Alternator
I know about the laws of physics and energy can't be created, but do one building an electric vehicle is even considering an alternator. Even if they added an alternator that was only 80% efficient that could still increase the mile the vehicle could travel in one charge.
I am excited about the new technology, but this is just another way for the rich to get richer and the poor to stay poor. By not using alternators to increase the distance the vehicle can travel in one charge and also reduce the number of times it needs to be charged they are making another market and insuring more profits. All of the materials and labor to install the electrical outlets and infrastructure for the system is eliminating any decrease in emissions the electric vehicle might save.
Brad
One More Thing!
Brad;
I should not have told you to just forget about alternators... what I should have done is to explain how useful they might be. If you attached a wind mill by pulleys or gears at a 20 to 1 ratio, 100 RPM on the wind mill would translate to 2000 RPM on the alternator, which could in fact completely power a recharging station for one or two cars. Now this would leave the PBP recharging infrastructure out of the picture except for inter-city travel, but there will be plenty of days when there is not quite enough wind (that is what the wall current is for) or, even worse, the car owner forgets to plug in upon coming home. However, many people don't have anywhere that they can put up a 150 ft windmill tower (about the height where the wind aloft is present, even through the night) and can't plug in at home.
PBP could be the primary energy provider for people in these situations, apartment dwellers, homeowners in low-wind locations, and people who just don't want to bother with energy self-sufficiency.
Pete Aguilu - Green Fanatic!
Alternators - What are they?
Sorry sir,
I am a mechanic and I must explain to you what an alternator does. Just like an air conditioner compressor, the alternator is a parasitic device. It is used to power accessory equipment, and recharge the service battery (who's primary function is to start the gas engine, after system shut-down). The way it works is to directly draw some of the rotational energy from the internal combustion engine's crankshaft and convert it to alternating current at about 16-18 volts, which is then 'sliced off' by a rectifier to produce direct current at about 14 volts and somewhere over 20 ampres of current, driving most of the lights, bells and whistles, not to mention the ignition in a gas car and magnetic clutch that operates the AC, if you have that. There is also a regulator designed to limit the voltage to 14, even when the engine RPM could generate more, so that the battery is not damaged by overcharging.
So, rather than extending range, an alternator in any vehicle will actually reduce it's range by drawing off energy. See my forum topic on Modular Battery Design for more information and the solution that I recommend for handling accessories like the AC and the cabin heater.
I think you may have intended to talk about a recharging generator, like a biodiesel motor, small gas motor, hydrogen cell, or solar panels. These would in fact recharge the batteries somewhat, and indeed extend the range of the vehicle.
Pete Aguilu - Green Fanatic!
Another question
Thanks for your input, but I have another question about alternators. What if they were to install a Permenant Magnet Alternator. You can buy one online that produces 57 amps, 120v at 1,750 rpms or more powerful than that. Wouldn't an alternator with this capacity be able to recharge the car battery?
Also, let's say that even the PMA above would still have a negative production of electricity. Couldn't you install gears inbetween the electric engine and the PMA. Wouldn't that create more mechanical energy, that the PMA can use to produce electrical energy, than the electric motor needed?
Any information would be appreciated.
Thank you.
Brad
Charging a battery with an alternator
Brad;
I wish I could tell you that this would result in a net improvement of the power reserve of an electric car, but it just isn't true. The starter on gas autos is an electric motor and draws about 75 - 180 amps at 12 volts when cranking the car. If you had an older manual transmission and could put the car in first gear while running the starter, it would barely keep up with the top speed of first gear, in fact the car would barely move. Admittedly, the gas engine is also being cranked. If you disconnected that and allowed just the starter to push the crankshaft, I imagine you would have about 3/4 of the idle RPM (about 800-1200 rpm) at best. This would be about 15 mph or so. The point is that any electic motor which can push an EV at even 50 mph is going to be 10 times as strong and draw way more energy than a starter motor.
Now to clear things up completely, I must mention that any recharging accomplished by an alternator running on the main drive train would be at the sacrifice of at least the same energy taken from the power moving the vehicle forward (thus losing range for the same energy expended) Any gain in the charging would come directly from the speed lost. By driving more slowly and not using a parasitic accessory, the best range will be achieved because of lower drag and friction at lower speeds. another thing to remember: all these prototypes and experimental tests are run in nearly ideal conditions to get the best results possible. Actual driving conditions will nearly always result in somewhat lower performance. Once the benchmark of 180 mi (300km) range, at 55 mph maximum speed, on one charge is reached, then adverse conditions will be less of a factor in feasibility and price/performance/infrastructure/safety will become the limiting factors in deliviering EVs to all consumers. It seems that we are just about done with making the cars work. So what is next?
Pete Aguilu - Green Fanatic!