry ... Ford being one notable exception.

However, several USA government labs took NHW11 and NHW20s and conducted extensive reverse engineering analysis. They conducted fleet endurance studies as well as taking the cars apart and connecting them to dynometers. These reports are extensive, detailed and led to many of my experiments.

It is more accurate to say that US Government labs have laid out all of the basic engineering needed to make a Prius style hybrid. Ford had the good sense to work with Toyota and cross license the technology. Only GM and Chrysler pursued what remain dead ends or 'green wash.'

However, it is true the Japanese government funded research by:

• World class education - based upon year round schooling and first class education in math and science. Religous schools need not apply.
• World class healthcare - that keeps people alive and healthy well into their 80s and 90s. It is universal, not the anti-health system we continue to fund by Republican nonsense about socialized medicine and drugs.
• Universal retirement - so there is no question about whether you will have to eat cat food or live in a box when you can no longer work.

When you don't have to worry about survival or requiring unions for a living wage, life and retirement, you can focus on new products. Add to that a population with a high understanding of math and science and you've got a research lab that spans the borders of your country.

Bob Wilson

[llf1213]

Why would anyone need that much velcro? These guys sell it by the
hook and look and velcro the same thing?

[Omita]

8. Hybrids pose a threat to first responders.
Now that hundreds more hybrid cars take to our roads each day, some critics have wondered if public safety agencies should be
concerned about all those high-voltage battery packs zipping along at freeway speeds. Not too much. Turns out that a good amount
of training -- and, in case of fire, lots of water -- should be most of what a first responder needs upon arriving at an accident involving
a hybrid.
Knowing a few basic things about hybrids -- the location and construction of battery compartments, the color (orange) used to
designate high voltage cables, and the location of fuses that will isolate the electrical system -- is enough to help first responders
save lives and remain safe in the process.
Firefighters have coped with advancing automotive technologies for years, and they will skillfully deal with hybrid cars.

What should be added to this is Gas is one of the most dangerous elements a human comes in contact with every day. 1 gallon of Gas is equal to 10 sticks of dynamite.

[fuzzy1]

A now-deleted raid from what is most charitably described as 'another interest group' produced some real gems. Here is Hybrid Myths Q&A:

Hybrid Myths
Question: Will I be electrocuted if I touch a hybrid vehicle in a crash?
Answer: Other than if an external power source such as a down power line, no and this is no different than safety provided for a conventional vehicle rescue. The hybrid high voltage system is isolated from the body chassis.
Question: Will I be electrocuted if I touch a hybrid vehicle submersed in water?
Answer: No, while there maybe some electrical leakage, it will not be detectable simply by touching the body or frame of the vehicle.
Question: Is it necessary to call for a HAZMAT response if the high voltage battery pack is ruptured during a crash?
Answer: No, there is not enough electrolyte in the individual modules or in the entire battery pack. Leakage will be very minimal if at all, and usually will be contained with in the modules even if the casing was breached during a catastrophic crash. The electrolyte is considered a gel, having the consistency of a machine oil and is absorbed within a fiber material between the metal plates. Spills can be cleaned up with a suitable absorbent for a strong base, diluted with water and neutralized with vinegar.
Question: At a recent Toyota hybrid crash we saw a clear fluid leak and grayish vapor coming from the trunk, was this from the high voltage NiMH battery pack?
Answer: No, beside the HV battery pack, there are 12V conventional automotive batteries. In a severe rear end or offset crash the 12V battery maybe subject to impact. The reaction seen was similar to that of a conventional vehicle when the 12V automotive battery is ruptured during a crash.
Question: At a crash, is there a chance that the high voltage system will electrify the vehicle's body chassis?
Answer: No, there are several automatic sensory devices that will stop the high voltage flow. The SRS ECU upon activation of the airbags, will also send a signal to the hybrid system computer, the computer will then open the high voltage relays to the HV high voltage battery pack; preventing the high voltage flow from the battery pack. In essence, there are checks and balances to prevent this situation.


The rest of the page includes more information for Emergency Responders. Unfortunately, the aforementioned raid displayed evidence that these myths persist within the emergency response industry.

[fuzzy1]

Another article from the previously mentioned thread: Hybrid Vehicles: Separating Fact from Fiction, from Fire Engineering.

"... Many myths and misunderstandings concerning the dangers of these vehicles’ new technology have circulated among emergency responders. Separating fact from fiction is paramount to enable emergency responders to properly handle these vehicles at incidents.

Some current myths about hybrid vehicles include the following:

• Hybrid vehicles are just a fad.
• A damaged hybrid battery module will leak a significant amount of fluid.
• Touching a hybrid that has been in an accident or is submerged will result in an electric shock.
• The high-voltage power system is difficult to disable.
• The high-voltage wiring hampers vehicle extrications.
• Hybrid vehicle fires require special equipment."

"... Although the media and other entities have hyped the dangers of hybrids, proper training and understanding of hybrid technology make them one of the smaller issues with which the fire service must contend. I drive a hybrid and am not concerned that I am placing myself, my family, or my fellow firefighters in unnecessary danger." (emphasis added)

More articles at a Hybrid Vehicle Info page.

[quadracer1014]

Originally Posted by fuzzy1

Another article from the previously mentioned thread: Hybrid Vehicles: Separating Fact from Fiction, from Fire Engineering.

"... Many myths and misunderstandings concerning the dangers of these vehicles’ new technology have circulated among emergency responders. Separating fact from fiction is paramount to enable emergency responders to properly handle these vehicles at incidents.

Some current myths about hybrid vehicles include the following:

• Hybrid vehicles are just a fad.
• A damaged hybrid battery module will leak a significant amount of fluid.
• Touching a hybrid that has been in an accident or is submerged will result in an electric shock.
• The high-voltage power system is difficult to disable.
• The high-voltage wiring hampers vehicle extrications.
• Hybrid vehicle fires require special equipment."

"... Although the media and other entities have hyped the dangers of hybrids, proper training and understanding of hybrid technology make them one of the smaller issues with which the fire service must contend. I drive a hybrid and am not concerned that I am placing myself, my family, or my fellow firefighters in unnecessary danger." (emphasis added)

More articles at a Hybrid Vehicle Info page.

those myths you speak of are not myths. They are actual USDOT and NFPA rules that we as professionals are required to follow.

The articles you quote are relevant in light crashes only.

We professionals have to follow federal state and local procedures regarding hybrids.

The toyota and other company ERG books are nothing more than glorifed maps of wiring locations to us. And even then they are only valid when the car is structurally intact

Key portions of that article

Never overhaul high-voltage components since there is no guarantee that the system is deenergized. The effects of fire can render system safeties inoperable. Live fire testing indicates that these components can remain live after exposure to fire.

Fact in a heavy collision like the one pictured in the article. You cannot tell where the wiring is anymore. You cannot de energize it using the methods in the toyota erg either

more interesting points from the article

Avoid any contact with the electrolyte because of the potential for human tissue damage. If necessary, contact CHEMTREC® [(800) 262-8200,

Bear in mind I have seen this happen twice this year alone

[fuzzy1]

Originally Posted by quadracer1014

those myths you speak of are not myths. They are actual USDOT and NFPA rules that we as professionals are required to follow. ...

Q.E.D.

To repeat:
Standard PriusChat challenge: Pictures, or it isn't true.
Translation for you: URLs to documents, or it isn't true.

I'm painfully aware that NFPA charges significant fees for its standards, but the least you can do is cite specific standards and chapters. USDOT should have everything freely available online.