While driving this morning and watching a Prius pass me, I had an idle thought, but I'm not enough of a physicist to know whether it merits further study.
If one had an all electric vehicle, with a passel of batteries in the trunk and under the hood, and attached some sort of generator or dynamo to the running gear, why couldn't you generate electricity to recharge the batteries? I know that in theory it's impossible to create a perpetual motion machine, and that there has to be some loss of power when charging a battery, but (to the physics majors and Popular Science readers on the ng) what is the reason that this sort of thing wouldn't work?
Commercial Jetliners have fans that pop out on the plane when the plane loses electricity...it creates just enough electricity to run the pannels on the plane... i wonder even though it would be little electricity... how much could be created with fans in the vent in front... especially on the highway.
The problem is that the energy needed to turn the fan comes from the motion of the vehicle. Putting the fan on there would increase the resistance of the car going through the air, which would increase the amount of energy needed to propel the car.
Instead, it makes more sense to drive a generator or alternator directly off the engine.
I bet you could get a few kilowatts of such a generator.
"mack" wrote in news: snipped-for-privacy@corp.supernews.com:
Because... entropy always increases.
Using the electric motor's own motive force to recharge its own battery is akin to eating yourself in order to stay alive.
The effort needed to move the mass /and/ recharge the power source (battery) would deplete the power source faster than if you used the power only to move the mass instead of trying to move the mass and recharge its motive power source at the same time.
I think you pointed it out clearly: because no battery, motor or generator is 100% efficient you will always consume more power than the closed system can produce.
According to your logic, you wouldn't need a car. Hope on your bicycle, pedal it up to speed and coast for the rest of the trip. You don't need batteries, generators, electric motors or fuel.
In my opinion, the key for an all electric vehicle is the battery plus what is popular nowadays called *super* capacitors, that discharge current faster than a regular battery.
Given the chance, I still wouldn't buy an ALL electric car, like the Tesla. I like the idea of a plugin vehicle with a standby engine for long distance driving and battery charging. However that engine would NOT need to be sensitive to maintenance. I mean, when would you change the oil if the engine is almost never used.
Anyway, what I understand form the OP is, given a car have driven wheels in the front why not use the rear wheels to generate electricity. This would mean load for the engine but the car was designed to carry 5 people and cargo, if there was a sensor that detects the passengers cargo when only carrying 1 or 2 passengers, a clutch would engage and engage the generator such that it was just carrying the max load. Its just using the full potential of the engine to generate reserve (and not complete perpetual motion) charge. So its just making use of the wasted energy. But then again, does the revised EPA estimates consider 1 or 5 passengers?
If you are referring to Toyota's HSD as used on the Prius the only clutch is a permanently engaged one on the gas engine's output that I think is only there to prevent MG1 from overspeeding and exploding as a result should the engine for some oddball reason (like lack of oil) seize up while the car is moving at freeway speed. If you study the way the transaxle it made you will see that the only thing that ever shifts is the parking pawl/sprag. The wheels, MG1 (generator), MG2 (motor), and engine are directly connected to each other by the power split device which is nothing more than a simple planetary gear such as those in a conventional automatic transmission or on a smaller scale those in a cordless screwdriver/drill. With the engine off (not turning) MG2 will always turn at an RPM that is about 59x the speed in MPH and MG1 will turn backwards at an RPM of about 154x the speed in MPH.
Hybrids use the braking energy, that otherwise would be lost as heat, to generate electric power to be stored in the batteries. Any other attempts, such as charging the batteries while the vehicle is coasting in the highway, will end up using more energy than can be stored, given that no energy transforming system is 100% efficient.
How l> While driving this morning and watching a Prius pass me, I had an idle
You got it! I do not suffer fools gladly. All the original poster needs to do is think about the world around him and what happens after coasting down a hill on a bike. If he did that, he wouldn't have asked the question.
Good question. The answer is unknown since Toyota has not sold any replacement battery packs for reasons other than damage or defects.
At $2k plus a pop this
Toyota will accept all batteries from their hybrid systems for recycling through Toyota dealers.
The
I'm not sure if that is a question or a statement. There are no fuel "consumption" standards at this time, but if you mean fuel "economy" standards, then the hybrid system is a means of achieving better fuel economy, not the other way around. There are several ways to improve fuel economy, but every one has drawbacks that consumers may or may not be willing to tolerate. For example:
Hybrid drivetrain Pros: lower emissions, can have higher fuel economy. Cons: higher cost, more natural resources needed to manufacture, need to recycle/dispose of batteries
Smaller gasoline internal combustion (IC) engine Pros: lower emissions, can have higher fuel economy, generally lower cost to manufacture Cons: lower performance, noisier, not suitable for some uses such as towing
Diesel engine Pros: higher fuel economy, good torque Cons: higher cost to manufacture, different emissions, higher cost of diesel fuel offsets some fuel economy savings, less availability of diesel fuel, public perception of diesels as "dirty" technology.
Lightweight materials to make the vehicle Pros: weight savings means fuel savings Cons: much higher cost to manufacture
Smaller vehicles Pros: smaller vehicles mean weight savings, which mean fuel savings; fewer resources needed to manufacture Cons: Not as crashworthy as a larger vehicle; not suitable for many uses such as for large families, towing,etc., not as comfortable on long trips.
More gear ratios in transmissions or continuously variable transmissions Pros: improved fuel economy and performance Cons: cost more to manufacture
Plug-in-electric vehicles Pros: quieter, fewer trips to the gas station Cons: limited range, higher cost to manufacture, higher electricity generation costs
Fuel cells Pros: lower emissions Cons: no hydrogen distribution infrastructure
Alternative engines such as gas turbine all cost a lot more to manufacture at this time.
Improvements in fuel economy can also be achieved with the use of the vehicle's design and the use of technology, but they all have pros and cons. For example, a more aerodynamic body style may not be practical for a passenger van or pickup, and not everyone wants every car to look the same. Harder tires with less rolling resistance improve fuel economy but tend to ride more harshly and at this time, do not perform as well as conventional tires.
IMO, the engine start/stop technology used in hybrid vehicles and some conventionally powered IC vehicles have a lot of promise as long as people are willing to put up with the engine starting and stopping all the time.
A practical solution to improved fuel economy is already being undertaken by all of the automakers, using a combination of the technologies available today and continual minor improvements in those technologies.
Sorry, but I don't follow your alleged logic. What does coasting down a hill on a bike have to do with storing electrical energy by having a dynamo aboard an electric automobile? Nothing, in my view. Now try answering my initial question in a rational (and if possible, courteous) manner. Eh?
They're lasting long enough that it isn't yet an issue after many years.
I compare the battery in a Toyota hybrid to the conventional automatic transmission in other cars, with respect to worry about it from a replacement standpoint. Since the Toyota HSD doesn't have a complex automatic transmission, since it uses a very simple drive mechanism, there's nothing there to worry about.
So on the average car, it'll need major transmission work somewhere north of 100K miles. I imagine you'd need to replace the Toyota traction batteries similarly.
So the batteries aren't anything to worry about, any more than a conventional auto trans is something to worry about.
How is any battery being recycled to avoid pollution? Either the dealer does it, or--should you be replacing the battery pack yourself, which is not a huge deal--you can take it to anyplace that recycles batteries. Hell, Batteries Plus would probably take it.
Do you think that recycling the Toyota traction battery would be somehow different and more complex than recycling any other battery?
Do you know how many electric forklifts are out there in the world, facing the same problem? The infrastructure is well built up to recycle industrial batteries.
If you'd speak English, maybe I'd understand what that means.
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