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Rescuers Prep for Hybrid Car Accidents
mykepredko writes "I've driven a Toyota Prius for two years now and found this CNN article regarding the training required to rescue people trapped in hybrid cars to be slightly alarming. As an EE, I would expect that the electrical system is designed to be as well protected and fail-safe as possible in an accident, but if I'm ever in an accident, I'll make sure that any responders are wearing rubber gloves and boots and if any cutting is done, the roof is the only area they touch." Toyota has an accident guide indicating that if the airbags deploy, the hybrid battery pack should be automatically isolated.
vs. dumb-asses.
500 volts? 45 volts is enough to kill you... at 10 amperes!
Seriously, aren't we nerds, or something?!
In the future, I would want to not be isolated from my friends in the Space Station.
That's still a concern, hybrids have both a gas or diesel engine and battery power.
Trolling is a art,
From the article:
The battery powering the electric motor carries as much as 500 volts, more than 40 times the strength of a standard battery.
Karma: Can there be a void?
.. -. - . .-. .-. --- -...
Extended comments at Gizmodo makes it clear that this is 99% rumor/FUD. Does anyone bother chacking the facts on these things before they're posted?
OK,
- B
http://www.bradheintz.com/
- updated
The standard place on race cars for electrical cut off is the RR corner, normally on the rear panel. Normally a big red switch. Sometimes a push/pull rod conected to the switch mounted in the trunk. This is because most race cars have their battery mounted in the RR corner of the trunk/boot.
Next generation hybrids--such as the Lexus V6-hybrid SUV--will have the eletric motor running the rear wheels while the gas motor runs the front wheels. This should cut down on dangers as the motors will be quite isolated from each other.
However, in ANY car wreck, a badly mangled car is dangerous.
As the owner of a 2004 Prius, and being an engineer, I have never felt in danger.
First, the High Voltage system is isolated from the car body completely. Not even "ground" is shared. The cables and parts are shrouded in tough orange plastic.
Second, the article is incorrect on two points: the battery is only 200+ Volts, not 500V. The 500V is only between the inverter and motors.
Also, there are no high voltage components in the doors.
Because the airbag accelerometers are used to monitor whether the car is in an accident, the main battery relay shuts off right next to the battery long before any metal starts twisting its way into high voltage areas. The bigger danger is the battery (several NiMH cells) being split open, but it is protected by its location and special shrouds.
My biggest fear in an accident is that the E-personnel are scared into paralysis by rumors, and don't rescue me.
BTW, you can see the Toyota Emergency Responder guide at http://techinfo.toyota.com/
That 20,000 volts for the HID isn't a problem, because the wattage is low. If you stuck your finger in it, it'd shock you for an instant, and then not be able to provide enough current to keep shocking you. You'd be 100% A-OK Super-great deal A+++
-Jesse
Nothing says "unprofessional job" like wrinkles in your duct tape.
Nope, most any person who is trapped - dead or alive - has to be pulled out, and since we are the only ones trained to do it, guess who gets called out?
The difference is that we generally wouldn't go emergency if it was a definate body recovery. But IO have certainly cut my share of dead and alive patients out of cars.
The thing about all of this is that, in an accident bad enough, you can't guarantee any emergency system within the car is going to work. I don't care *what* the manufacturer says, if it were my guys they would be wearing any protection we could give them.
The problem isn't just limited to Hybrid cars. Think about the cars that have side-impact airbags, air cushions, etc. Anywhere we want to cut could contain within it an airbag ready to deploy. Worse, even those manufacturers don't have a standard for how long before a system is deenergized. At least with steering wheel airbags we can put a special cover over it.
Random Musings
I don't necessarily believe the original intent of this poster was missed by the moderators. If by his posting his intent was to indicate that the gasoline companies would like nothing more then to discredit the burgeoning alternative energy cars then I think he suceeded. Not that the article is any way incorrect.
I did research on solar power cars back in the late 80's as part of an independent research project at my college. The more I dug into the subject the more I began to discover that all the juicy technical information regarding the subject was owned either by gasoline or oil companies. I was blown away. It was the first time I was confronted with the realities of business. What can I say call me naieve.
Sir, there is a dragon outside with an armful of armor. He's inquiring if we offer free refills.
But after an accident, any part of the wiring harness could be energized relative to the frame -- you just don't know, for example, if the dome light circuit is going to happen to be connected to the same bank of circuits that were smushed into the Big Orange Cable in a front-quarter collision that also happened to damage the fail-safe circuit breakers.
It's a big deal -- I imagine your training is similar to what the rural fire volunteers are getting here in Colorado: if it's a Prius, don't touch it!
Reminds me of the college kids who like to play with radiation warning labels: ``heh-heh. My laptop has a radiation sticker on it! Cool! heh-heh.'' The problem is that if you get in (for example) a car accident and one of those labels is visible anywhere around the car, there is no first aid for you until the radiologic response unit arrives from across town.
You, my friend, watch way too many movies.
Back here in the Real World, gas tanks are hardened, so that only the most violent shock would produce a rupture, and are also positioned at the opposite end of the vehicle from the major source of ignition (ie the engine).
You really have to try really hard/be very (un)lucky to get a car to explode.
Ask 8 slackers a question, get 10 awnsers (a citation, but I can't remember from who)
Actually, you have been watching too many movies. Gas tanks can't blow up. Gasoline itself is not explosive, only gasoline vapor that has mixed with air is explosive. What this means is that the gas has to first leak all over the place to create sufficient surface area for it to evaporate quickly, and then it has to be ignited. It unfortunately happens, but it's not nearly as easy as most people think. Battery acid also has to evaporate in order to be explosive, and off the top of my head it probably has lower vapor pressure than gasoline.
They still exist. They are called seat belt pre-tensioners and are used on lots of vehicles now. The best occupant protection sytems tend to have belt pre-tensioners.
Loud Pipes Save Lives. If a trucker can't hear your bike over the sound of his downshifting truck engine with the exhaust brake on, you're a "small model of the barren earth, which serves as paste and cover to" the freeway. (apologies to The Bard, Richard II act 2 scene 3)
Similarly, these silent cars perhaps ought to have a noisemaker, one that's user activated, with a button or something.
Oh, wait, that's called a horn.
Gasoline is only combustible when blended with air in a fine mist. That's why cars have either carberators or fuel injection systems. Besides, Hybrid cars have gasoline and a high-voltage power source to set it on fire.
There are two problems with the above: it neglects the rate of energy transfer and the barrier to it. With a gasoline engine, both are reasonably high unless someone's walking around with matches, and emergency crews are smart enough not to smoke. The risk of shock is higher than detonation.
Also, there's no analogous concept of capacitance for gasoline. However, if the wrong cable gets severed, your ass is fried with an electric. Also, because stored electrical energy is less obvious than a puddle of gasoline, it's harder to avoid.
So there's about 5 reasons why one need fear hybrids in a crash more than regular cars
Oh, BTW, did you ever wonder why your old dial-up telephone modem made those high-pitched annoying tones exactly the same way no matter what kind of modem you had? Those tones are three (maybe 2, I forget) distinct ring tones that instruct the repeater on your telephone line to shut off the noise on the line to set up lossless digital communications.
Another load of premium male bovine excrement from out friends in Texas and Munich/Detroit.
My THIRD Prius, an 04 (I've owned an 01 and 03 - both completely problem-free), is currently sitting in Port Newark. I am also a retired rescue captain so I can state with some authority that Prius fundamental design is such that it would take a deliberate act of stupidity for a rescue technician to manage to make contact with both the positive AND negative high voltage leads at the same time since both are ground-isolated and separately encased in conduit.
In real-fife rear-end accidents, only ONE Prius battery was damaged and it's safety issue was some minimal leakage of electrolyte; NOT "Deadly High Voltage"!
In fact, the Japanese national fire safety bureau (the official name escapes me at the moment) insisted that Toyota place the HV conduit inboard far enough that the "Jaws Of Life" can't possibly make contact in one or two "bites".
Sigh...
"I don't understand it???
I'm afraid of it!
KILL IT!!!"
T_O_M
The Prius uses NiMH batteries. They have a highly caustic (pH 13.5) electrolyte, but other than that are apparently non-toxic. Vinegar or Boric acid can be used to neutralize any electrolyte that leaks, but leaks are not likely since the solution is absorbed into the cell plates and shouldn't normally leak even when the battery module is cracked.
THIS LINK provides a description of how the Prius' drivetrain uses the gas and electric motors in tandem.
There are indeed two batteries. The last time I rode in a Prius, I accidentally covered some ventilation holes in the shelf behind the back seat with some paperwork.
In fifteen minutes, the car was non-operational.
Turns out the back battery is the one that does the electric motor, and it really doesn't like to get hot, ever. Removed the offending paperwork and it was back to normal almost right away.
They will never stop until somebody makes the
Most truck/cycle accidents are caused by trucks turning across the path of cycles. If the bright headlight isn't enough to make the truck driver aware of the cycle, noise in the cycle's wake isn't going to help. It is especially not going to help if the trucker rides an unmuffled bike on his off hours and can't hear very well himself.
Your friend needs to try driving it harder. Its easy to make the battery run out of juice... keep your foot down to the floor for a mile or so. When that juice is gone, the car is slower than a busted down Geo Metro.
I heard a news segment on NPR a few months ago about hybrids, and they said that Ford was far enough behind in hybrid technology that they were licensing some hybrid technology from Toyota. I don't know if that covers this, though. Honda has already had hybrids here as long as has Toyota.
I struggled for days and days and all I got was this lousy sig.
power = voltage * current
energy = power * time
No idea what you're talking about. Drive-by-wire systems are typical low power 12-soon-to-be-48 volt circuits. Drive-by-wire is just sensor request vs mechanical activation.
KeS
Needs fuel plus oxygen plus ignition, which 800 apparently had.
Motor vehicles have vapor, but not the ignition and usually not the oxygen.
Flight 800 had a mostly empty center tank of approximately 13,000 gallon capacity. Between 500 and 1,500 times that of a normal car.
It had approximately 50 - 100 gallons of fuel in it, enough to create good vapor for the remaining 13,000 gallon capacity.
That fuel was also not gasoline, but kerosene (more or less) a very different substance. So the explosive air/vapor mixture yields very different explosive energy in jet fuel vs. gasoline.
So you are comparing a fire-cracker to a friggin MOAB and saying "see they both can explode, therefore the firecracker is just as dangerous as the MOAB."
It's still safe to say that after all the cars on the road and all the collisions and so on that gasoline when contained in the tank is resaonably safe.
I am sure if you had Googled, you'd have realized your comparison doesn't work at all.
Did anyone else wonder why is there serious power in the doors? Do you need 500V for the electric windows?
/. story, no, there is no power in the doors. On page 8, a diagram clearly shows the high voltage cables running under the floor on the driver's side. There are no high voltage cables anywhere close to the doors.
From safety manual linked to in the
From the article: "They know not to cut into a hybrid's doors -- that's where many of the cables are -- and to peel off the roof instead."
In all likelyhood this article is a big piece of FUD written by people who've not taken the time to research the issues and are are trying a sensationalist approach to attract more readers.
Yes, but the super efficient Honda Insight can credit most of its fuel efficiency to extremely light weight, 1800 pounds (about 825 kg).
The Honda Civic Hybrid is only slightly more fuel efficient than the Civic HX Coupe and not nearly as efficient as the similarly sized Toyota Prius hybrid.
Honda is ahead of everyone save Toyota, but Toyota still has quite a lead.
Toyota isn't taking this one sitting down.
Toyota Press Release
Toyota Prius Engine Safety in the Event of an Accident
For Immediate Release
(05/04/2004) Torrance, CA
The Toyota Prius gas-electric hybrid vehicle has many safeguards to help ensure safe operation for drivers and protection of emergency response professionals in the event of an accident. The high voltage batteries are contained in an extremely strong protective case located in a portion of the vehicle very unlikely to be penetrated in a collision. Drivetrain management computers continuously monitor all system functions performing hundreds of tests each minute. In the event an abnormal condition is detected, all high voltage circuits are disabled and high voltage is contained inside the protective case.
Further, two safety mechanisms are in place that shut off the engine and disconnect high voltage if an airbag is deployed or if there is a sudden deceleration indicative of an accident. High voltage cables and components are heavily insulated, shielded, isolated and the cables are painted bright orange for easy identification. The controller box is a sealed unit and has warning labels.
To reassure emergency response professionals when the Prius was introduced in 2000, Toyota placed advertisements in trade publications and sent letters to industry organizations announcing the availability and dissemination of Emergency Response Guides. Today, all Emergency Response Guides for Toyota's alternative fuel vehicles, including Prius, RAV 4 EV, CNG Camry and Highlander Fuel Cell Hybrid are available at Toyota's technical information web site and Toyota continues to advertise in appropriate professional publications.
Electrically driven Toyota vehicles like the Prius, RAV 4 EV and e.com have been available in the U.S. since 1998. Like all vehicles, they can be involved in emergency situations. They have established a good track record for electrical safety and we are not aware of a battery case breach or any personal injury in the U.S. related to hybrid or EV electrical systems.
# # #
Contact:
Toyota Product News
Apparently Toyota is pretty protective of it's technology.
$ man woman *
-bash:
FYI, most production cars are incapable of 200. Usually drag is the limiting factor. A late model high-end Camaro or Firebird, for example, with minimal upgrades (chip, intake, exhaust type stuff) will generally drag-limit itself around the 155-170 range dependant on a few factors. A 'Vette in the same boat might make 180-185-ish due to it's better aerodynamics. In any case, even on a wide open empty road, anything over 150 is pretty fucking scary in a production passenger vehicle of any kind - especially taking into account unpredictable things like rocks and small animals that might be in your path.
And generally, you don't get arrested at 100 either. I routinely hit 120 in the major city that I live in when traffic opens up enough to allow it without being overtly rude to other drivers. A little knowledge of where the police usually set up speed traps in your city, combined with a radar detector and a vigilant eye, can usually keep you ticket free even at those speeds.
11*43+456^2
Hopefully won't be.
My dept. has rep from Hurst come by yearly to let us know what ways of killing us the auto companies have come up with next. Then we spend an evening tearing up cars. Not a bad night, it's normally pretty fun.
But the key is that we try to stay very aware of what's in the newest cars, and even sometimes a few of us will go a dealership to look at the new models, and take a look at the key things we need to keep an eye out for.
While the new technologies have made a greater chance of surviving the wreck, they've also increased the time that you're likely to be stuck in the car if we need to go cutting.
My favorite so far are the polycarbonate windows. They don't shatter in an accident, and they compress and store energy, waiting like a coiled spring. Hit them with a sledge hammer and they won't break. But start cutting into the roof, and they try to launch the roof off the car if they've been compressed and bent.
Also fun is the poor guy who rolls his bmw 745, has some minor dents/scratches in the roof, but can't get it out (doors won't unlock). However, we can't shatter out the windows, so we have to tear off the doors. Instead of just replacing the glass, the car is likely totaled by insurance.
1 - the path through the body is the key - if it passes through the heart at some level (low mA) you can/will/do get V-fib (VF)
2 - you must have voltage to get to the heart - less than 80 will seldom do it, but this depends on skin moisture and pH, how much water you have on board, do you drink Gatorade or just sweat alot...
3 - high-current electrocutions do kill people, because you don't get this high current instantly or constantly - imagine 2 A, followed by a trailing off to 80 mA - gotcha.
4 - Gauss plays some role - if your skin carries the current because it is wet or otherwise highly ocnductive, you may feel a shock at a lower voltage, but no cardiac issues (except fright).
5 - Cars are running on DC, which requires that you basically make contact with two dissimilarly polarized surfaces - it cannot ground to the earth - old electronics technicians only use one hand for this reason.
Stick a 9-volt on your tongue and tell us about it.
Faith is the very antithesis of reason, injudiciousness a critical component of spiritual devotion. Jon Krakauer
No no no,
this thread is going into miss-information fast
The system developed for the Prius was made by a 3rd party company which is partialy owned by toyota. Toyota took their works and continued the development of their system. Ford worked with the same 3rd party company, but largly designed their system theirself (ford by far leads in R&D on hybrids, just haven't put anything out till late summer). They did make a deal with toyota over some of the controls, mainly to avoid patent violations, but it does not share tech, just look at the 2 systems in person and it's obvious, or talk to someone who has worked on one them.
Honda does not use the same type of system at all. The use a integrated flywheel, motor, altenator. It's sandwiched between the engine and tranny. Its a crappy lame hybrid, same thing as GM is putting out in their trucks as an option. Most would not call it a hybrid, at most call it a mild hybrid. But Hondas marketing is at work.
The CVTs in the vehicles are differant. Ford and toyota get their cvt via the planetary gearset used for the powersplite between the engine, generator, motor/wheels. There is no tranny to speed of, just the powersplit unit. The insight and civic use a normal transmission or you can get it with a cvt that is of a complicated deal using cones and belts and what not. They are very differant.
Also there is no patent infringments with using the planetary for the powersplit since this idea is as old as gearing it'self.
Also though you said nothing, i doubt ovonic has any claim over nickel metal hydrid batteries. Since that tech has been around for long anough for any patents to expire, plus their is so many ways to make such batteries you could get around them, and ovonic is more active with lithium ion batteries. And the Ford escape hybrid uses Sanyo batteries if anyone cares.
My other negative reaction is, if I'm in the middle of nowhere and it dies, or I go to start it and it just doesn't work... then what? I can do a lot to get a conventional vehicle back on the road. With this thing it either works or you are done.
1. Roadside assistances comes standard during the warranty period.
2. It's a Toyota - when's the last time you had a Toyota break down? Any Toyota I've ever had or been involved with has just ran and ran and ran....
$ man woman *
-bash:
"batterys have to be 200 degrees to operate . . ."
What planet are you from?
NiMh cells are, in fact, kept COOLED to room temperature by means of a blower system.
Perhaps you are referring to that mythical "hydrogen fuel cell" thinggie that Detroit has squandered several billion in taxpayer's money just to tell us "in 20 years"?
T_O_M
The chance of irregular heartbeat following electrocution is something like double the norm for 72 hours post shock for common voltage/amp combinations. Until the HMOs got involved, it was not uncommon to be hospitalized for 1-3 days following even relatively minor (110 VAC) experiences when the victim/patient had symptoms like muscle contracture.
Like almost everything doctors do, it was based on (bad) experiences "he's fine, send him home." D'oh.
Faith is the very antithesis of reason, injudiciousness a critical component of spiritual devotion. Jon Krakauer
Racing cars have a standard placed cut off for the motor/fuel line inside the drivers door for rescuers, why not something like that for the hybrids?
There is. In my Prius, it's in the trunk on the left side of the battery pack. Pull out the orange disconnect plug. Upon loss of the 12 volt system, the high voltage circuit breaker in the trunk opens so simply cutting the small 12 volt battery cable will do the trick.
In the Honda Insite, the disconnect switch is in the back under a small square cover.
The truth shall set you free!
First off, I am an engineer and have studied the Prius quite a bit. High Voltage safety on production hybrid/electric vehicles is great. First off, 500 volts is absolutely wrong, the battery pack in the Prius runs at a hair over 200 volts. Second, no high voltage wiring is run in the doors or roof or anywhere besides under the undercarriage of the vehicle between the packs and the inverters. Third, there are main cutoff relays located inside the battery boxes that are hooked to an inertial switch that will disable any voltage coming from the boxes if an impact is detected. This is the same switch that kills your fuel pump if you get into a wreck. Fourth, the high voltage pack is completely isolated from the vehicle's chassis, unlike the 12-volt system which has one side attached to the frame. What this means is should through a near-impossible combination of events one of the leads get cut into the frame and become energized, it would be impossible for you to complete a circuit and get shocked because the other end is still isolated. (houshold wiring can shock you because your feet complete a circuit through the earth, but this isn't the case in a vehicle!) If both ends of the pack were to connect to the frame, the fuse built into the pack would blow from the short-circuit. The only real danger is from a ruptured battery pack itself, but that's pretty easy to spot. Nothing to see here, move along.
Anyway, the Yaris wouldn't start when it rained, so I sold it. So much for Toyota build quality.
Do a google search on "echo suppressors for POTS" or maybe "how a DSL modem works". Also search for topics like this one.
Actually, no, that's not true, the "55 by itself" thing.
The way the Prius works, you actually have two motor/generators. MG1, the small motor, which starts the engine and, at low speeds, acts as a generator, and MG2, the large motor, which is on the final drivetrain and gives you that big torque when you start up.
MG1 serves another function: it balances the power between the ICE and MG2/wheels, providing the effect of a CVT, even though the Prius has fixed gearing. So when you're going slow, MG1 acts as a generator, dragging on the "power-split device" and providing the effect of a low gear (it's running against the movement of the ICE).
But above about 60mph, MG1 has to, instead, push in the direction of the ICE motion, acting as a motor rather than a generator, to provide the effect of a high gear. During this, MG2 is engaged as a generator to provide MG1 the power needed to do this. So there's no charging, period. But also, no dependency on the batteries: you can and do get to the top speed of 99mph (for the 2001-2003 car) regardless of the battery charge.
-Dave Haynie