# Building a series hybrid.



## jwalin (May 7, 2008)

Is a BEV with a genset on a range extending trailer a Series Hybrid? I jsut want to get the parameter straight as not to offend anyone.

My opinion, as expressed in the other thread, is to build a good, efficient BEV with the range you need for the large majority of your driving needs. Figure out how much power it takes to cruise it on a long trip, and size the genset to provide at least 90% of that steady state value, but not more than 100%. This will maximize the range, and lifetime of the battery.

You want the genset to operate most efficiently, regardless of fuel, and that means it needs to be running wide open all the time you use it. This means a single speed generator, with a small displacement, high RPM ICE, such as a motorcycle engine. Whether or not it is part of the vehicle permanently or on a trailer is just a question of what you define as a Series Hybrid.

Jeff


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## aeroscott (Jan 5, 2008)

jwalin said:


> Is a BEV with a genset on a range extending trailer a Series Hybrid? I jsut want to get the parameter straight as not to offend anyone.
> 
> My opinion, as expressed in the other thread, is to build a good, efficient BEV with the range you need for the large majority of your driving needs. Figure out how much power it takes to cruise it on a long trip, and size the genset to provide at least 90% of that steady state value, but not more than 100%. This will maximize the range, and lifetime of the battery
> You want the genset to operate most efficiently, regardless of fuel, and that means it needs to be running wide open all the time you use it. This means a single speed generator, with a small displacement, high RPM ICE, such as a motorcycle engine. Whether or not it is part of the vehicle permanently or on a trailer is just a question of what you define as a Series Hybrid.
> ...


look at the specific fuel consumption at differant rpms expresed as lbs/ hp hour like .35 at 2500 rpm and .40 at 3500 rpm


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## jwalin (May 7, 2008)

aeroscott said:


> look at the specific fuel consumption at differant rpms expresed as lbs/ hp hour like .35 at 2500 rpm and .40 at 3500 rpm


That depends on the design of the particular engine in question, it is not necessarily a function of RPM, but more of camshaft timing, fuel delivery, ignition timing, and compression ratio.

from wikipedia:

A typical cycle average value of BSFC for a gasoline engine is 322 g/(kW·h). This means the average efficiency of a gasoline engine is only 25%. A reciprocating engine achieves maximum efficiency when the intake air is unthrottled and the engine is running at its torque peak[_citation needed_]. Efficiency is lower at other operating conditions. For a gasoline engine, the most efficient BSFC is approximately 236 g/(kW·h) or an efficiency of 37%. As seen above, lower values of BSFC mean higher engine efficiency. Diesel engines are generally more efficient than gasoline engines and can have a BSFC as low as 155 g/(kW·h) (partly because of the higher calorific value for diesel fuel) and around 55% efficiency.

so it looks like a small diesel is what we would like to have due to the energy available in the fuel and the increased compression ratio. 

Jeff


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## heynow999 (Mar 2, 2008)

I agree that diesel is the way to go, but I have yet to see a small, light diesel generator. As many people have mentioned, WVO could then be used.

I have also seen propane powered generators, which I would imagine are very clean.


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## COMP (Jun 4, 2008)

heynow999 said:


> I agree that diesel is the way to go, but I have yet to see a small, light diesel generator. As many people have mentioned, WVO could then be used.
> 
> I have also seen propane powered generators, which I would imagine are very clean.


i'd like to find a small diesel gen. myself


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## ga2500ev (Apr 20, 2008)

Some tips on diesel generators:

http://www.backwoodshome.com/articles/thomsen43.html

Quite pricey.

ga2500ev


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## jwalin (May 7, 2008)

COMP said:


> i'd like to find a small diesel gen. myself


Well, here is the engine....this is the smallest I know of from Kubota. Just get a custom wound generator and mate it to it....117lbs + generator.

Jeff


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## ww321q (Mar 28, 2008)

This is the one I got 10 hp. 120 lbs. Cost $406 with shipping. Even came with a rebuild kit (rings,bearings,gaskets ) J.W. 
http://img.auctiva.com/imgdata/0/5/0/7/0/8/webimg/7843688_o.jpg


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## jwalin (May 7, 2008)

ww321q said:


> This is the one I got 10 hp. 120 lbs. Cost $406 with shipping. Even came with a rebuild kit (rings,bearings,gaskets ) J.W.
> http://img.auctiva.com/imgdata/0/5/0/7/0/8/webimg/7843688_o.jpg


what is the brand and is there a webpage with more details?

Jeff


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## ww321q (Mar 28, 2008)

jwalin said:


> what is the brand and is there a webpage with more details?
> 
> Jeff


EBAY ! just search 10hp diesel J.W.


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## COMP (Jun 4, 2008)

add link when found


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## Bowser330 (Jun 15, 2008)

Lets keep this topic going....so what is the idea of the setup...smaller battery pack with high charging-rate batteries plus a generator to deliver power to the battery pack....Motor is DC with excellent torque profile and gears to change through to get optimum speed...


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## jwalin (May 7, 2008)

Bowser330 said:


> Lets keep this topic going....so what is the idea of the setup...smaller battery pack with high charging-rate batteries plus a generator to deliver power to the battery pack....Motor is DC with excellent torque profile and gears to change through to get optimum speed...


My idea is to have a pure BEV with a small genset included to enable range extending for about 500 total hybrid miles. I would not want to reduce the size of the battery pack any less than 20-30 miles pure electric range. That way you cover most of your driving with just battery, which is more efficient and costs less, and have the reserve capability to travel for 500 or so miles on the genset when you need it. Ideally it would be a diesel genset, and could charge the batteries as the car is parked if no charging station is available.

Yes you lose range hauling a genset around with you all the time. My bet is it is not a big enough factor to really matter in the long run.

During hybrid operation, the genset would supply some amount (say 80-90%) of the current needed for steady state cruise at travelling speed (say 60-70mph). It would not supply enough to charge the batteries while driving. This way, the genset is operating at maximum designed power, which is the most efficient range. With such a low current draw out of the batteries, you are much closer to the C/20 hour rate of the battery, which will extend their life and allow you to maximize Peukert's effect to your advantage. For a typical passenger car this means a smaller ICE to carry than the typical parallel hybrid, but it does mean more batteries.

The hot setup would be an AC drive system to eliminate the transmission, and either NimH or Lithium batteries. But the same setup could be done with lead acid and DC systems if you wanted to, it would just weigh more and be less efficient. But it would still beat a Prius in MPG and efficiency.

Jeff


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## Bowser330 (Jun 15, 2008)

I completely agree with your setup and I want to build one just like it.

I would also prefer an AC systema nd Lithium Ions, however both are currently rediculously priced.

I want to do research on how to get a simiar system as AC Propulsion has made in China. I presume it could be made for atleast 5X as less..so 25,000 retail to 5000 retail...That makes it a lot more reasonable for the EV builder....

I think this guy is on the right track...
http://www.evalbum.com/1651

btw his battery pack units cost 300$ ea. so his batteries alone cost him 12K$...yikes...

back to the BEV, i do see a problem with how many kwh will be needed per hour to what a generator can provide per hour...A 10kw genset will give 10kw in one hour, by the time you have driven 1 hour though at highway speed you have used 20kwh...so that will effectively give you 50% more mileage if its running while you drive your 1 hour...so it will make your 70mile range (with lithium ions) go to 105 miles...pretty good....maybe i have the genset charging thing all wrong...what do you guys think?


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## Mad_Scientist (Jun 10, 2008)

What about emissions? Is one of these diesel generators that we're talking about as good on emissions as a modern car ICE? If not, how about a motorcycle engine? How are they on emissions?

This approach makes a lot of sense. However, it gets tempting to skimp on the batteries and settle for (lets say) a 25 mile range when you really want 40, since you have an efficient, low maintenance generator to depend on. Less batteries means smaller up front cost, less weight, and lower cost to replace the batteries. But if you do that, you end up running the generator a lot, and if it's emissions are worse than a car engine then you're going backwards, as far as emissions are concerned.


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## jwalin (May 7, 2008)

Bowser330 said:


> I want to do research on how to get a simiar system as AC Propulsion has made in China. I presume it could be made for atleast 5X as less..so 25,000 retail to 5000 retail...That makes it a lot more reasonable for the EV builder....


If you find it, by all means let everyone know! As I understand it, the limiting factor in AC drive systems is power electronics...they are quite a bit more complex that a DC controller. The IGBT's in the output are expensive, and they were hard to come by back when I was working in this field. Unless the Chinese have a bunch over there they are hiding, they won't be much cheaper than here in the US, because ours are made there anyway! The motor is simple, and can be made as cheaply or cheaper than a DC series motor.



Bowser330 said:


> A 10kw genset will give 10kw in one hour, by the time you have driven 1 hour though at highway speed you have used 20kwh...


746 watts is equal to 1HP, and most passenger cars use about 12 or 15 HP for steady state cruise. this works out to be about 9 or 11 kW, steady state. If you had a 144 V system, your current draw at 11kW is 11kW/144V=76A. If you had a 10kW genset putting out full rated power, it is putting out 69A. So you are drawing about 7 amps out of your battery cruising steady state. How long will your 144V battery pack go on a 7 amp draw?


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## jwalin (May 7, 2008)

Mad_Scientist said:


> What about emissions? Is one of these diesel generators that we're talking about as good on emissions as a modern car ICE? If not, how about a motorcycle engine? How are they on emissions?


Emissions depends on the diesel you choose. There are Kubota engines that have a tier 4 emissions rating, and they can be made clean. Or you can go cheap and use a diesel that runs dirty. So the answer depends on what you put in there....

But remember the trick to this theory is to use it as little as possible, and if you need a 40 mile range often, then don't design your car with a 25 mile range just to save money, because you won't! You will end up putting it in the tank and burning it.

jeff


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## Bowser330 (Jun 15, 2008)

jwalin said:


> 746 watts is equal to 1HP, and most passenger cars use about 12 or 15 HP for steady state cruise. this works out to be about 9 or 11 kW, steady state. If you had a 144 V system, your current draw at 11kW is 11kW/144V=76A. If you had a 10kW genset putting out full rated power, it is putting out 69A. So you are drawing about 7 amps out of your battery cruising steady state. How long will your 144V battery pack go on a 7 amp draw?


Thanks for the math thats exactly what I needed...but a few more questions too..

How do you know a 10kw genset it putting out 69A?

And I am not sure how to answer your final question, does the answer rely on the AHs of my battery pack? So if i have a 144V pack with 70AH does that mean the pack will power the motor in a steady state for 10 hours? with a draw of only 7 amps? (of course i understand WITH the genset on)


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## Thalass (Dec 28, 2007)

I too am hoping to build a series hybrid... eventually. Initially my car will be pure BEV, but being a ute I am hoping to be able to mount a genset in the tray area along with fuel tanks and such. A small trailer would be a good setup for a regular car, but not the most practical for quick trips offroad as I'll be planning to use the car. For longer trips sure, but they don't happen often. 


I would like to experiment with a stirling engine turning a generator, but in the short term I'll most likely end up with a small diesel instead.


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## weelliott (May 12, 2008)

I've done quite a bit of research on this. Apparently when you buy a 10KW genset they suggest it be powered by a larger motor than simply one putting out 10KW. 10KW is about 13.3 HP. However, they suggest a 20HP motor. So I'd think that a 10 horse Kubota could only really power a 5KW genset. 

So looking at a ten horse engine We could get 5KW out. This 5000 watts would give us say 50 amps on a 100 volt system. Or if you were running a 144 volt system it would only yield about 35 amps. I think that 35 amps in most cars is only enough for constant speed driving at slow speeds you might experience in residentail areas. You'd need a bit more power to hit the 90% goal proposed earlier, which I think is a good goal. I can see maybe lowering our expectations to an 80% goal, but even with that, the 10HP engine won't quite hit the mark.

There is a little company in Mississippi called wiseman engines. They hold the patent on the wiseman crank, which is a really ingenious little design for a crank. The last time I talked to them was in 2006 and tehy were working on a diesel engine then. they were designing a compact 10 HP industrial motor to be used for pumping water for irrigation and other radom remote location jobs. I think that if those are compact enough, or if they wre to modify the engine to be a two clyinder(which is easy for them to do.) they could supply a great little motor to the EV series hybrid community. 

Unfortunately I don't konw how their progress is on that engine. The last time I had talked to them they were still in the process of recovering from hurricane Katrina.

I'll send theman E-mail and see how the diesel is going.

Bill


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## jwalin (May 7, 2008)

Bowser330 said:


> Thanks for the math thats exactly what I needed...but a few more questions too..
> 
> How do you know a 10kw genset it putting out 69A?


P=IxE where P is power, I is current, and E is electromotive force (voltage) We were talking about a 144V system and 10kW, so 10,000/144=69.4444...



Bowser330 said:


> And I am not sure how to answer your final question, does the answer rely on the AHs of my battery pack? So if i have a 144V pack with 70AH does that mean the pack will power the motor in a steady state for 10 hours? with a draw of only 7 amps? (of course i understand WITH the genset on)


Yes, it depends on the AH of the battery pack. If your pack was rated at 70AH for a 7 amp draw, then you would have 10 hours. For an example look at the Trojan website and they rate their batteries at a 25 amp and a 75 amp draw, and give the reserve time in minutes. The J-150 12 V battery will give a reserve time of 280 minutes (4.6 hrs) at 25A. It will be much longer with only a 7 amp draw because of Peukerts. They also rate the battery with a 5, 20, and 100 hr rate (c/5, c/20, and c/100). At the c/5 rate, you could draw 120AH from the battery, which would be a 144v x 120AH = 17.3 kWH battery pack. This would be 12 Trojan J-150's, and weigh about 1008 lbs.


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## jwalin (May 7, 2008)

weelliott said:


> I've done quite a bit of research on this. Apparently when you buy a 10KW genset they suggest it be powered by a larger motor than simply one putting out 10KW. 10KW is about 13.3 HP. However, they suggest a 20HP motor. So I'd think that a 10 horse Kubota could only really power a 5KW genset.


Yes, that is right. ICE numbers are peak numbers, and most don't want their equipment running at peak power output for reliability's sake. For a 10kW generator, you would need at least a continuous 15hp WELL DESIGNED engine.



weelliott said:


> So looking at a ten horse engine We could get 5KW out. This 5000 watts would give us say 50 amps on a 100 volt system. Or if you were running a 144 volt system it would only yield about 35 amps. I think that 35 amps in most cars is only enough for constant speed driving at slow speeds you might experience in residentail areas. You'd need a bit more power to hit the 90% goal proposed earlier, which I think is a good goal. I can see maybe lowering our expectations to an 80% goal, but even with that, the 10HP engine won't quite hit the mark.


Again, this is correct. With the 5kW genset, you would get about 50% of what was proposed earlier. But this is still a range extending genset, just not as much of a range extension! But, I think even a 5kW genset would satisfy most of us in our need to extend our range. I would not turn it down!



weelliott said:


> ...... wiseman engines......


That is pretty cool....my only concern is the force applied to the eccentric shaft would be in a bending manner, and this would have to be pretty strong.

If you ask me, the Wankle rotary engine is one of the most ingenious designs of an ICE ever. Even the Wiseman design has to have valves and camshafts and lifters and all....hell it even increases the parts count and the labor to build over and standard crankshaft ICE. But the Wankle does not have valves, or a camshaft. It has so much more potential than what it is currently used for....

Jeff


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## weelliott (May 12, 2008)

A rotary is great in the parts count and simplicity respects. However, there is no way to raise the compression ratio in a wankle, and it is a relaitvely low ratio. I am not sure what it is, but I know that non-turbo rotaries can run 87 with absoutely no problem, and mildly turboed ones can even get away with it most of the time. The low CR means low efficiencies, and also that adapting it to a diesel application would be difficult. Perhaps impossible. I say perhaps because a turbo might be able to get the pressure up high enough to cause combustion, but I don't know. Startup would need either spark or compressed air or something.

As far as the Wiseman engine, I'm not sure what you mean by the shaft being in bending. Are you talking of the output shaft? It could easily be supported by a bearing in a transmission or in the genset or if a belt drive is used some pilow blocks to support the other end of the shaft would alleviate the forces putting the shaft in bending. You could also just size the shaft looking at the van meising(sp?) stresses assuming a certain amount of radial load on that shaft. A well designed shaft would have that analysis done on it. 

The method of getting gasses in and out of a rotary leads to less than ideal combustion, causing higher pollutants than other ICEs. So even though there aren't any power sapping valves, it is dirtier.

The big advantage of the wiseman is that it doesn't have the friction on the cylinder walls created by the piston being forced up against the walls by the connecting rod. This is a very significant friction. When honda designed the 3 cylinder for the insight it actually offset the crank so that the friction would be lower on the power stroke. They claimed a significant increase in efficiency from this.

Actually here is a clip from their press release on the insight.

"An unusual feature of the engine's design is that the crankshaft axis has been shifted, or offset, 14 mm, relative to the cylinder-bore axis. In other words, the crankshaft does not sit directly under the cylinder. This was done in the interest of minimizing friction caused by the side thrust of the pistons against the cylinder walls, just after top-dead-center, as each piston begins its descent on the firing stroke. 


In a conventional engine, piston-side thrust and the friction it generates are the result of the crankshaft's resistance to turning at this point. This resistance is the result of the small angle formed by the crank throw relative to the centerline of the piston and cylinder. The IMA engine's cylinder bores are offset to be over the crank throw at this point, so the piston and connecting rod push straight down, thereby minimizing side force on the piston. 
Cylinder-bore offset in the IMA engine accounts for as much as a three-percent reduction in internal friction."

The manner in which the piston travels through the stroke on the wiseman also compresses the gasses and delivers the force of the power stroke to the crankshaft more efficiently. There are charts up on their site explaining this. I'm quite impressed with it. 

The wiseman has realized a 50% decrease in fuel consumption, which I think is remarkable.

I know it will probably never see world wide use, but if they were to sell a 10 or 20 horse engine, I'd give it a try.


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## jwalin (May 7, 2008)

weelliott said:


> A rotary is great in the parts count and simplicity respects. However, there is no way to raise the compression ratio in a wankle, and it is a relaitvely low ratio. I am not sure what it is, but I know that non-turbo rotaries can run 87 with absoutely no problem, and mildly turboed ones can even get away with it most of the time. The low CR means low efficiencies, and also that adapting it to a diesel application would be difficult.


The rotary can use lower octane fuel because combustion happens over a longer time period, and there are two spark plugs to help with flame propagation. They really don't have a lower compression ratio, as the non turbo can have a rotor with a 9.7:1 ratio (89-92), and the stock turbo ran 9:1. It does not have to be lower in a rotary, it is just that the octane is not as much of a concern.

As far as emissions, well, you got it right there. The exhaust gasses run extremely hot in a rotary, and there won't be much unburnt fuel in the exhaust, but the killer is lubrication for the apex seals. Mazda always injected some oil into the intake to lubricate these seals, and this is the main reason why the rotary has more trouble with emissions. They got it a lot cleaner with the Renesis engines.

As far as diesel, I have never seen a diesel rotary. I have no idea if it could be made, but other fuels would work.

The 'shaft' I was referring to is the eccentric shaft (the yellow shaft in their animation) that the 'connecting rod' on the Wiseman rides on. This is essentially the same as the eccentric shaft of a rotary, just slightly different in configuration. I am sure that this would be accounted for in the design, and it does seem that this is a promising design for an ICE.

Please keep us posted of what you find on the diesel version.

Jeff


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## weelliott (May 12, 2008)

The shaft on any ICE is loaded in bending between the two bearings on each side of where the connecting rods connect. I don't really see a practical way to get around that.

I did not know that the compression ratio was adjustable. I had been told years ago that the shape of the rotor and the chamber that it rotates within are dictated by the way it rotates and both are pretty much unchangeable. This actually holds promise than because I'd think that the lubricating properties of biodiesel might allow the seals to work fine without having to add oil that would hurt emissions. Unfortunately ULSD has horriible lubricity, so it wouldn't be as ideal. The high temperatures that a rotary runs at would be made even higher if it were a diesel. I wonder if the temperatures would be too high. 

As far as the wiseman engine goes, I E-mailed Jerry Blankinchip, who is the guy that I had talked to before, and he replied that he would have the president of the company reply to my E-mail once he returned from a business trip. That should be early this week.

Bill


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## mountnmaniac (Aug 6, 2008)

Guys,

I have been headed down the Series Hybrid path myself. 

I have to be honest though when it comes to driving I'm a typical American. I live in Colorado and currently drive a 4wd pickup most fo the time. And that ain't changing.

My thoughts are though since I only need 15 miles for a commute that is not an issue with a bigger vehicle. 

As far as Diesel engine if you read the book 'The Zero Carbon Car' they actually contacted Fisher Panda for a Diesel Genset for a Boat/RV and had some custom designing to fit it in a trunk of the Mazda Miata. 

While I am fairly new in the Hybrid / EV area and still have a bundle to learn my thoughts went out to using Nimh or Lipo batteries and also thought of incorporating some Ulta Capacitors for passing and acceleration. Finshing off with a custom genset say in the 40 - 60 KW range and probably about 30hp Diesel Fisher-Panda as they are very effecient and have a good epa rating. I will need at least a 40 - 60 HP AC Motor coupled directly to my transfer case so that 4wd is still available.

Just an American that doesn't want to drive a prius...


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## fevoris (Sep 22, 2008)

I started a thread called "Prius conversion" before finding this one. I posted photos of my project. This all started when I bought a wrecked '03 Prius which was hit in the nose. I also bought an '02 totaled roll over for less then $1K incase I needed any parts. As it turned out I did not need anything so I ended up with everything from the steering wheel forward including the fire wall. I also had a few kit cars laying around for many years. One is a never assembled Jag convertable complete with frame that the Prius set up would not fit as the frame is designed for a V6 Ford. I also had a '32 Alfa Romao elect kit car I built in the '70's this is donating the rear end complete with transaxial I also have a '67 Jamacan kit car that will accept the Prius fire wall and dash as a perfect fit so that is the one I am building. Please check out my post in the other thread and give me some advice---thanks in advance.


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## unclematt (May 11, 2008)

Its too bad that Moller's rotaries are either overpriced or non-existant. His new plans for a compound rotary would be PERFECT for on onboard gen. For those unfamiliar with this design, one rotor supercharges the other rotor. Combustion only occurs in one, while the other acts as an exhaust driven supercharger.

Has anyone ever purchased a normal rotapower rotary by Moller? They seem like the perfect motor for this kind of project. They utilize an air cooled rotor and ceramic coatings that retain heat in combustion chambers to increase efficiency. They also run really well on ethanol...


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## unclematt (May 11, 2008)

On the topic of Moller, he has designed something he calls a "rotapac" which is a 25Kw to 35Kw gen set powered by his rotary 150cc rotary engine. The idea sounds great on paper, but this article is from 2007, and STILL no product on the market. Much like his air car (ahem) Here is the article from 2007: LINK


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## unclematt (May 11, 2008)

weelliott said:


> The shaft on any ICE is loaded in bending between the two bearings on each side of where the connecting rods connect. I don't really see a practical way to get around that.
> 
> I did not know that the compression ratio was adjustable. I had been told years ago that the shape of the rotor and the chamber that it rotates within are dictated by the way it rotates and both are pretty much unchangeable. This actually holds promise than because I'd think that the lubricating properties of biodiesel might allow the seals to work fine without having to add oil that would hurt emissions. Unfortunately ULSD has horriible lubricity, so it wouldn't be as ideal. The high temperatures that a rotary runs at would be made even higher if it were a diesel. I wonder if the temperatures would be too high.
> 
> ...


Hey Bill, did you ever hear back from the people at Wiseman Engines? I am curious since I have been thinking of building an engine based on their crankshft design.


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## mill (Aug 22, 2008)

i had an econmical idea guys, my friend works at a marina and he has a bunch of small diesel gensets from large yacts laying around, aparently when a boat sinks or fills up with rainwater on land while not in use (they call this "sunk on land") the owner usually just opts to yank them out and put new units in instead of fixing them. since they were not running the diesel engine and generator need minimal repairs to get them going, if they were not under too long. from what i hear they run along time. they are stuffed into tiny compartments on boats sometimes so they are very compact and are already wired for remote on/off functions. they generate ac current so you would need some sort of bridge rectifier at minimum but im sure one of you brainchilds on here will figure it out. if you live near a major waterway you may be able to pick one of these up for cheap.


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## drdonh (Aug 8, 2008)

An idea I was pondering for a range extender would be to use a suitcase style generator like the one here:


http://www.makita.ca/index.php?event=tool&id=391&catid=46

At 50 lbs, weighs less than a battery, and should help somewhat at extending range, or help keep the batteries from going into life shortening deep discharges. At 1400 watts it would supply just enough AC to power the on-board charger, greatly simplifying its installation. A direct production of DC would involve less losses, but would be more complicated (beyond my skills anyway). 

Depending on your driving pattern, perhaps the extra amps (probably 10 or so) is not too useful, but for low speed, stop and go driving it may be enough to make a difference.


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## DIYguy (Sep 18, 2008)

I have a pick up truck that I am converting. Eventually, I would like to do what this fellow did... but with a more efficient Diesel genset. I think it would be nice to be able to remove the generator when required also. 
http://www.evalbum.com/122.html


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## evcars (Mar 15, 2008)

DIYguy said:


> I have a pick up truck that I am converting. Eventually, I would like to do what this fellow did... but with a more efficient Diesel genset. I think it would be nice to be able to remove the generator when required also.
> http://www.evalbum.com/122.html


 
That's pretty cool. A 10kw gen head like this would push the range a bit. 

http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=45416

My question is still how do you convert the generators ac power to be useful in a dc car? Don't want to use the battery charger.


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## DIYguy (Sep 18, 2008)

xtreme cartz said:


> That's pretty cool. A 10kw gen head like this would push the range a bit.
> 
> http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=45416
> 
> My question is still how do you convert the generators ac power to be useful in a dc car? Don't want to use the battery charger.


you will need a full bridge rectifier and capacitors to smooth it out likely.


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## Electric_Rav (Aug 11, 2008)

I was thinking of using two of these (the SCS24) which put out 150 or so volts at 6000rpm wired in parallel hooked up to a 22 HP Honda Vtwin (geared up to get the PMAs up to 6000 RPM). I would think I should have at least 100 amps at 150volts by the looks of their graph. I plan on purchasing at least one PMA for testing in a few months. I'll hook it to a 16HP Vtwin Briggs and Straton and make it spin up to 6000RPM then put a load on it to see how much the voltage sags. Their graphs say unloaded ratings but how do you know how many amps you have if you don't load it down?

I'll have a standard ADC motor with a curtis controller and 144 volt system and I figure my amp draw at 60mph will be about 80 to 100 amps (Toyota RAV4). I drive up to 80 miles a day but this is usually going to 6 different places and the vehicle sits for 40 min at a time. The Batteries should recover some I would think plus if I can put a few amps back in them at the rated charge rate of 50 amps then I should be doing OK I hope.


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## buzzforb (Aug 16, 2008)

Don't know if you guys would be interested in looking at Hatz diesel eninges. They have a line of silent engines in cases that run at about 60-70 dB which may be a consideration in your proposed builds. They would be more expensive than say a Honda V-Twin but probably tougher, more powerful, and more efficient.


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## Electric_Rav (Aug 11, 2008)

I've looked into Hatz and I would love to use one but they are somewhat expensive. My budget would not allow it but I'm keeping a keen eye out for slightly used ones. For others considering a hybrid build a good diesel may be the way to go if you can keep the emissions to a minimum.


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## tj4fa (May 25, 2008)

I've always been interested in adding a small engine and spinning up a generator head to extend range by charging the battery pack as I go or run the DC motor directly.

I sent in a question to an eBay seller who sells a variety of sizes of generator heads about using one as a range extender.

Here is a copy of that conversion (added here with his permission).




tj4fa said:


> I have built an electric vehicle that currently uses 144VDC battery system driving a DC series wound motor. I am researching making the truck into a series hybrid with some others on a message board who have built similar vehicles and I wonder what would it take to get this generator head to put out 17kw-20kw continuous @ 144VDC-156VDC (give or take) if coupled with a small gas engine. I anticipate that 17kw could power the electric motor directly as a range extender to the current battery only operated Electric Vehicle.


Item I was inquiring about---> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=160300904689&ssPageName=ADME:X:AAQ:US:1123

His reply: 



> Hi Terry,
> Interesting ideas you have!
> just spin the gen a little faster, parllel the windings (easy do in the top of the gen) and rectify the AC output to make DC. can make any voltage you like.
> Thanks and hope this helps


Now this one seems large but suppose if you can pulley up a generator head and spin it a lot faster say double it. Would that do the job?


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## Electric_Rav (Aug 11, 2008)

Weight: 386 LBS!


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## tj4fa (May 25, 2008)

Electric_Rav said:


> Weight: 386 LBS!


Yeah it is kinda "heavy duty". 

How 'bout spinning up a 12KW generator head twice as fast?


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## tj4fa (May 25, 2008)

Wow...I'm a regular thread-killer. 

Ok how about this...

I get a 40KW 3-phase 400hz Aircraft Generator that at 6000 RPM puts out 120/240VAC and 111 Amps that weighs approximately 70lbs and is about 10" in Diameter and about 14" long.

Then I get a small gas or diesel engine (CARB) approved for emissions that at normal RPM of 3000 RPM and pulley the generator up to spin it at its rated 6000 RPM.

I then install a full-wave bridge 3 phase 400hz rectifier rated at 150A and 800V to convert the AC to DC and then either:

-Run it through my 144VDC battery pack and Curtis 500A speed controller to power the ADC FB001A series wound DC motor
in conjunction with the battery pack.
or
-Put it on a transfer switch and run it straight through the speed controller to the DC motor for extended range use.

-Would 40KW be enough to run the motor full-time?
-Would the generator supply too much through the battery pack and hurt it?

Am I dreaming here? Where am I screwing up in my thinking? 

Thanks for any input positive or negative.


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