electric_ride

Can anyone help me with the circuit I would need to have to make this work ? I am not so worried about overcharging the batteries because a 10k generator can not produce enough current to overcharge the batteries ,but it will increase my range by 75 % . Also if Im using less than half the gas that a Prius uses then I can not see how IM a bigger polluter and I am certainly polluting less than a fully gas powered vehicle.Plus if I run out of gas ,who cares I can still go a long way a Prius can go two miles LOL.Is there anyone that can help with this?

__________________
Crusin' Usin' Electric

bryan1

Hiya Electric Ride,
Eh mate checkout this link http://www.thebackshed.com/Windmill/...p?TID=691&PN=1

Trev has converted a hilux ute over to electric and I'm sure you'll get some good pointers off his diary.

Hope this helps

Cheers Bryan

__________________
" The only way to avoid human error is to avoid the use of humans"

audioguru

Modern hybrid cars use their electric motor as a generator when the brakes are on.
They turn off their engine when it is not needed.

__________________
Uncle $crooge

Oznog

Actually EVs have BRUTAL low-end torque if they have quality (expensive) batts and components. They can totally destroy up a stock rear end. Stock cars converted to EVs by amateurs who know their stuff have broken into the 10's for the quarter mile.

Well got some tough numbers for you.
It's REALLY hard for a generator to compete with a car engine for efficiency. Went through this awhile ago. Car engines these days are hella well tuned. Generators have the unique advantage of running at constant rpm and load, but that was only a big deal when cars were running on carbs which can't respond with mathematical precision like an EFI system. There really aren't many small generators designed for great efficiency, they're designed to be big and cheap and nobody cares.

Bottom line is we ran the numbers, calculated generator head losses, controller losses, and motor losses, and it **might** be slightly better (maybe 10%-15% more mpg) than the car's engine, but more likely less, and certainly can't double your mpg or anything. For one, we didn't take into account that even a 10KW generator is HUGE, heavy, and might need to be pulled on a trailer. Now that's assuming the power won't be stored in the batt. Storing in a lead-acid batt and taking it back out can lose 30% of the energy as "cycle loss" so at that point the budget to compete with the original engine is definitely broken.

And I've also considered top of the line turbines. They may come with substantially better efficiency, but we're talking in the 10%-30% range. In fact that's where the "best case" of minor mpg improvements comes from.

Plus a gen lacks any oxygen sensors, EFI, and catalytic converter. It can produce tens, even 100x the pollution per mile of a modern car! It's probably illegal and certainly not "green". A common 10KW gen is phenomenally noisy and smelly too, I mean it'll get you noticed and not in a good way.

Suggest you go here right away:
http://lists.sjsu.edu/mailman/listinfo/ev

Search the archives to catch up then do some talking. These guys know exactly what backyard EV tech can and can't do. The generator has come up and the numbers just keep pointing to it not being a solution that meets "green" or even fuel-efficiency goals.

Sorry but the "60 mpg Hummer" guy (Jonathan Goodwin):
http://www.fastcompany.com/magazine/...d-messiah.html

His claims don't hold up to scrutiny. He made a nice EV that is a pretty good example of what amateurs can do. He doesn't present any reasons to justify how he's gonna make a 100mpg 1960 Lincoln Continental- he just says it's a goal. A lot of his other points are totally unrealistic by a long shot but it's sort of a long story why.

__________________
I thought what I'd do was I'd pretend I was one of those deaf-mutes.

electric_ride

Hey Oznog , yeah I have been looking at several things and know I will have losses , I do not plan to using gas though . I do not plan to use the gen all the time either for regular commutes it would just be dead weight , my interest is if I would like to do a few hundred mile trip .If it proves out to be a worthless device on the vehicle the upside would be in case of a power outage I have a way to power the house and garage up.Thanks for the links I will check them out.

__________________
Crusin' Usin' Electric

Oznog

Well, people have argued the "range exender" generator. You can argue whether the emissions and expense justify this because you'd be able to use the EV far more often.

The facts remain that it can't make wheel power from gas, biodiesel, or any combustible fuel much better than ICE and probably worse. Its emissions will be frightening by modern car standards, it's gonna be huge, loud, and smelly unless you find something real special in generators. Get a realistic figure of how many KW it takes to make the vehicle cruise at a particular speed (it's quite a lot!). These problems are hard to get around because the bottom line is it's not likely to have mpg gains over putting the same gas or diesel in the original engine.

You can tap its exhaust into the car's original exhaust system to use the muffler but these gennies radiate a lot of noise off the engine itself. Contrary to the "superhummer guy", vegetable oil biodiesel does not come with any inherent difference in the noise level.

A few guys actually sawed a front wheel drive car in half, welded on a tow bar, ran a throttle cable out of it, and actually used it as a gas/diesel "pusher trailer" to transport the EV over long distances. Personally, holy crap, I can see the dynamics of that are so wrong- in a turn, its pushing force is trying to make the vehicle's rear wheels skid sideways and jackknife you. Not something you wanna deal with in rainy weather. So far haven't heard of any accidents but it's only been done a few times.

__________________
I thought what I'd do was I'd pretend I was one of those deaf-mutes.

audioguru

What happens when you drive a fully loaded Prius up a mountain then the battery runs out? Is its tiny engine powerful enough to push the car up in 1st gear? Then won't it also run out of gas after a few days and only halfway up?

__________________
Uncle $crooge

Oznog

Yeah, the Prius engine will get it up there once the batt's done, just slowly.
Generators on the size you're used to seeing at Harbor Freight Tools and all aren't anywhere near big enough to even keep it going down the road, well maybe at 15 or 20 mph but nothing realistic.

Keep in mind that the Prius' remarkable mpg isn't even a direct result of being a "hybrid". The thing is it uses an "Atkinson Cycle" 4-stroke, never before seen in a car engine. Atkinsons' is much more efficient but has a poor peak power output for its size and would not be considered driveable in a normal car. The battery booster makes it driveable by lending an impressive peak power. Just as important, the Prius has one of the lowest coefficients of drag ever seen in a car, experimental or otherwise. It's quite light. The drive train and stock tires makes a low rolling resistance. Half the drag of a big, boxy car already gets you twice the highway mpg right off the top without doing any hybrid/engine tricks.

__________________
I thought what I'd do was I'd pretend I was one of those deaf-mutes.

Helder Ferreira

Prius has about the same power as a normal ICE. The difference, since it has 2 electric motor/generators, if it runs out of battery wich is impossible (the computer NEVER let the battery go below 40% of the charge). The system finds the correct combination of RPM ( usually at the peak RPM/Torque curve) of the ICE. At this speed the MG1 generates enough power to feed the MG2 to control the speed of the car. In a normal car, since you have a fixed ratio between the ICE rpm and the vehicle speed, you have to go in low gear all the time. Since the Prius has a CVT it will pick up or loose speed depending on the load condition. The engine will turn at a constant "high revs". Another fact about the battery. The computer never charges the battery abouve the 80% limit. This way the battery should last at least the 8 years of the warenty.

mneary

So the CVT can always keeps the ICE at maximum power or efficiency? Clever.

I've had more than a few ICE cars where, in 4th gear up a mountain I would accelerate nicely. But I would be approaching maximum safe RPM. Then I would shift to 5th and slow down due to lack of torque. I guess the CVT could give me 4.375th gear or whatever is necessary.

Helder Ferreira

CVT stands for continuous variable transmission. You can find a simulator here: http://homepage.mac.com/inachan/prius/planet_e.html

Oznog

Well this is particularly important for the Prius' Atkinson-cycle engine:
http://www.keveney.com/Atkinson.html

A significant loss in traditional engines is the fact that on the intake, if the throttle's not 100% open it reduces the amount of air being taken in by creating a partial vacuum in the cylinder on the intake stroke. That wastes power to draw the piston back against the vac it creates. Atkinson cycle instead just changes the length of the intake/compression stroke so it only takes in the air it actually needs thus no vacuum. But this is difficult to throttle (actually Atkinson shouldn't have a "throttle" at all) and I believe it generally has a funky power band too. The CVT makes it usable by allowing it to sit at one RPM and the batt makes up for its lack of peak power.

__________________
I thought what I'd do was I'd pretend I was one of those deaf-mutes.