Anyone have a copy of that article? They used a lawn mower engine to run an alternator to recharge batteries running an electric motor. I'm interested in whether that could be duplicated using something like a Geo Metro/Suzuki Swift or something else...
stroker wrote: They used a lawn mower engine to run an alternator to recharge batteries running an electric motor.
I'm calling BS on this, it may run, but I'm betting that its a POS that can't get out of it's own way, and may catch fire at any moment.
HappyAndy wrote: I'm calling BS on this, it may run, but I'm betting that its a POS that can't get out of it's own way, and may catch fire at any moment.
Well of course it's BS. You need a certain amount of HP to move a car, regardless of where it's coming from. If the generator engine they are using makes 20 hp, that's how much the car will have to work with average, with the batteries taking care of spikes. 20 hp sustained is enough to move the car at something like 40 mph depending on aero and tires. The batteries probably store enough energy to get you there, but to think that a 20 hp generator is enough power to drive it just like any gas engine car is silly.
DIY Electric Geo Metro with 30 year newer info/technology.
We did a calculation in college for the required horsepower of a Ford Contour to go 35 mph on a flat road and it came out around 12 hp, IIRC.
I seem to remember something from grade 11 physics that says every time energy changes state, there is a loss.
You'd be more efficient pouring the gas in the generator into the fuel tank of a car.
Shawn
Trans_Maro wrote:stroker wrote: They used a lawn mower engine to run an alternator to recharge batteries running an electric motor.
It's not dumb, this is the same concept behind the Chevy Volt, and every diesel-electric locomotive. It's probably not the best setup for a car because of the frequent changes in speed and lack of need for monstrous torque, but it can work.
Trans_Maro wrote: I seem to remember something from grade 11 physics that says every time energy changes state, there is a loss. You'd be more efficient pouring the gas in the generator into the fuel tank of a car. Shawn
Do you think it would still be more efficient in city traffic, with the engine idling for long periods of time?
In reply to GameboyRMH:
Why would you idle the engine for long periods of time. Shut it off.
I am with Trans-Maro on this one. I am always amazed when complication is added to the propulsion of a vehicle and somehow the result is supposedly more efficient.
Rob R.
GameboyRMH wrote:Trans_Maro wrote:It's not dumb, this is the same concept behind the Chevy Volt, and every diesel-electric locomotive. It's probably not the best setup for a car because of the frequent changes in speed and lack of need for monstrous torque, but it can work.stroker wrote: They used a lawn mower engine to run an alternator to recharge batteries running an electric motor.
It's dumb because you need a lot more power than that to make enough electrical power to actually move the car in a sustained way. You can't make a 20 hp lawn mower engine create 100 hp worth of power to the wheels unless you have enough batteries to make in an EV. If the thing is only good for 30 mph on the generator once those batteries are exhausted, it's pretty useless.
While 20hp is probably low for that it needs. The original electric Opel GT was probably a good choice. It was lightweight with a slippery body that did not need a lot of HP to get it moving or up to speed. The opel 1 litre engine only produced a paltry 48 hp, so it was only down by half. the GT probably only needed 20hp to maintain it's speed and the batteries were for acceleration. Much like the original Honda Insight
One thing people forget about engines, smaller engines run best at a steady speed and fully loaded. A generator does exactly that, it runs at the same RPM and stays fully loaded at all times. it is probably a very doable project if you take all aspects of it into consideration.
I know from my playing with the torque app on my phone.. at 60mph, I am only at 9% throttle with a minimal load to run my Land rover.. how much power does it take to move a car at a little more than a third of the weight that is a lot more aerodynamic?
I can cruise at 65+ mph in a Land Rover that has stupendous amounts of rolling resistance and the aerodynamics of the barn it came in. The vehicle has 38 hp at the wheels. The actual amount of power needed to propel a vehicle is usually overstated pretty badly.
Maybe the technology could be incorporated into a go3wheeler...
That Opel GT was in Mother Earth News published in 1979 folks. It's not something new.
For the time it was certainly better than me Trimuter or CitiCar.
http://www.motherearthnews.com/green-transportation/electric-car-conversion-zmaz79jazraw.aspx#axzz345yl0CRw
Well darn. 
I've had a similar idea in my head for a while and now I see it's been done. Although battery tech has improved it just doesn't cut it for full use............yet. I'm sure it will get there eventually but I thought that a generator supplying power to an electric motor could do the job. Wouldn't count miles-per-gallon but gallons-per-time like hours or something. Would think generator tech is closer to practicle use than battery tech.
A local college has done some impressive and bizarre experiments in hybrid cars. Veggie oil powered turbine generators, 4 separate wheel motors, capacitor recharging on the fly, all sorts of aero and efficiency modifications. Many didn't progress beyond a foot long model but even those were amazing!
My favorite has a 20 horse diesel with a 60 horse electric motor. Has all the bells and whistles that is everything from a sub 12 horse cruise at 65 mph to all of both motors for acceleration to all electric puttering around. Fun part is that the guy who drives it has a solar shed with batteries at home that powers his house and charges batteries with another at school.
Last time I saw it they had finished carving off all the unneeded steel and replacing with carbon fiber, lexan windows. I need to check back as they had just been informed that they were getting Lithium Ion batteries and had plans for a bank of roof mounted solar cells.
A little research will show you that the Opel is very crude...that is why I like it very much!
Bruce
Every energy conversion has a loss associated with it. Ideally you would want your ICE to be able to power the wheels as directly as possible when power requirements were at or below what it could deliver. This is part of why all us science-minded nerds sneered a little bit when GM got defensive about the ICE being able to propel the Volt when that was, in fact, a good thing.
My take on this idea (that i will probably never do but enjoy thinking about) is take an air cooled VW body and mount both an electric motor and a small ICE powerful enough to maintain highway speed by itself (like a 250cc bike motor) on a chain or belt drive with the ICE having an overrunning clutch. That way you have full electric when wanted, ICE steady-state efficiency and range, and ICE+electric WOT power.
Pretty easy to get HP vs speed with coast down testing.
Just need a level stretch of road, and accurate vehicle weight.
ISTR that the G-Force units would compute this for you, but it's pretty simple math,
and the iPhone dyno apps will certainly do it.
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