Hi
I just finished watching a review of the new mercedes smart car electric edition. I have a gas powered smart car on order so i am a big fan of this tiny car.
anyone wanting to watch the 10 minute review can go to youtube and search on “smart car ED” - it was on fifth gear, a british car show.
The question that i have is common to Evs that i have not found an answer to. At the end of the video, the car runs out of juice. The presenter then pulls out a gas powered generator, starts it up, plugs it in, and drives off the car. Is this possible? If it is, cant we just create EVs and add a small gas generator for situations when the car is out of juice?
[QUOTE=britboy;2021]Hi
The question that i have is common to Evs that i have not found an answer to. At the end of the video, the car runs out of juice. The presenter then pulls out a gas powered generator, starts it up, plugs it in, and drives off the car. Is this possible? If it is, cant we just create EVs and add a small gas generator for situations when the car is out of juice?[/QUOTE]
Yes, that is possible, and it has been done (mostly by hobbyists). However, the idea of having an electric only vehicle is to NOT use any gasoline at all, thus saving you money while protecting the environment.
I have a neighborhood electric vehicle (NEV) and a vehicle with an internal combustion engine (ICE). The NEV has a range of about 30 miles and a max speed of 35 MPH. I use it for all of my local errands (going to the grocery store, mall, post office, school, etc.) and use my ICE vehicle for trips and freeway driving.
At the moment there are no affordable EVs that have long range and are highway speed capable. However, that is going to change in two or three years. Several companies are in the process of developing new batteries, such as ultracapacitance, that will make the range go up significantly. They will be much lighter, allowing for MORE batteries - thus providing freeway speed capability. Watch for the announcements that will be coming.
using a small generator to power an electric motor would be 20x more efficent than it currently is to power the wheels as it is more consistant than traditional motors powering the wheels, and size of the motor usually… but a small generator could produce better power ratios and use less gas… i’m surprised they havn’t done this already…
I think an elevtric car with a range generator is not only a good idea, but probably the only way americans will buy it. Having a range extender means that people will not be put off by a limitied range car.
We already know that electric engines are faster (even torque) more effecient, and will require much less maintenance since there are not as many moving parts. The range extended would rarely be used but means there would be no range limitations on the car.
This is not about being green it is about being realistic. People will choose thier pocket book over doing the right thing environmentally every time. Createing a cost effective efficient vehicle is the first step to eliminating the ICE
I’m not sure how you calculated that using a small generator to power an electric motor would be 20 times more efficient. If you have a 5 hp generator running an electric motor, you still have just 5 hp. If anything it’s LESS efficient, because you still have the inherent heat loss of the IC engine, plus additional losses when converting to electricity. It’s those silly laws of thermodynamics.
Take, for example the Saturn that NewDawn converted to electric. He used a 144V battery pack. Say at full acceleration the car draws 200 amps. That’s 28,800 watts. Even without conversion and heat losses, you’re looking at a 30 KW generator. More realistically, probably a 40 KW generator. That takes about a 50-60 hp IC engine to run it. Add some regen and batteries and maybe you could reduce the size of the required IC engine. But, maybe you want a little more performance. So, you increase the voltage and the IC engine size and what do you have? A Toyota Prius.
[QUOTE=rjstractor;2209]I’m not sure how you calculated that using a small generator to power an electric motor would be 20 times more efficient. If you have a 5 hp generator running an electric motor, you still have just 5 hp. If anything it’s LESS efficient, because you still have the inherent heat loss of the IC engine, plus additional losses when converting to electricity. It’s those silly laws of thermodynamics.
Take, for example the Saturn that NewDawn converted to electric. He used a 144V battery pack. Say at full acceleration the car draws 200 amps. That’s 28,800 watts. Even without conversion and heat losses, you’re looking at a 30 KW generator. More realistically, probably a 40 KW generator. That takes about a 50-60 hp IC engine to run it. Add some regen and batteries and maybe you could reduce the size of the required IC engine. But, maybe you want a little more performance. So, you increase the voltage and the IC engine size and what do you have? A Toyota Prius.[/QUOTE]
sorry for being exagerative… but i mean in terms of recharging the car/extending the range. if you have to drive cross state. its much better to have a generator on board with a small 1-2 gallon fuel tank to extend your range by up to 100’s of miles?
I think the question is about being realistic. Americans will not buy an electric car with a limited range. By limited range i mean a car that cannot be refulled on the road in under 5 mins. Even if the will was there, oil or car makers would put out negative adds to destroy these types of cars.
A generator is a good bridge until capacitor technology allows comparative use to an ICE to be possible.
My question is if it is so easy to do why hasnt it? since electric cars can be made that do 30 miles, and most people drive less than this, what is stopping it happen?
One of the drawbacks to a generator is that they don’t have the same pollution controls as an ICE. While you’re not running it all the time, when you do I believe it is polluting more than an ICE would be doing.
Combining a ICE with an electric motor in a vehicle is popularly called a hybrid. The Toyota Prius hybrid if purchased in Europe is a true EV (sometimes). It can travel 2-3 miles before the engine starts. In the USA this feature is not available for unknown reasons. The Honda Civic hybrid can not be run in all electric mode at all. Toyota limits the range in EV mode to prevent the batteries from being deep discharged thus extending their life.
Other car companies are experimenting with hybrid cars that have a greater range in EV mode. One EV conversion kit company is offering hybrid interface units to their kit to allow connecting the battery pack to a variety of generators. The idea being that the generator can extend the range and recharge the batteries even when the vehicle is parked. Also the generator can run at its most efficient and fuel saving RPM 100% of the time.
As for Americans not buying short range vehicles, I for one am willing to buy a car with a 40 mile range. That’s 5 times what I need for my daily commute and is enough range to visit my furthest friend’s house without needing a recharge.
The reason for not using a small generator to recharge an EV is that those small generators by nature are horribly inefficient. Yes they use just a small amount of gas, but they also use a small amount of gas to produce a VERY small amount of power. This is why we don’t use those small generators to power our houses. A huge generator at a powerplant is very efficient (relative to a small generator) in terms of fuel consumed for amount of electrical energy output. This is called economy of scale. A better idea would be to have electrical outlets for EV recharging. At your job, at the grocery store, at the mall, even at the ‘gas station’. Charge people for the power, set it up like a vending machine, put in a dollar and get 6 kWh of electricity.
Another thing people don’t seem to understand is that batteries require time to recharge. I have read a lot on this forum about ‘fast charging’ and different schemes for doing so, and certain batteries recover faster than other types, but generally, if you discharge a battery, the EV charging station should have a magazine rack, cuz you will be there a while.
