Electric Power Car NO BATTERY NEEDED!!

[KLP]

I have an idea to build an electric power vehicle that runs off of a portable generator. I will be driving 60 miles per day round trip to/from work. My thoughts are to use a mini truck so the gen can be mounted in the rear. The mini truck can be lightened up considerable by removing the rear bed among many other things. I am thinking of using some sort of AC electric motor probably a 220 volt? And mount it to the transmission to hopefully get more speed for highway. I have a 5500 watt gen that has a 220 output. I am wondering if the 5500 watt gen would be enough to power an electric motor large enough to run a car @ 60 mph down the highway? Does anyone have any knowlegde if this will work and how big of a gen I will need?

[waddie]

Sounds really inefficient, but good luck to you.

[GasSavers_landon]

5500 watts is about 7.4 horsepower assuming no losses. I'm not sure how much power you need, but you don't have it.

[JanGeo]

If you want to run any kind of safe speed think 55,000 watts at a minimum since the electric motor doesn't develop a lot of Horse Power at low rpms you may need even more power. The generator is not going to operate any more efficiently than a bigger motor in the vehicle already. You are trying to move too much vehicle and that can't be done efficiently unless you make it more efficient at converting gasoline to mechanical energy. Even with a small bank of powerful output Batteries and the generator you still are limited to the gas motor in the generator and the size of the vehicle.

[alexthedoobieman]

Originally Posted by JanGeo

If you want to run any kind of safe speed think 55,000 watts at a minimum since the electric motor doesn't develop a lot of Horse Power at low rpms you may need even more power. The generator is not going to operate any more efficiently than a bigger motor in the vehicle already. You are trying to move too much vehicle and that can't be done efficiently unless you make it more efficient at converting gasoline to mechanical energy. Even with a small bank of powerful output Batteries and the generator you still are limited to the gas motor in the generator and the size of the vehicle.

It is possible. Diesel Electric locomotives have successfully used this technology for decades. The rational is that tremendous loads can be moved from a dead stop. The drive wheels are relatively small compared to vintage steam locomotives so no transmission is actually needed. True we are talking about LOAD MOVING and electric motors put out high torque at low speeds. For the pickup truck, you do need probably 2000 pounds of batteries (48 batteries for starting draw of 80 amps each for 48 hp) Then the generator could charge the batteries plus regen braking could also help charge batteries. Without the generator, you could run the truck for about 120 minutes @ 25 amp draw for each battery which would be approx 12 hp total just to drive down a level road. Probably get you 60 miles tops. So, back to the gas electric model just think about the Prius hybrid or locomotives and try an engineer your vehicle around that concept. I'll concede that losses are significant but put your thinking caps on.

[KU40]

Originally Posted by alexthedoobieman

It is possible. Diesel Electric locomotives have successfully used this technology for decades. The rational is that tremendous loads can be moved from a dead stop. The drive wheels are relatively small compared to vintage steam locomotives so no transmission is actually needed.

I think you have this mixed up. I don't think the size of the drive wheels has anything to do with not needing a transmission. Whether you have big wheels that need a transmission for lower gears or small wheels that need a transmission for going faster, you'd still need one. The reason diesel locomotives don't need a transmission is just because it uses electric motors. The big advantages to not having a transmission are weight saving, fewer moving parts, and less maintenance on not only the transmission, but the diesel motor itself. A motor that needs to only operate at a certain RPM for sustained periods lasts much longer than one that constantly changes RPMs (think highway miles vs. in-town miles in a car and their effect on the longevity and wear on the motor). Other advantages include electric motors just being more efficient than a transmission, having each axle powered by its own electric motor (instead of having them all bolted together like steam engines), and each electric motored axle is independently controlled, meaning that if one slips power can be adjusted. Wheel slip is one of the biggest problems a locomotive can have.

[GasSavers_RoadWarrior]

at 100% efficiency, that would get you to about 55mph in a 1500lb vehicle with a low Cd and RR.

In reality, it's barely gonna be safe in city traffic. 7HP is about what they put in electric motorbikes.

[theholycow]

Burning gasoline to make rotational motion, converting that to electricity, and then converting that electricity back to rotational motion is very lossy. Such a design would not offset the losses by the increased efficiency of being able to run the gas engine at its optimum RPM/load combination.

Electric cars gain effiicency from storing power in batteries and recovering power with regenerative braking. The Prius combines those gains with a specifically-designed gas engine + generator combination, and of course the low drag (aero, RR, etc) design.

You're not going to beat the big budget R&D departments of major manufacturers by throwing a generator on a rusty Mitsubishi Mighty Max. Don't get me wrong, it's not impossible for a grassroots effort to beat big money R&D; it's pretty common, actually. It's just not common in this particular sector, and especially unrealistic the way you described.

[kamesama980]

not to mention the cost of implementing a variable speed AC motor reliably as you need here.

I'll tell ya first hand, you can't lighten a mini-truck much (unless it's a newer one with lots of interior) the bed ain't much. 2 average size guys can lift a full-size short-bed pickup bed without much trouble. I'd say 150 lbs tops. a minitruck bed is maybe 120 if even...

[GasSavers_Ryland]

My 1,400 pound electric car draws 4,000 to 6,000 watts while going 35mph down a flat road and 22,000 watts for a few seconds while starting from a dead stop, unless you over size your generator to the point that it uses more gas then you could imagine then you are going to need a decent size battery pack that can handle the possible 40,000+ watt draw you are going to need in a truck to get moving from a dead stop.