# Why are there no on board generators?



## fixityourselfer (Aug 23, 2009)

Hello everybody.

I'd like to know why nobody has ever decided to mount a on-board generator to use when battery power drops too low?? 

even if it uses gas, many would appreciate having the extra range, and it would probably be quite efficient cuz you're not revving the engine up and down with a throttle, nor are you losing efficiency by shifting gears. 

plus the chevy volt does either this or something similar.

why don't we all add a on-board generator to our EV's????


----------



## Bowser330 (Jun 15, 2008)

fixityourselfer said:


> Hello everybody.
> 
> I'd like to know why nobody has ever decided to mount a on-board generator to use when battery power drops too low??
> 
> ...


Several topics on this and i've gathered a few reasons from the previous posts...

This is the DIY ELECTRIC CAR (not DIY HYBRID ELECTRIC CAR)

(a) Many people are not concerned with range of more than what they 
are getting now, as they are being used for local/commuter cars.

(b) Many people are converting partly for the environmental reasoning


Note: The cheapest combination i've found is to build your own genset using a small engine and generator head. 10kw for 1500$ and about 250lbs (with all brackets and chassis mounting brackets) I am not sure how fuel efficient the small engine is though...3000$ and 500lbs for 20kw...hmmm....


----------



## Sunking (Aug 10, 2009)

Because it wouldn't be an EV anymore, it would be a hybrid. There is also quite a problem with weight and space, and you wouldn't gain any more distance because you would have to give up some batteries.


----------



## fixityourselfer (Aug 23, 2009)

is it something like this that would do the job?

(I hope I'm not making a major error about the type of generator I'm thinking of)
http://cgi.ebay.com/John-Deere-9750...ain_0?hash=item230292db9d&_trksid=p3286.c0.m1

It doesn't weigh TOO much, and seems it would do the job. price good too. I'm guessing such a machine would consume around .8-1 gph. travelling at 55mph that would mean somewhere between 55-66 mpg with gen running.

please correct me if I'm making a nooob error somewhere in my calculations!!!


----------



## 280z1975 (Oct 2, 2008)

fixityourselfer said:


> is it something like this that would do the job?
> 
> (I hope I'm not making a major error about the type of generator I'm thinking of)
> http://cgi.ebay.com/John-Deere-9750...ain_0?hash=item230292db9d&_trksid=p3286.c0.m1
> ...


I'll try to answer your questions as best as I can.

this generator is 6.7kw hours of power, which for most people when run a 144 volt system means 46.5amps of power ... which isn't quite the power needed to sustain a normal 2,500lbs vehicle at highway cruise.

You would also have to deal with the idea of more electrics to deal with the charging on the go, the storage of the gas, the space of the generator, etc. ... in the end if you want it to be cheap a gen set is not the way to go. To much hassle for the benefit.


----------



## dtbaker (Jan 5, 2008)

fixityourselfer said:


> why don't we all add a on-board generator to our EV's????


well.... cuz then they would be hybrids, not EVs. The whole idea is to get completely away from that dino-juice ya know....  

but more seriously, for the average vehicle, to get enough wattage to contribute directly to the drive, the generator would be BIG and expensive and heavy and take a lot of room that could otherwise be used for a couple more batteries.

A successful EV experience demands a bit of an adjustment to expectations. Its probably not going to be a race car or a x-country RV.... but it CAN be a very practical in-town commuter.

d


----------



## Woodsmith (Jun 5, 2008)

Wasn't there a chap here who is planning on towing a huge generator on the basis that he is a mobile welder and so the set is his living as well as his range extender?


----------



## fixityourselfer (Aug 23, 2009)

280z1975 said:


> this generator is 6.7kw hours of power, which for most people when run a 144 volt system means 46.5amps of power ... which isn't quite the power needed to sustain a normal 2,500lbs vehicle at highway cruise.


thanks for your reply.

if that's the case, then if this doesn't do it, at 55.5 amps for a 144v vehicle,(253 lb gen. remove cart & wheels, gets u to 225 lbs or so. too much?)
http://cgi.ebay.com/Power-Max-Porta...in_0?hash=item2ea6ea90a1&_trksid=p3286.c0.m14

......

this one will, at 104 amps of power for a 144 volt vehicle, but it's probably to darn big and heavy. i'm just trying to calculate it's WEIGHT cuz it may kill the whole car, even a chevy s10 conversion. am thinking chevy s10 cuz there's often space left over in the back of the bed, definitely for the 55 amp model.
http://cgi.ebay.com/ONAN-15-KW-gene...tors?hash=item2a0099f52a&_trksid=p3286.c0.m14

I'm curious. is the extra hassle the main reason no-one does this?

my commute to work has been 65 miles. i'd love to build a vehicle that can get there with a on board gen running for the last 20 miles or so, 
then plug in at work and do the same on the way home!


----------



## neanderthal (Jul 24, 2008)

A few more reasons are: 
Generators don't have all the emissions stuff, and they put a ton more crud in the air, in some states it would not fly

It's not super efficient without the right gear With a plain generator you turn combustion energy into mechanical energy into ac electric energy then into dc electric energy then back into mechanical energy

A charger for this type of setup is very expensive 3000-5000 usd is a deal

I have seen some very successful ones done using a small motorcycle engine driving a purpose built generator that pumps juice directly into the batteries. The moto engine is better on fuel and emissions and the whole setup is more efficient They claimed to get better mpg than the vehicle did with the gas motor. 

The motor providing cruising power for more range is definitely an option, but to pull it off well, with good emissions and efficiency, I think you end up spending a good amount of money.

Most of us have a gas car for long trips and en ev for shorter trips, so I think that's another reason a lot of us have not done something like this


----------



## IamIan (Mar 29, 2009)

It boils down to break even points.... and how much you are willing to give up for the convience for those rare trips it might be useful.

That Generator costs will weigh ~100 kg... and will only provide ~6.2 kW at a continuous rate.

This generator is using ~100 kg of weight... with LiFePO4 giving ~100Wh/kg ... in order to put this generator on board you are giving up 10kWh of battery capacity worth of weight.

If that 10 kwh you gave up would have allowed you to just use the EV and no gasoline ... you would have been better off / more ahead if you had just used the 10 Kwh of battery instead.

This generator will not provide for the peak power surges a EV will need during acceleration and such... so an additional battery pack would still be needed for those peak power times.

Generators like this could be used to extend the range of an EV ... how much depends on the efficiency of the EV and the average speed of travel ... even a 6 mile / kwh EV which is a pretty good number to reach ... could only travel at ~35 MPH under the power of this generator... The Volt is looking to use a ~50kW generator to be able to provide enough juice... which still does not handle the peak loads they are expecting of over ~110 kW... so an additional ~16 or so kWh battery is also included to handle the peak power needs / loads.

Range extention gasoline powered generators would be better used ( in my opinion ) as built into an easily detachable trailer... that way the extra 100+ kg of weight can be left at home on those trips that the extra range is not needed... as in ~80% or more of ~80% of the trips ~80% of the population makes.

The attraction to having it built in as GM is doing with the Volt is just for convience ... they are giving up allot ... in order to have that conveince ... for a small % of trips ... but it might work to sell it to the public.

Hopefully once the public starts to buy some of these REEVs & some of the PHEV like the Volt and such ... hopefully people will begin to see a bit of the reality of how rarely they ever use the extended range feature ... hopefully it will open the eyes of the public to see that it isn't needed... and then like pulling other trailers for boats and things ... people will leave the range extention generator at home like they leave boats and such ... when they won't be needed them... and just drive normally as a EV for the majority of thier trips.

----------

As for the efficiency ... a generator can be more efficient ... but it might not be ... it will depend on exactly how it was built... that particular generator is not particularly efficient.

For that Generator to use ~1 Gallon of gasoline in ~1 Hour .. and put out ~6.2 kWh in that ~1 Hour ... that generator is converting the ~36.6kwh of energy that 1 gallon of gasoline only at ~17% efficiency... even if your electric motor is ~90% efficient that means you are only ~15% efficient from gas tank to wheel... Modern efficient gasoline engines are allot more efficient than this... it isn't that hard to get a modern gasoline engine to get closer to ~30% efficient.

Even a modern ~30% efficient ICE attached to only a ~80% efficient generator / alternator ... would still yield ... ~24% efficiency gasoline to electricty ... which is still significnatly better than this example generator.

----------

I seriously doubt that generator would pass emissions tests ...


----------



## IamIan (Mar 29, 2009)

fixityourselfer said:


> my commute to work has been 65 miles. i'd love to build a vehicle that can get there with a on board gen running for the last 20 miles or so,
> then plug in at work and do the same on the way home!


So if you can plug in at work you want a EV with a ~75 Mile Winter Range.

A EV at ~4 Miles per Kwh ... you would need ~20 kwh... less if you can get your EV more efficient... can be done but gets tricky... ~5 Miles per kwh would reduce your battery to ~15 Kwh.

20kwh from ~100 Wh / kg LiFePO4 ... would weigh ~200 kg ... and at ~$300/kwh would cost ~$6,000.

For 15 Kwh ( 5 Mile / kwh ) .... 150 kg.... ~$4,500.

----------

If you can't Plug in at work you currently need double that or ~40kwh... ~400kg.... and ~$12,000 worth of batteries.

for 5 mile / kwh .... ~30 kwh .... 300 kg ... ~$9,000

----------

If I assume you travel at about an average speed of ~50 MPH from home to work ... a generator ( 4 Mile / Kwh ) would need to put out ~13 kW... or 13,000 Watts in order just to keep up.

For a 5 mile / kwh EV .... you would need a generator ~10 kW or 10,000 Watts just to keep up at ~50 MPH average speed.

----------

so how much $ ... weight ... and space would a ~13 kW generator cost you?... I think you'll have a hard time getting under ~200 kg.... which is giving up ~20kwh worth of battery weight for the generator.... that ~20kwh of battery weight would get you from home to work via battery power alone instead of using the generator.


----------



## Bowser330 (Jun 15, 2008)

IamIan said:


> For a 5 mile / kwh EV .... you would need a generator ~10 kW or 10,000 Watts just to keep up at ~50 MPH average speed.
> 
> -------


20-hp small engine 800$ 90lbs

10kw generator head 800$ 120lbs.

I am interested however in the motorcycle engine idea...


----------



## IamIan (Mar 29, 2009)

Bowser330 said:


> 20-hp small engine 800$ 90lbs
> 
> 10kw generator head 800$ 120lbs.
> 
> I am interested however in the motorcycle engine idea...


Perhaps...

Just remember every ~100 lbs of generator is about ~5 kwh worth of batteries you are not carrying... 120 + 90 = ~210+ Lbs ... for that ~10kW generator you are loosing ~10kWh worth of batteries.

The generator will take more than 1 hour in order for it to produce more than the 10kWh you lost by putting it in... and batteries would still be needed as the ~10kW generator can not deal with the peak kW surges that batteries can.

But for those much much longer trips... like 2+ Hours each way .... sure a generator like this could be useful... but given how rarely that would be needed I still prefer to removable generator trailer that is not a permanent part of the vehicle.

Just my own personal preference.


----------



## Bowser330 (Jun 15, 2008)

IamIan said:


> Perhaps...
> 
> Just remember every ~100 lbs of generator is about ~5 kwh worth of batteries you are not carrying... 120 + 90 = ~210+ Lbs ... for that ~10kW generator you are loosing ~10kWh worth of batteries.
> 
> ...


I agree with you about making the genset removeable when not needed, I would like to make mine "easily" removable for those times when a longer trip would be required...also peak KW would be drawn from the buffer pack of A123 or LiPoly cells...im not planning to rectify my genny straight to the e-motor...

Also...check this out...

http://green.autoblog.com/gallery/fev-wankel-range-extender/
63kg = 18kw output (petrol or much cleaner LPG)

2 of these would weigh...277lbs with 36kw of output...hmmmmmm


----------



## tj4fa (May 25, 2008)

The way I see it, as long as it's propelled with an electric motor, its an ElectricCar.

One day I dream to do this -->http://www.evnut.com/rav_longranger.htm

With some of this stuff --> http://s117.photobucket.com/albums/o42/jaynethecat/Range Extender Stuff/


----------



## COS (Dec 23, 2008)

tj4fa said:


> The way I see it, as long as it's propelled with an electric motor, its an ElectricCar.
> 
> One day I dream to do this -->http://www.evnut.com/rav_longranger.htm
> 
> With some of this stuff --> http://s117.photobucket.com/albums/o42/jaynethecat/Range Extender Stuff/


 
I remember the story on that guy with the rAV4. He convinced the folks at AC Propulsion to sell it to him because the deemed the trailering was not the biz they wanted to get into for an EV. They (AC Prop) used it on ta yellow model TZero on a cross country run. 

The motorcycle genset idea is good. You can get a 400cc Yamaha FZR engine and adapt/mount two 120VAC generators (http://www.blastwholesale.com/proddetail.php?prod=GSH11158) to it you'll get ~20KW average and 24KW surge. Stay at ~20KW though. All you'll need is 26.8HP average so if you can tune the 400cc motor for best efficiency at the required 3600rpm - 4000rpm to ~55-60HP then you'll have an awesome genset that can work as both your range extender or power your house in a blackout.

Once you rectify the AC out from 120VAC you should get (120*1.414) - (1.4V ["diode loss"] + 12.0V ["Ripple voltage lost" after filtering]) = 156.28VDC. This should keep your 156VDC pack close to 80% SOC.

There much more to do but you got the idea right?
________
Live sex


----------



## COS (Dec 23, 2008)

Bowser330 said:


> Also...check this out...
> 
> http://green.autoblog.com/gallery/fev-wankel-range-extender/
> 63kg = 18kw output (petrol or much cleaner LPG)
> ...


That genset is a mating of the Aixro XR 50 Rotary/Wankel engine:http://www.race-sport.net/aixro-xr-50-wankel-specs/ to a UQM AC induction generator/motor. It only looks small and compact becausse they removed all the other stuff. Don't let it's current picture fool you, you need the carb, cold air intake, exhaust pipeline, water colling/radiator (oil or other) as well as the generator controller power electronics, etc. It'll be close to twice the size of that pic. 

Here's a site that shows you what the rotary engine looks in a go kart: http://www.zercustoms.com/news/RENNtech-Aixro-XR50-kart-engine.html
________
Live Sex


----------



## Sunking (Aug 10, 2009)

fixityourselfer said:


> I'm curious. is the extra hassle the main reason no-one does this?


Well what everyone is dancing around is PHYSICS. If you were to put in a large enough engine to turn a large enough generator to power your vehicle, you wouldn't need the electric motor or batteries.

In other word the Laws of Thermal Dynamics. An engine (ICE) and generator of very inefficient, meaning no energy gain, only a loss, a huge loss. 

A 3000 pound vehicle needs about 200 watt-hours per mile to maintain a 60 MPH. That means a 15, 000 watts, or a 18 HP ICE to generate 15 Kw with 80% efficiency.


----------



## samborambo (Aug 27, 2008)

An AC genset with a slip-ring (not permanent magnet) alternator could be adapted to charge the batteries, etc. A PI based regulator circuit could regulate the (normally 12V) rotor slip-ring voltage to give a constant current output to charge the battery.

I quite like the idea of a genset trailer for my MR2 conversion. NZ is quite spread out and there's definitely need to travel 400-500km quite often.


----------



## Bowser330 (Jun 15, 2008)

COS said:


> That genset is a mating of the Aixro XR 50 Rotary/Wankel engine:http://www.race-sport.net/aixro-xr-50-wankel-specs/ to a UQM AC induction generator/motor. It only looks small and compact becausse they removed all the other stuff. Don't let it's current picture fool you, you need the carb, cold air intake, exhaust pipeline, water colling/radiator (oil or other) as well as the generator controller power electronics, etc. It'll be close to twice the size of that pic.
> 
> Here's a site that shows you what the rotary engine looks in a go kart: http://www.zercustoms.com/news/RENNtech-Aixro-XR50-kart-engine.html


crap...just typing "UQM" made it unaffordable and unavailable..


----------



## COS (Dec 23, 2008)

Bowser330 said:


> crap...just typing "UQM" made it unaffordable and unavailable..


I know, it sucks ass when these companies sell only to OEM and costs an arm, leg and testi.
________
Velvettouch


----------



## Bowser330 (Jun 15, 2008)

COS said:


> I know, it sucks ass when these companies sell only to OEM and costs an arm, leg and testi.


I wonder how many kws one of these airmotors produces...

http://www.engineair.com.au/airmotor.htm

They are pretty small...

I am going to be in Melbourne in a few months so I will see if I can go to this market to verify these airmotor carts...maybe even smuggle one home..jk


----------



## dragster (Sep 3, 2008)

There is an infrastructure in this country called gas stations and the public is very well aware of it. There is no infrastructure for electric plug in cars and the public is well aware of it. There is not going to (EVER) be electric plug in cars with the thinking of the people on this site. They just don't get it!!!


----------



## PartsMan (Aug 20, 2009)

A small gen set could mean driving 20mph home instead of walking.

I don't know about 144v but a plan old alternator can be made to charge 48v with a different regulator.

Convenience stores should really offer cheap/free charging for EVs. We just need to explain to them that there will be customers stuck shopping while ther car charges.


----------



## Bowser330 (Jun 15, 2008)

dragster said:


> There is an infrastructure in this country called gas stations and the public is very well aware of it. There is no infrastructure for electric plug in cars and the public is well aware of it. There is not going to (EVER) be electric plug in cars with the thinking of the people on this site. They just don't get it!!!


There is an infrastructure for plug in electric cars, its called the electrical grid and MORE people are aware of it and use it than the gas station infrastructure.

Would the grid need to be upgraded/enhanced as more people get EVs? Yes. Does the full grid upgrade have to happen right now? No. It can happen slowly just like the adoption of EVs...

Can existing gas stations/convenient stores/hell near anywhere be retrofitted to have EV charging stations as well? Yes.

I think the people on this site do get it and thats why we are here talking about what we talk about. 

However please enlighten us with what you do get? I, as well as a many other really smart members of this site would like to know...


----------



## dragster (Sep 3, 2008)

If an EV driver finds he or she needs a quick charge because traffic was diverted around an accident. You say all they need to do is find a convenient store and plug it in to 220 volt. you can't use 110 volt as it is to slow. If I am Joe Public and this is what I have to do then you will (never) see electric plug in only cars on the roads. No intellengent person is going to buy a plug in only car with out a GENARATOR.





Bowser330 said:


> There is an infrastructure for plug in electric cars, its called the electrical grid and MORE people are aware of it and use it than the gas station infrastructure.
> 
> Would the grid need to be upgraded/enhanced as more people get EVs? Yes. Does the full grid upgrade have to happen right now? No. It can happen slowly just like the adoption of EVs...
> 
> ...


----------



## azdeltawye (Dec 30, 2008)

Bowser330 said:


> There is an infrastructure for plug in electric cars, its called the electrical grid and MORE people are aware of it and use it than the gas station infrastructure.
> ...


+1



Over 1.4 Million GWH in retail sales in the USA year to date...

http://www.eia.doe.gov/cneaf/electricity/epm/tablees1b.html


----------



## dtbaker (Jan 5, 2008)

dragster said:


> If an EV driver finds he or she needs a quick charge because traffic was diverted around an accident. ... No intellengent person is going to buy a plug in only car with out a GENARATOR.


I don't recall any detour ever taking me more than a block out of my way... but I might not be recalling correctly since I'm not that smart; having built an EV without a generator, silly me.


----------



## dtbaker (Jan 5, 2008)

*Re: air motors*



Bowser330 said:


> I wonder how many kws one of these airmotors produces...
> 
> http://www.engineair.com.au/airmotor.htm
> 
> ...


I can't see using an airmotor as primary drive.... every conversion of energy you lose efficiency, they are going to be loud, and range limited by the size/pressure of the tanks.

HOWEVER, I think they might have killer potential as a regen braking 'spring' with the tank sized big enough to suck up a braking event or a few charges on a long descent. The fire up to assist the drive side until the tank is depleted.


----------



## Bowser330 (Jun 15, 2008)

*Re: air motors*



dtbaker said:


> I can't see using an airmotor as primary drive.... every conversion of energy you lose efficiency, they are going to be loud, and range limited by the size/pressure of the tanks.
> 
> HOWEVER, I think they might have killer potential as a regen braking 'spring' with the tank sized big enough to suck up a braking event or a few charges on a long descent. The fire up to assist the drive side until the tank is depleted.


Oops, my bad, I didn't mention it specifically, but I posted about the airmotor thinking we could use it to generate some elctricity by mating it to a generator, totally 100% clean compressed air...(which could be refilled on the go as well) 

What do you think?


----------



## Bowser330 (Jun 15, 2008)

dragster said:


> If an EV driver finds he or she needs a quick charge because traffic was diverted around an accident. You say all they need to do is find a convenient store and plug it in to 220 volt. you can't use 110 volt as it is to slow. If I am Joe Public and this is what I have to do then you will (never) see electric plug in only cars on the roads. No intellengent person is going to buy a plug in only car with out a GENARATOR.


(1) How is it any different if a ICE driver needs a fill-up from a detour too? Infact the ICE driver may have a harder time finging a gas station compared to an EV driver finding any EV-Charging equiped site (in the near future)

(2) Well it wont be just another 220V outlet, I feel their will be charging stations that have stationary batterypacks which store enough energy to rush into a pack and charge it in minutes...These would be pretty easily installed. (the car battery packs of the future will be stronger like A123 cells that can take high amperage charges of 20-50C)

Is a genset a good idea right now...yes..why?...there hasnt been enough installation of charging stations....thats why you see me talking about generator options...why dont you try to cool off on the negative comments and "never never never" type talk and be proactive/help by finding some generator technology that can help bridge the gap till the battery tech can catch up...The community would like to know your ideas...


----------



## Woodsmith (Jun 5, 2008)

Isn't it a case that if you inadvertantly find yourself running out of charge you just have to stop somewhere for a little while and let the batteries recover a bit and then go a bit further?

I would avoid running that close to the limit in an EV in the same way I would avoid running on fumes in and ICE car so I don't see 'suddenly running out' as an issue.

For going the distance I guess I would plan my journey to include charging points in the same way I would with gas stations. The distance may not be as far but I would plan differently.

Don't forget that at the dawn of motoring petroleum spirit was purchased in 2 pint cans from the occasional drug store. Then some bright spark figured there was a business in selling pumped fuel to the motorist.


----------



## dtbaker (Jan 5, 2008)

*Re: air motors*



Bowser330 said:


> Oops, my bad, I didn't mention it specifically, but I posted about the airmotor thinking we could use it to generate some elctricity by mating it to a generator, totally 100% clean compressed air...(which could be refilled on the go as well)
> 
> What do you think?


well.... think that would be more conversions than required. spinning compressor via belt or gears to fill tank; then release tank to spin mechanical turbine would be ideal or reversible compressor to run the power back to drivetrain. BUT compressors are typically piston rather than turbine, and tend to be pretty loud.....


----------



## IamIan (Mar 29, 2009)

dragster said:


> If an EV driver finds he or she needs a quick charge because traffic was diverted around an accident. You say all they need to do is find a convenient store and plug it in to 220 volt. you can't use 110 volt as it is to slow. If I am Joe Public and this is what I have to do then you will (never) see electric plug in only cars on the roads. No intellengent person is going to buy a plug in only car with out a GENARATOR.


Disagree several ways.

#1> Only a poorly planed driver of any vehicle EV or Gasoline or other ... drives a route with exactly just barely enough to get there... same reason people don't walk around for miles with a gas can because a detour caused them to have to drive a few extra miles... and the same thing for people who run out of gas in the parts of the U.S. where the next gas station is 50+ Miles away.

I say if any driver ... even of a gasoline fueled car drives trips that close to running out of fuel... it is their own fault for running out of fuel... gas or electric, or hydrogen , etc.... the fuel typ doesn't matter the driver is at fault for making a bad choice.


#2> Like it or not electricity is more available than gasoline is.... and by a wide margin as well.... not even close.

#3> 110V will work just takes longer... but that's what the guy gets for pushing his fuel limits... same for the guy who runs out of gas and has to spend the time to walk to get some.... or spend the time to wait for AAA.

#4> Joe public is moving to EVs ... yes they want the generator safety net ... but that is just because they buy into the myth about how it will effect them not to have it... once they start learning more truth about the short distances they actually do drive... more and more of the joe public won't want the generator.

At most a generator is a cookie to pull more people in so they can see for themselves ... but the more people do see for themselves ... the less the demand will be for a generator... as they bust these myths of needing one.

#5> I think it would be nearly impossible for you or anyone to back up / prove such a absolute statement about the intelligence of every person in the world who has ever driven ... does drive ... or will ever drive a BEV... no part of the definition of intellegence relates to the vehicle one drives... if anything it is an obviously imflamatory statement desired only to insult other people who disagree with you... and it isn't effective... it only serves to discredit what you write ... stick to positive statements and avoid such unfounded attacks if you wish people to actually listen to what you have to say.


----------



## wenowhavepower (Dec 24, 2008)

Well i don't think it's a generator "myth", it's more like a safety net like you stated.
Even the greatest planners will have their plans changed.

As sad as it is, most people don't plan.

Also what's quicker, running low on fuel (gas) and stopping by a gas station, fill up in less than 10 minutes and on your way you go or stopping by 220 outlet and wait a few hours to charge?

Until we have the batteries and the quick charge stations, a generator will always appeal to the mass public.

I would love to be 100% electric only but i wouldn't want to be limited by the batteries/charge.


----------



## Woodsmith (Jun 5, 2008)

> I would love to be 100% gas only but i wouldn't want to be limited by the size of the tank, that's why I have a mast and sail and a horse box trailer with a horse and rope and I carry extra fuel in cans in the trunk.


Excuse the deliberate misquote but you might get the gist.

If I was driving across Australia I would carry all the fuel I could carry, a bike, a sail board, etc just in case. But I wouldn't on a drive where I knew it was within tank range and I could fill up at the other end for the return.

An EV should be like that. The driver would consider if the trip was within range. If not then other precautions can be taken if needed.
Mine would be a long charging lead and a map of EV friendly stops and EV club members with charging points. Charging would then take place when I stopped for a comfort break and a coffee and donut.


----------



## wenowhavepower (Dec 24, 2008)

Correct but not everyone will be able to do that and we are talking about mass public.

If i have a car (ev or not), my main reason on driving it, would be for speed and convenience.

Edit: speed as in to get things done faster...

Stopping to charge (for 1hr+) is not going to work out for lots of people and yes, you could say,use a regular car but then we will never get the EV charging stations etc because no one is buying/building the cars that requires them.

If all that requires (for a peace mind) is to have a generator for safety net, than so be it.


----------



## Woodsmith (Jun 5, 2008)

I have taken a lot of time to consider the option of a generator and to be honest I wouldn't bother unless I was out in the middle of nowhere, a desert for example. It would need to be one really big and heavy generator to be able to put in more energy in less time then plugging in will.
I wouldn't want it to be running while I am driving either, especially if it were in the vehicle and even if it were it wouldn't make sufficient difference for me given the extra weight I would have to carry to have it there.

If it were in a trailer then I would have the weight of the trailer as well and if I left it running while I was off enjoying myself then it probably wouldn't still be there when I returned. If I stayed near it then I would have the noise of running.

Maybe over in the UK we have 240v everywhere and that makes a difference to charging capacity compared to the USA and, apart from some parts of Scotland and Wales there is 240v pretty much everywhere.


----------



## samborambo (Aug 27, 2008)

Electricity may be everywhere but its not accessible unless there's fast charging (and billing) infrastructure available. You can't just open an underground pillarbox and connect jumpers to your car..... well, you can - just don't get caught. 

I wouldn't bother with a genset trailer if there was a sub-20min bulk charge available every 100km.

It'll happen - maybe not in the next 5 years or so though. I work for a power utility and it is an area of interest for developing charging infrastructure in the near future.


----------



## Bowser330 (Jun 15, 2008)

Okay so we dont have a charging infrastructure *yet*, but i do remember when the first wave of EVs came out in the 90s,(EV-1 Rav4 EV, Rangers, S10s, etc) They did start to build an infrastructure of charging stations all around major cities, that would have expanded had the EV programs not been killed by the same fools that are now begging for financial aid from the same people who they STOLE the EVs from...

Hey I am all for gensets, I wanted that one lightweight wankel version until i found out it was somehow associated with UQM..which essentially means they will sell it to you in a fair trade for one of your testis...(gotta give props to COS for that one)

I do agree that we will need gensets for now, and when the infrastructure is built to where people wont even have the gensets turn on..since they will be opportunity charging everywhere, store, mall, work, movies, etc....then we can start to make them smaller and less significant...additionally solar tech will be improving and other forms of alternate energy which can also help make the genset less relied upon...

We have to all agree that just as it was pointed out that the use of gasoline was phased in...it will have to be phased out....we shouldnt expect it to be so black and white...we have to give the oil companies a chance to buy the alternative energy companies and close them... oh sorry,...have them run around in circles and produce nothing...





wenowhavepower said:


> Correct but not everyone will be able to do that and we are talking about mass public.
> 
> If i have a car (ev or not), my main reason on driving it, would be for speed and convenience.
> 
> ...


----------



## Woodsmith (Jun 5, 2008)

samborambo said:


> Electricity may be everywhere but its not accessible unless there's fast charging (and billing) infrastructure available. You can't just open an underground pillarbox and connect jumpers to your car..... well, you can - just don't get caught.


It's been known for folks to 'borrow' electricity from dubious sources. 

I figured it wouldn't be a problem in the UK as news reports of EVs and the occasional car or gadget programmes seem to show people stopping outside a pub/bar and going in with a plug and asking for a charge up and buying a pint while they wait.
It should be fairly easy to work out the cost per hour of charge from a standard domestic outlet and then just offer that amount and a little bit for the trouble.


----------



## PartsMan (Aug 20, 2009)

Couldn't it be as simple as a 220v outlet with a quarter/dollar timer?
Right next to the pay air.

Charge twice what the electricity costs plus they will probably buy a Coke and a snack since they are stuck there for 30+minutes.

They could even make a feel good ad campaign.
______ is committed to being part of the solution so we will begin offering EV charging across the nation. 
Then there gas customers could feel better about buying from and oil company that cares.


----------



## Bowser330 (Jun 15, 2008)

PartsMan said:


> Couldn't it be as simple as a 220v outlet with a quarter/dollar timer?
> Right next to the pay air.
> 
> Charge twice what the electricity costs plus they will probably buy a Coke and a snack since they are stuck there for 30+minutes.
> ...


So not only do we have some seriously smart engineers on this forum, we also have some crafty marketing execs!

I do honestly believe it could be as simple as a creditcard swipe machine and an outlet...


----------



## Sunking (Aug 10, 2009)

Well I work in the electric utility industry and we have already concieved electric filling stations, it is a long ways off as the battery technology does not exist yet, but it goes something like this.

You pull up your vehicle. exit it and go inside to a safe area. Then an attendant pulls the car up on a steel platform (ground plane), The attendant connects the vehicle to the charging apparatus, which will have to be standardized to say 480 or 600 volt 3-phase. When charge is complete, the customer pays, the attendant disconnects, and pulls the car to the waiting area. Off you go 10 to 15 minutes later.

Basically to make it work the electric station will be a 69 KV or higher substation, depending on how many charge stations that can be operational at any one time. I mean 20 to 60 Kwh in 10 to 20 minutes is one hell of a lot load multiply that by 4 charge stations at one time and WOW.


----------



## tj4fa (May 25, 2008)

PartsMan said:


> Couldn't it be as simple as a 220v outlet with a quarter/dollar timer?
> Right next to the pay air.
> 
> Charge twice what the electricity costs plus they will probably buy a Coke and a snack since they are stuck there for 30+minutes.
> ...


We're so waaaay behind the power curve.


----------



## PartsMan (Aug 20, 2009)

Sunking said:


> You pull up your vehicle. exit it and go inside to a safe area. Then an attendant pulls the car up on a steel platform (ground plane), The attendant connects the vehicle to the charging apparatus, which will have to be standardized to say 480 or 600 volt 3-phase. When charge is complete, the customer pays, the attendant disconnects, and pulls the car to the waiting area. Off you go 10 to 15 minutes later.
> 
> Basically to make it work the electric station will be a 69 KV or higher substation, depending on how many charge stations that can be operational at any one time. I mean 20 to 60 Kwh in 10 to 20 minutes is one hell of a lot load multiply that by 4 charge stations at one time and WOW.


Not exactly the K.I.S.S. method. Sounds cheap too.

Sorry Bowser330. I am taking business classes at night.


----------



## Bowser330 (Jun 15, 2008)

tj4fa said:


> We're so waaaay behind the power curve.


+1, very true...

Another issue I see about the dump charging is having a special contactor which can open up the pack for dump charging...You can't go through your onboard charger if you expect a surge of amps into your pack in 10-15 minutes...

John Wayland dump charges his Whitezombie's onboard batteries with a pack of yellowtops that he brings to the drag strip...so it is very possible, it just needs to be dummy proof...

Sort of like now when you have to know if you have a diesel car or gasoline car, and not swap the fuels..haha...people will have to know if their car has the available "dump charging port" (DCP) and take to a charging station offering DCP services...


----------



## IamIan (Mar 29, 2009)

wenowhavepower said:


> If i have a car (ev or not), my main reason on driving it, would be for speed and convenience.
> 
> Edit: speed as in to get things done faster...
> 
> Stopping to charge (for 1hr+) is not going to work out for lots of people and yes, you could say,use a regular car but then we will never get the EV charging stations etc because no one is buying/building the cars that requires them.


If you want the generator by all means go for it... but... not everyone agrees.

To me there is a very big difference between how long it takes to refuel a vehicle and how much of my time I have to spend refueling the vehicle.

As long as you do not drive more than the 1 charge range from the EV in 1 Day then the only amount of my time I spend is the 5 seconds or so it takes to plug in and unplug the vehicle... doesn't matter if it charges 50 Miles or 300 Miles worth of battery EV range over night... and it doesn't matter if it takes 6 hours or 8 hours ... when it isn't my time being spent ... I am still not spending more than about 5 second a day of my time to fuel the vehicle.

Gasoline tanks like in the Volt can easily take 5 minutes or more to drive out of my way to the gas station ... stand there wasting my time while I have to wait for it to pump the fuel... and then drive away.

Electric charging / fueling every day would take about 30 to 40 minutes of my time on a yearly basis.

Gasoline fueling for just 10 minutes per trip to gas station + Time at the pump to fuel... for just 10 tanks of gas a year is still 100 minutes of my time... which wastes more of my time than the EV charging does... more gasoline just takes longer and longer of my time.

There are Modern EV battery packs that can do 200 or even 300 Miles in 1 charge... which at least for me ... is way more than enough for any 1 day of driving I might do.... Personally I don't do more than 40 Miles in one day all that often.

So for me... up to 200 Miles per day ... which is over 70,000 Miles per year ... is only 30 to 40 minutes of my time with a EV Battery... the generator begins to have a benefit for the longer trips ... when you drive more than 100 Miles in one day ... but that % of the general public that drives more than 100 Miles in one day ... is very small.


----------



## wenowhavepower (Dec 24, 2008)

Correct but people are more concerned about how quickly can i continue driving.
Planning is great but things don't always go according to plan.

EVs need to be ready for those daily back and forth errands. It would totally suck to have your day wasted because you needed to wait a few hours to charge because you used up your 40 mile range and noticed that you forgot something at the store (or some where else).

How about in emergencies? You just plugged in your EV but an emergency came up but now you need to take a cab because your EV is still charging. Yes you could instead use the oil base car but how many people have more than 1 car?

Good battery packs are here but still a bit too much for the regular person.


----------



## Woodsmith (Jun 5, 2008)

wenowhavepower said:


> How about in emergencies? You just plugged in your EV but an emergency came up but now you need to take a cab because your EV is still charging. Yes you could instead use the oil base car but how many people have more than 1 car?


A generator wouldn't really help in this case unless it was big enough to run the car directly. If the batteries are flat then it isn't going anywhere for a while until it has a bit of charge in it whether bu being plugged in or via the generator.
Of course, if the emergency isn't very far then the car doesn't need a full charge to get moving so it wouldn't take that long.
You could take a charger to keep topping up the batteries as you drive to the emergency but then you may not need to if you didn't have the weight of the generator.

I don't know, we could come up with an infinite number of senarios to debate the value of a generator or not.

I'll agree to disagree with you and see if I can plan my life effectively around my EV, when it is running, as I think I may. If not I'll come back and tell you I have a generator!


----------



## wenowhavepower (Dec 24, 2008)

Yeup, but ideally most generators are set-up so always they keep the batteries charged at a certain %

But correct we could come up with infinite scenarios.

To each their own ~_<


----------



## IamIan (Mar 29, 2009)

Woodsmith said:


> I don't know, we could come up with an infinite number of senarios to debate the value of a generator or not.
> 
> I'll agree to disagree with you and see if I can plan my life effectively around my EV, when it is running, as I think I may. If not I'll come back and tell you I have a generator!


I agree.
To each their own.

For me... given current technology today ... the generator only becomes attractive where in one day I want to travel more than 100 Miles... and that happens so rarely that I wouldn't want to drive around every day with something ( 100+ Pounds) I would use so rarely... for the same reason I don't drive around with an inflatable raft in the car or 5 days worth of food and water ... the chances of me needed it are too remote.

And to be fair ... the only EV I have now is an E-Bicycle... the rest is my plans for the hopefully not to distant future.


----------



## gdirwin (Apr 7, 2009)

I have heard of a university project that added a platform onto a hitch, added a very large generator onto the platform, then plugged the charger into this while running... I vaguely recall that the overall "mileage" was very similar to the stock motor...

The nice thing about the platform is you do not need to haul it around all the time...


----------



## azdeltawye (Dec 30, 2008)

Sunking said:


> Well I work in the electric utility industry and we have already concieved electric filling stations, it is a long ways off as the battery technology does not exist yet, but it goes something like this.
> ...
> Basically to make it work the electric station will be a 69 KV or higher substation, depending on how many charge stations that can be operational at any one time. I mean 20 to 60 Kwh in 10 to 20 minutes is one hell of a lot load multiply that by 4 charge stations at one time and WOW.


Actually its not that bad. Delivering 60 kWh of energy in 20 minutes requires a source of 180kW. Multiply that times 4 and you need 720kW. Size a 750kVA or 1000kVA transformer for the charging station and your good to go. No substation needed. Just regular medium voltage distribution. Heck, your typical shopping mall has a transformer that large.

Granted, if you were to have multiple charging stations on the same block then the utility may have to put in a couple new feeders...

BTW I work for a utility as well.


----------



## Sunking (Aug 10, 2009)

PartsMan said:


> Not exactly the K.I.S.S. method. Sounds cheap too.
> 
> Sorry Bowser330. I am taking business classes at night.


Well I understand but at these power and voltage levels, it is just is not safe to let the public do it. It would be like you working on the Utility power lines. You would be killed.


----------



## Sunking (Aug 10, 2009)

azdeltawye said:


> Actually its not that bad. Delivering 60 kWh of energy in 20 minutes requires a source of 180kW. Multiply that times 4 and you need 720kW. Size a 750kVA or 1000kVA transformer for the charging station and your good to go. No substation needed. Just regular medium voltage distribution. Heck, your typical shopping mall has a transformer that large.
> 
> Granted, if you were to have multiple charging stations on the same block then the utility may have to put in a couple new feeders...
> 
> BTW I work for a utility as well.


You could do it with 13.2 distribution, but likely to take dedicated feeders depending on demand of the feeders.


----------



## tj4fa (May 25, 2008)

Sometimes it's not about the cost and the convenience, sometimes it's just doing it.

Kinda like building an EV...


----------



## dtbaker (Jan 5, 2008)

azdeltawye said:


> Delivering 60 kWh of energy in 20 minutes



and what battery would you propose to stuff all that into? over what cables? Even if your traction pack has 2/0 wire, the amps would melt the terminals off and boil the guts..... I don't know of any charger that could handle this kind of load either.....


----------



## Sunking (Aug 10, 2009)

dtbaker said:


> and what battery would you propose to stuff all that into?


Well at a 20 minute charge rate is 3C, which there are already battery chemistries that can handle that high of a rate and even higher. like LiFe4Po




dtbaker said:


> over what cables?


That is a bit of a loaded question that needs framed with voltage and Kwh capacity of the battery stated. For example with a 400 volt battery pack at say 75 Ah (30 Kwh) would require 225 amp charge current. 2/0 flex cable can easily handle 225 amps



dtbaker said:


> Even if your traction pack has 2/0 wire, the amps would melt the terminals off and boil the guts..... I don't know of any charger that could handle this kind of load either.....


In Telecom industry there are hundreds of 10,000 amp 48 volt chargers, so 200 to 500 is no problem. Heck my golf cart solid state controller is 500 amps @ 48 volts. Nothing melted yet.


----------



## dtbaker (Jan 5, 2008)

Sunking said:


> Well at a 20 minute charge rate is 3C, which there are already battery chemistries that can handle that high of a rate and even higher. like LiFe4Po


I'll depend on some other Li experts to chime in, but I don't think you can charge at those rates without killing the pack. The latter part of the charge for sure has to lower amps, which takes longer.





Sunking said:


> In Telecom industry there are hundreds of 10,000 amp 48 volt chargers, so 200 to 500 is no problem. Heck my golf cart solid state controller is 500 amps @ 48 volts. Nothing melted yet.


big difference between the controller output side and the input side. how BIG is a telcom 500amp 48 volt charger? I just am having a hard time accepting that a battery can suck up that kind of current without damage.


----------



## unclematt (May 11, 2008)

I have participated in the thread "building your own series hybrid generator" and the biggest obstacle was finding a generator head that could produce the required amps and volts without weighing as much as an aircraft carrier. My question is simply: if the OEM guys can create such a generator, why not anyone else? What generator head is the volt using? Is it made from unobtanium or something that a DIYer can't/doesn't have access to? TJ and I were looking at generator heads from aviation APU's, but he hasn't been able to test any of the units he has to see if they can produce the required juice. Anyone have any experience with these, or other sources of generator heads that don't weigh 10 tons? Pelase post if you do.


----------



## dragster (Sep 3, 2008)

Hi
Lets try this a different way. The public has seen 100 years of perfecting the gas vehicle it can now go up to 600 miles on one tank of fuel. The EV can go 35 to may be 70 miles and has the batteries in the back seat and trunk. Gm looked at all the records it has on customers and found that most people drive less then 40 miles a day. So they make a plug in that will go 40 miles and they have but joe public says what a minute I need to go 600 miles and you know you can't do that. So put in a generator to extend the miles that you will not use. Way because most people drive less then 40 miles. In sales you need to have a product that customers need so give them a generator and in a few years come out with a new modal for less money with out a generator and it will sell. As for the weight Kohler makes one that weight 193LB three cylinder diesel 240 volt 41.7 amps electric start GPH 1.1------- Kubota makes a one cylinder diesel for sail boats that is light and use about one cup of fuel an hour a friend I know has one. I called them but could not get any info from them. The charger would just plug into the generator this will help if you find yourself in a spot were you can't find a plug.


----------



## IamIan (Mar 29, 2009)

dtbaker said:


> I'll depend on some other Li experts to chime in, but I don't think you can charge at those rates without killing the pack. The latter part of the charge for sure has to lower amps, which takes longer.


For the common Li charging method you are correct ... you reach a CV point where you want to start pulling back on the current in order to do the latter part of the charge cycle... not the only way to do it... but by far the most widely used method.

It also depends on to what % of SoC do you want to charge ... most battery types can take large pulse surges in charging for short periods of time to get a certain % of the SoC... like 60% or 80%... it is when you say you want to 100% fully charged SoC that you can run into some issues trying to do the last 10% to 20% at very fast rates.



dtbaker said:


> I just am having a hard time accepting that a battery can suck up that kind of current without damage.


A wide variety of batteries can suck up that kind of current.

The question is for how long... and what C rate is it for that battery.

Even the modern LiFePO4 cells that can do very large charging pulses can only do it for so long... eventually they still reach that CV part of the charging curve and the % of SoC above that slows down quickly.


----------



## IamIan (Mar 29, 2009)

dragster said:


> Hi
> Lets try this a different way. The public has seen 100 years of perfecting the gas vehicle it can now go up to 600 miles on one tank of fuel. The EV can go 35 to may be 70 miles and has the batteries in the back seat and trunk.


minor correction.
A modern EV goes double that range ... 70 to 150 Miles per charge without loosing the seats or trunk.... the 35 to 70 mile range is about ~10 years or so out of date with what modern EVs can do.



dragster said:


> Gm looked at all the records it has on customers and found that most people drive less then 40 miles a day.


Minor correction.
the U.S. Federal Government in the census department conducted studies and such... they then publicly released the data for everyone including GM to see.



dragster said:


> So they make a plug in that will go 40 miles and they have but joe public says what a minute I need to go 600 miles and you know you can't do that. So put in a generator to extend the miles that you will not use. Way because most people drive less then 40 miles. In sales you need to have a product that customers need so give them a generator and in a few years come out with a new modal for less money with out a generator and it will sell.


100% agree... once people start driving the PHEVs and REEVs they will see first hand that they don't need the generator... and will be much happier to buy the BEV without it built in.



dragster said:


> As for the weight Kohler makes one that weight 193LB three cylinder diesel 240 volt 41.7 amps electric start GPH 1.1-------


240V * 41.7A = ~10kW
~193 Lbs = ~8.7kWh of 100Wh/kg LiFePO4 you do not have.
Which means such a generator does not have a performance benefit over the batteries until you have driven more than ~52 minutes straight.

1.1 Gallons per Hour at 36.6 kwh per gallon = ~40.2 kwh in to get ~10 kwh out = ~25% efficiency... not particularly good... but I have seen worse.



dragster said:


> this will help if you find yourself in a spot were you can't find a plug.


100% agree... just what % of trips will be longer than ~52 minutes in order to not be able to plug it in?... if that % is high enough for someone it might make a good option ... but for the general public is it as very small % of trips... and for me personally it is a very small % of trips.


----------



## TheAtomicAss (Feb 19, 2009)

Bowser330 said:


> Is a genset a good idea right now...yes..why?...there hasnt been enough installation of charging stations....thats why you see me talking about generator options...


The future is NOW.









Anyway, in regards to your generator idea, it's something I've been researching myself, simply for lack of anything better to do. And what I've come up with has been vaguely useful. According to this chart, a 20KW generator consumes about .9 gallons of fuel at half-load, which is 10KW, exactly what I estimate my car will need at 55MPH. This calculates to about 60MPG, on flat ground, which isn't bad. Could be better, though.

The things I haven't given thought to are the costs of purchasing the generator, and any additional drag it might impart, since it would towed.


----------



## TheAtomicAss (Feb 19, 2009)

dtbaker said:


> big difference between the controller output side and the input side. how BIG is a telcom 500amp 48 volt charger? I just am having a hard time accepting that a battery can suck up that kind of current without damage.


I'm thinking a telecom backup battery is going to be larger than a typical tractor trailer, and rated in the MaH range.


----------



## TheSGC (Nov 15, 2007)

I was given a 5.5 KW generator last winter and just got it running. I am planning to make it into a small trailer, add a quiet muffler from a motorcycle and then make a power system to help supplement my EV. 

The real intent of this is to have a portable power source for the Winter months, make some mulah heating up people's homes when the power goes out. Last winter was bad, home towns out for 14 days without power, and someone else had our main generator, so a easily towable gen is in order. 

But I want to make it also be able to supplement the EV traction pack, giving maybe 35-40 AMPs which should help extend my range by 2x in theory since my cruising AMPs is 80 or less. It's going to be a project for this fall that I will get to once I get my new Synkromotive controller and install it, then I will get down to building a PWM charger/controller to limit the current to the batteries, keep the gen from over loading, etc.


----------



## tj4fa (May 25, 2008)

I want my generator setup to either supplement the batteries on a long haul or run the motor directly through the existing EV components.

Here's the stuff I have so far and how I'm thinking of doing it:

http://s117.photobucket.com/albums/o42/jaynethecat/Range%20Extender%20Stuff/

Here's some of the stuff so far:

Either:
-120/208VAC 3ph 400Hz (40KVA @.75pf = 30Kw) Aircraft Generator producing 111A each phase @6000 rpm - Appears Brushless - Weight 80Lbs (meant for Boeing 737)

or:

-120/208VAC 3ph 380-800Hz (35KVA @.85pf = 25Kw) Aircraft Generator (1950's era F-86 Fighter?) Has some Brushes - weight 82.5 lbs.

Using:

-800V/150A Full wave bridge rectifier 

-24Hp Liquid cooled Kawasaki 4 stroke gas engine around 660cc

-A voltage regulator from an Aircraft Power Unit

And how:

I'm hoping to spin the generator head geared up 2 to 1 with gas engine at it's efficient range of 3000rpm to get rated output of the most practical generator head @ 6000 rpm (not sure which one would be best).

Then rectifying the AC to DC with the full wave bridge rectifier.

I'm hoping to regulate the DC to around 160VDC so that I don't overload my 500A 144V Curtis Controller and selectively run the power through my lead acid battery pack (filtering whatever ripple I have at 400Hz) or drive the EV directly through the controller to the DC series wound motor.

Since it will be on a trailer, I will use it only when I need to go on extended trips and use the battery pack around town.

I'm thinking of tying the battery pack to a common busbar where the generator DC output power could be tied in together with a transfer switch or bypassed straight to the motor controller circuit.

My biggest mental challenge is regulating the power. 25-30Kw would propel the GM Volt at 65mph at a slight upward incline according to the GM volt engineer from the GM Volt website entry I read.

Should I use the brushless generator from the 737 or the 1950s era generator head that appears to have two sets of brushes in it? 

Any help or advice would be appreciated.


----------



## unclematt (May 11, 2008)

Now you look at that impressive array of hardware TJ has gotten together and tell me that we can't make a light weight generator of sufficient output to get this job done.


----------



## IamIan (Mar 29, 2009)

unclematt said:


> Now you look at that impressive array of hardware TJ has gotten together and tell me that we can't make a light weight generator of sufficient output to get this job done.


Definitely doable as in a light weight trailer ... but still looks to be in the ~200 Pound range for the system ... which means it will not have a performance benefit until driving for more than ~1 hour trips... below that, it is dead weight.



tj4fa said:


> I want my generator setup to either supplement the batteries on a long haul or run the motor directly through the existing EV components... Since it will be on a trailer, I will use it only when I need to go on extended trips and use the battery pack around town.


100% agree... detachable trailer ... no need to cart around the dead weight when you are not making 1Hr+ trips.



tj4fa said:


> Should I use the brushless generator from the 737 or the 1950s era generator head that appears to have two sets of brushes in it?


Between those two options ... I'd go with the 737 generator ... 2.5 Lbs lighter for the same or more power output is better ... I tend to prefer brush-less over brushed motors and generators ... but brushed types can work just fine. 



tj4fa said:


> My biggest mental challenge is regulating the power.


If the peak V output is bellow the peak Voltage of a 99% SoC battery pack there is no issue... just put them in parallel before the motor controller.

If the peak V is above the 99% SoC Voltage of the battery pack put in a disconnect to turn off the generator when the battery gets up close to full... SoC or Voltage triggered relay to turn off the ICE.

Either way let the battery pack you have do the buffering and voltage limitation for you... parallel connections have to have the same voltage ... so as long as the battery pack voltage is at a safe level for other components like the motor controller you are fine... if the generator tries to drive the voltage above the battery packs voltage ... all it will do is pump current into the battery pack... once the battery pack voltage gets up to a certain point ... turn off the ICE generator.


----------



## ga2500ev (Apr 20, 2008)

wenowhavepower said:


> Correct but people are more concerned about how quickly can i continue driving.
> Planning is great but things don't always go according to plan.


This issue is one of continual debate when it comes to EVs.


> EVs need to be ready for those daily back and forth errands. It would totally suck to have your day wasted because you needed to wait a few hours to charge because you used up your 40 mile range and noticed that you forgot something at the store (or some where else).


Your thinking is why all car manufacturers have gone hybrid. They carry an extra engine and drivetrain "just in case".



> How about in emergencies? You just plugged in your EV but an emergency came up but now you need to take a cab because your EV is still charging. Yes you could instead use the oil base car but how many people have more than 1 car?


You're kidding about the last part, right? I currently have 5 vehicles in my driveway:

My daily driver
My wife's daily driver
My daughter's daily driver (who is now at college without it)
The backup car purchased for a great price
My EV shell on which there's been no movement in months.

Currently there are two drivers in the house.

Your point almost sounds like the question "Can anyone use more than one TV?" or "Can anyone use more than one computer?"

I wouldn't drive my daily driver out of town. I would not have a problem having a road trip vehicle.

The EV is the same way. I'd use it 90% of the time for daily needs. On the occasions where I needed more range, I'd pick a vehicle more appropriate for the task.


> Good battery packs are here but still a bit too much for the regular person.


I presume in cost you mean?

An EV is not an all purpose vehicle. If one were an off roader, one would not take their daily driver off road, and by the same token one would not take their ATV on the highway to work.

An EV is a specialized vehicle. It just happens to be one that can usually take care of well over 80% of the tasks that an ordinary gas vehicle performs. 

But many try to continue to get to 100%. But getting to the 100% is at the expense of the original 80% that was achieved as is. In other words, trying to get a perfect vehicle gets in the way of having a really good one.

BTW the limitation isn't with the EV, though that seems to be the case. The limitation is with the infrastructure to support EVs. If you had a gas vechicle and the nearest gas station were 75 miles away, you'd have a completely different mindset about how you'd manage filling up. But gas vechile owners, including myself, drive along pretty mindlessly because we know that there's a gas station on virtually every corner, and that even if the price is 50 cents a gallon more than we're used to paying, that we can stop, get a few gallons in a couple of minutes and keep it moving.

The fact of the matter is that if an EV infrastructure were in place, that an EV would never even have to bother to stop to refuel. Using induction, energy can be "beamed" to the vehicle while it is moving. The PATH group in California wrote a paper about an experiment using this technology. They had an electric bus run around a track continuously be beeaming power to its batteries. If such stations were built into the interstate system every 10 miles, then an EV could drive coast to coast without ever stopping.

But as long as the mindset that EVs need to be perfect clones of gas vehicles exists, it's going to be tough to move forward with that type of technology.

I found the White Zombie dump charge interesting. With good battery technology, how long does it take to transfer a charge from the station to the car?

An edit after reading more of the thread.

1) Agree with the long range generator/pusher trailer. It's a good combination for long range driving.

2) There's power everywhere. there really just needs to be a higher speed dump option in the short term until a wider range EV infrastructure can be installed.

ga2500ev


----------



## tj4fa (May 25, 2008)

IamIan said:


> ...Between those two options ... I'd go with the 737 generator ... 2.5 Lbs lighter for the same or more power output is better ... I tend to prefer brush-less over brushed motors and generators ... but brushed types can work just fine.
> 
> If the peak V output is bellow the peak Voltage of a 99% SoC battery pack there is no issue... just put them in parallel before the motor controller.
> 
> ...


Thanks for your help IamIan! 

So that means if somehow I could regulate the DC output of the engine/generator to 153 volts (~100% SOC of the battery pak) then I could just plug in anytime and go through the battery pack without frying the batteries or any of the other components of my EV system. Does this sound about right?

And if so, do you have any idea what do you think the best way to regulate the voltage to 153VDC out of the engine/generator? 

I thinking I want to keep the engine about a constant 3000 rpm and the generator spinning at 6000rpm so they are both in their most efficeint ranges. 

I heard of some electronic way of doing the voltage regulation but I'm not that smart to figure how to do it.


----------



## IamIan (Mar 29, 2009)

tj4fa said:


> Thanks for your help IamIan!
> 
> So that means if somehow I could regulate the DC output of the engine/generator to 153 volts (~100% SOC of the battery pak) then I could just plug in anytime and go through the battery pack without frying the batteries or any of the other components of my EV system. Does this sound about right?


Sure... just make sure to check the safe voltage level ... 153V or whatever number works ( including a safety margin ) with the EV components you have.

Then keep a few other things in mind ... that safe voltage number should be the voltage with no load... in many applications a load will effect the effective voltage ... generally the highest voltage is in a no load condition.

Then as your controller tries to pull a load on the battery pack the voltage of the battery pack will sag slightly ... once this sag tries to drop bellow the voltage level of the generator the generator will see more and more of a load on it as more and more current flow to the battery pack... if the generator is not providing enough to keep up... the packs voltage drops ... and the battery acts as an energy buffer until the generator can recharge it.



tj4fa said:


> And if so, do you have any idea what do you think the best way to regulate the voltage to 153VDC out of the engine/generator?
> 
> I thinking I want to keep the engine about a constant 3000 rpm and the generator spinning at 6000rpm so they are both in their most efficeint ranges.
> 
> I heard of some electronic way of doing the voltage regulation but I'm not that smart to figure how to do it.


Remember peak efficiency for Electric generators and ICE engines is not just RPM... other factors can also effect it... including load... temperature... air pressure ... air to fuel ratio ... etc... if you can get the graph of the engine efficiency vs load / RPMs and such ... you could find out what kin of ranges you would have to work with.

If you have set conditions for the generator and the ICE... it makes it a bit harder to do but still doable.

If you go with the AC generator you will have some advantages in this regard... AC generators are different from DC in that the frequency matters... at the same RPMs an AC motor can vary its load / generator action with alterations to the frequency... so it might give ~10% generator action ... or ~80% generator action even while spinning at the same RPM... this is how some HEVs like the Gen-I Insight controlled the regen from the IMA motor that was always spinning at the same RPMs as the ICE... so it could get 0kW of regen at 4,000 RPM ... 5kW of Regen at 4,000 RPMs... or 10kW of Regen at 4,000 RPMs... then after the kW of generator action are determined... then you rectify it.

Out side of AC motor / generator control techniques .... another option is how a Switch mode power supply works... you use a PWM to vary the current to a capacitor... The capacitor acts as a buffer... a feedback circuit allows the PWM to alter its duty cycle to keep the voltage on the capacitor at the level you want... this has to start with the AC motor already rectified to DC.

If you are starting in AC a Transformer could change the voltage ... but a conventional ~30kW transformer might be a bit heavy... you could get a soild state transformer to make it lighter and smaller ... but that would probably increase the cost significantly.

Of course the old school ... very wasteful method of resistive voltage dividers could work... but has heat and wasted energy issues.

A slightly better voltage divider if you know you are using AC is to use capacitors instead of resistors... but still not very efficient... but at least it doesn't have the heat of the resistive voltage divider.

Of course... the Voltage output from the generator will only be able to go above the battery it is connected to up to the kW limit of the generator... so if under a __ kW load the battery pack is already low enough in SoC to not pull it up above your Voltage cut off point ... all that would happen is that the generator and ICE would see a much bigger load... As long as the kW from the generator are not coming into the battery pack beyond the safe level for the battery pack... the battery pack itself will prevent the voltage from going above a certain point... even if the Generator is putting out ~160V itself... if attached to a ~140V battery the batteries voltage goes up as it begins to take a charging current ... but the Voltage at the terminals is just one voltage ... that of the batteries under that charging current... so even if the generator puts out ~200V with no load... a ~140V battery will not read ~200V at the terminals if you attach it to the generator ... the Voltage will go up from its initial ~140V... dV = IR... and such... but the resulting terminal voltage that the controller would see would be in-between the generator no load ... and the battery no charge... be careful with the connection and disconnection ... large arcs and high currents can happen depending on exactly how you are connecting them.

There are of course other options too... but do any of these so far seem like something you might be interested in?... Figured I would ask , before writing too long of a post and making it hard to read.


----------



## tj4fa (May 25, 2008)

Wow  Thanks again IamIan - I'll have to study on all that info for a while.

I do have this info for the engine I have. I guess I was wrong on how many CCs of displacement the engine has. 

For now, I want to do it the simplest way possible with the stuff I have even if that means losing some efficiency. 

Of course I don't want to let the smoke out of any of my components either...that would be bad.


----------



## Bowser330 (Jun 15, 2008)

http://agnimotors.com/95_Series_Performance_Graphs.pdf

Check the last power graph in the PDF file...

Over 90% efficient

26kw from 72V and 400A @4800rpm

Could we mate this to a motorcycle engine and extract 26kw from it?

I plan on making an EV with a 300V nominal (340V max)..Is it possible to transform the 72V 400A into 300V 87A?


----------



## IamIan (Mar 29, 2009)

tj4fa said:


> Wow  Thanks again IamIan - I'll have to study on all that info for a while.
> 
> I do have this info for the engine I have. I guess I was wrong on how many CCs of displacement the engine has.
> 
> ...


The simplest possible... without care to efficiency losses... to use while driving.

Simplest:

Use a Transformer to bring the AC generator voltage down to less than the ~156V you said was your batteries 100% SoC Voltage... then rectify to DC ... but , that would be a big heavy transformer.... or an expensive solid state one.

---------------

Alternative simplest ( if not used while driving ):

Disconnect the other EV components so that the generator is only attached to the main traction battery... as long as the main traction battery can safely take ~20kW charge rate... just turn off the generator at a pre-determined 'safe' Voltage / SoC level... once the battery reaches that point... the connecting and disconnecting of the energized lines might be tricky... and the sudden initial load on the generator might stall it.

-----------------

If you would like any further details about any of those options just ask... there are lots of very and friendly knowledgeable people on this forum.


----------



## IamIan (Mar 29, 2009)

Bowser330 said:


> http://agnimotors.com/95_Series_Performance_Graphs.pdf
> 
> Check the last power graph in the PDF file...
> 
> ...


yes... just regulate it enough.

Given your link... Over 90% efficient between 150 Amps and 400 Amps at 72VDC... 90% efficiency also requires the load torque to be at that time between about 18 and 51 NM... 90% efficiency also requires RPMs to be about ~4,500 also at the same time as the other stuff ... electric motor efficiency is combination of things.

Yes you can convert between voltages ... any voltage to any voltage ... but there is always loss in the conversion ... getting the conversion above 90% efficient will be a challenge in its own right... but if you do get ~90% for the Voltage conversion... that means you might output at most ~23kW from the ~26kW generator being feed by a ICE putting out ~30kW of mechanical power, while consuming about ~100kW of gasoline energy... about ~2.5 Gallons per Hour.


----------



## Bowser330 (Jun 15, 2008)

IamIan said:


> yes... just regulate it enough.
> 
> Given your link... Over 90% efficient between 150 Amps and 400 Amps at 72VDC... 90% efficiency also requires the load torque to be at that time between about 18 and 51 NM... 90% efficiency also requires RPMs to be about ~4,500 also at the same time as the other stuff ... electric motor efficiency is combination of things.
> 
> Yes you can convert between voltages ... any voltage to any voltage ... but there is always loss in the conversion ... getting the conversion above 90% efficient will be a challenge in its own right... but if you do get ~90% for the Voltage conversion... that means you might output at most ~23kW from the ~26kW generator being feed by a ICE putting out ~30kW of mechanical power, while consuming about ~100kW of gasoline energy... about ~2.5 Gallons per Hour.


23kw should be enough to travel 75mph...and if it takes 2.5gallons to go 75 miles, then thats only 30mpg...not bad, but not good...

For those of us not planning on using range extending trailers, we will need to make the two heaviest items, the ICE and the gen-head, easily removable...maybe through the use of some electrical and mechanical quick-disconnects...so we don't add weight we don't use...


----------



## COS (Dec 23, 2008)

tj4fa said:


>


Nice engine but I am looking at these two for a genset....
http://www.uavenginesltd.co.uk/index.php?id=397
*Technical Specification* 
Engine Type
Single rotor Wankel-type spark ignition engine.
Capacity
208 CC chamber size.
Power Output
38bhp (maximum) at 7800 rpm.
Weight
23.5 lbs (10.7 kg) without generator.
Fuel Consumption 
0.57 lb/bhp/hr at maximum power, 0.52 lb/bhp/hr at cruise. 
Vibration Level
Nominally zero radial vibration. (Peak instantaneous torque is 4 times mean.)
Ignition System 
Electronic contact-less magneto. RFI suppressed HT system
Generator
Provision for mounting GEC/Plessey 28 V, or 900 or 1500 watt (alternatives optional)










OR
http://www.uavenginesltd.co.uk/index.php?id=402
*Technical Specification* 
Engine Type
Wankel-type rotary, single rotor engine. 
Capacity
Single rotor - 294 CC 
Power Output
40 BHP at 6000 rpm, Alternatively 51 BHP at 8000 rpm (carburettor) or 60 BHP at 8000 rpm (EFI)
Weight
43 lb (19.5 kg) as illustrated. Installed weight with cooling system and generator is 57.7 lb (24.4 kg) 
Direction of Rotation 
Anti-clockwise (looking at face of prop flange).
Ignition System 
Electronic CD type with magnetic triggering. 12 or 28 volt option. Fully duplicated system firing spark plugs. 
Fuel Type 
Regular grade (min 92 RON) Mogas (lead or unleaded) or AVGAS 100LL
Specific Fuel Consumption
0.50 lb/bhp/hr at 70% cruise = typically 2.0 imp gallon/hr (2.50 US) 0.56 lb/bhp hr at maximum power. 
Vibration 
Nominally zero (+-20cm gm) radial imbalance. Peek-to-mean instantaneous torque fluctuation is 4 approx. 








http://www.uavenginesltd.co.uk/uploads/pics/AR801.jpg

Both are rotary below 400cc and achieve high RPM so you will need to gear/pulley it down.
Attach/mate either one of the above to this..
http://www.bpbsurplus.com/lc/cart.php?target=product&product_id=17366&category_id=352








And you have a light weight genset. The only problem I see is getting a muffler to get it really quiet.
________
LIVE SEXY CAMS


----------



## tj4fa (May 25, 2008)

Nice stuff COS! 

The weight to HP of those engines is really impressive as is the power that your generator head will put out. 



Bowser330 said:


> For those of us not planning on using range extending trailers, we will need to make the two heaviest items, the ICE and the gen-head, easily removable...maybe through the use of some electrical and mechanical quick-disconnects...so we don't add weight we don't use...


Here is a link to one website where they run the smaller OTCounter generator sets through the EV charger to extend range. Perhaps this info may help some of the people who want a truly On-Board generator.

http://www.evconsultinginc.com/articles/hybridizing_dc_system.html


----------



## Bowser330 (Jun 15, 2008)

+1 COS, great find..

How much do those small wankel motors cost?

500$ for that 30kw generator head is amazing...60lbs too...great deal..

Check this out... (mid way down the page)

http://cp_www.tripod.com/rotary/pg08.htm

PATS APU...I emailed them about the pricing...will update...

10kw from what seems to be the size of a lawnmower engine....nice...


----------



## tj4fa (May 25, 2008)

Bowser330 - Those PATS engines on that website look like they run off of JP-4 jet aircraft fuel...

Even around here, the F-15's and Ground equipment are burning JP-8 a newer jet fuel.


----------



## unclematt (May 11, 2008)

Bowser330 said:


> +1 COS, great find..
> 
> How much do those small wankel motors cost?
> 
> ...


You should check out Aixro and their rotary: 48 hp and very light. Its used by the cart folks all the time, and I think it was a little over $5K per motor. Link to a guy who got 65 HP out of this motor here


----------



## Bowser330 (Jun 15, 2008)

unclematt said:


> You should check out Aixro and their rotary: 48 hp and very light. Its used by the cart folks all the time, and I think it was a little over $5K per motor.


5K$? sheesh thats harsh...how much is a used rotary from an Rx7?

tj, haha, oops, didn't notice it said it ran on jet fuel. haha.


----------



## unclematt (May 11, 2008)

Bowser330 said:


> 5K$? sheesh thats harsh...how much is a used rotary from an Rx7?
> 
> tj, haha, oops, didn't notice it said it ran on jet fuel. haha.


Thats going to be close to the price you find for all of these super neato engines. Tj and I went over this in detail before in another thread, but the high cost of the commercially available engines caused me to try to come up with an alternative. Still working on that...


----------



## WarpedOne (Jun 26, 2009)

> You should check out Aixro and their rotary: 48 hp and very light





> 10kw from what seems to be the size of a lawnmower engine....nice...





> 23kw should be enough to travel 75mph


Aren't you all forgetting that you are looking at maximum engine power? You cannot constantly run these engines at their maximum power. They will quickly overheat and fail.

You should look at ICE engines that are meant and built to run at constant power output.


----------



## wenowhavepower (Dec 24, 2008)

> You're kidding about the last part, right? I currently have 5 vehicles in my driveway


Not a lot of people have two cars, yet alone 5 (or could afford having more than one).
It's not about can you, it's about; do you need to.


----------



## SimonRafferty (Apr 13, 2009)

Would it be such a silly idea to have a generator in a trailer for occasional use when you need to travel more than your normal range. When you get there - you can chain it to a lamp post and be fully electric again.

You get nice little generators called APU's - used for starting aircraft. Generally they use a small gas turbine and produce surprisingly large amounts of power.

Si


----------



## PartsMan (Aug 20, 2009)

WarpedOne said:


> Aren't you all forgetting that you are looking at maximum engine power? You cannot constantly run these engines at their maximum power. They will quickly overheat and fail.
> 
> You should look at ICE engines that are meant and built to run at constant power output.


That is what I was thinking. 
Many airplane motors can run all day at full power but with 100+mph wind speeds. Give yourself a few hp for cooling fans at least.


----------



## Renny_D (Apr 21, 2009)

PartsMan said:


> That is what I was thinking.
> Many airplane motors can run all day at full power but with 100+mph wind speeds. Give yourself a few hp for cooling fans at least.


Does it have to be something this big and expensive. I think a volkswagon engine and two, three or even four rewound alternators - I'm thinking the diagrams shown in the alternative regen braking thread - would do the trick. Essentially you bring the rpm up until you achieve the voltage and amperage you need. Wouldn't this be possible? Could possibly even have a long cable throttle and manage this from inside the car. A trailer kit can be had from Harbor freight for like 300 bucks or cheaper if you can weld one yourself. Seems like it should not be that big of a deal. 

Thanks
Renny


----------



## PhantomPholly (Aug 20, 2008)

Axial Vector has an interesting 200kW genset. I've been watching them for a few decades as a possible aircraft engine.

The more interesting bit is that they have an 8" x 1.5" version of their motor which produces 5hp. That's inches, not feet.

Like so many things, they don't appear to be in mass production.



But, for weight? 10hp is enough for many vehicles for unlimited range. Forget the batteries, just add a huge bank of super-caps!


----------



## caspar21 (Apr 8, 2009)

my needs are hi.. i have a hyway commute of over 100km(60miles) each way.

every battery configuration i look at is either 200ah+ or 4000lbs.

a genset under the hood might do it for me.
Whr/mile on the hyway is probably going to be 2x city speeds.

So if my city Whr/mile is around 250 then 500+ for hyway is a reasonable guess?

Is a 2kw gen gonna be enough? i can get the current requirements from a 50ahr LifePo(4?) pack. and the smaller size allows both space and weight for a genset.


----------



## IamIan (Mar 29, 2009)

caspar21 said:


> my needs are hi.. i have a hyway commute of over 100km(60miles) each way.
> 
> every battery configuration i look at is either 200ah+ or 4000lbs.
> 
> ...


250Wh / Mile at 60MPH = 15kwh per hour = ~15kwh to travel 60 miles.
Requires 15+ kW generator to sustain travel.
100wh/kg LiFePO4 weighs ~150kg or ~330Lbs for ~60 mile trip.
100Wh/kg LiFePO4 weighs ~300kg or ~660Lbs for ~120 mile trip.

500Wh / Mile at 60MPH = 30kwh per hour = 30kwh to travel 60 miles.
Requires 30+ kW generator to sustain travel.
100wh/kg LiFePO4 weighs ~300kg or ~660Lbs for ~60 mile trip.
100Wh/kg LiFePO4 weighs ~600kg or ~1,320Lbs for ~120 mile trip.

You may want to increase the amount to include a safety buffer.


----------



## lkcl (Sep 16, 2011)

The new upcoming Opel Ampera has an on-board generator. After the batteries are flattened (between 40 and 80km), the generator kicks in, and you get a whopping 235mpg out of it. read the FAQ for their estimates (they put it in hectares per potato l/100km so you have to convert 1.2l/100km into mpg).

http://www.opel-ampera.com/

[update: this is a re-badge of the chevvy "volt". http://en.wikipedia.org/wiki/Chevrolet_Volt - which shows that noo, it's not 235mpg, it's actually 35mpg out of the engine (alone) and they're cheating with that figure!]


----------



## Ziggythewiz (May 16, 2010)

Haha. I was about to reply and say that sounds like the Volt specs (assuming 95% of driving is all electric, we get great MPG! Oh, and electricity is free by the way) and when it refreshed it had your update.


----------



## lkcl (Sep 16, 2011)

Ziggythewiz said:


> Haha. I was about to reply and say that sounds like the Volt specs (assuming 95% of driving is all electric, we get great MPG! Oh, and electricity is free by the way) and when it refreshed it had your update.


yes, sorree ziggy  riiight. electricity is freee mmm. btw - look up the RiverSimple vehicle:
http://en.wikipedia.org/wiki/Riversimple_Urban_Car

and some of the links at the end of this:
http://lkcl.net/hybrid_electric_vehicle/design_principle.html

people _have_ done generators-inna-car, proper-like. a geezer called "dave" did one got 'imself 72mpg:
http://www.motherearthnews.com/Green-Transportation/1979-07-01/Electric-Car-Conversion.aspx


----------



## gor (Nov 25, 2009)

10-20 kw per hour at 60 mph- or 10-20 kwh batt.bank in 1 hour ....

here nice links:
http://www.diyelectriccar.com/forums/showthread.php/yes-another-ev-calculator-45278.html
or VehicleEfficiencies calc. from *Spreadsheet to Compare Donor Cars* thread
http://www.diyelectriccar.com/forums/showthread.php/spreadsheet-compare-donor-cars-52097p3.html









thanks for the link -http://www.evconsultinginc.com/articles/hybridizing_dc_system.html








also good research - plug-in hybr. project, apu (pdf)


----------



## DC Braveheart (Oct 12, 2008)

lkcl said:


> The new upcoming Opel Ampera has an on-board generator. After the batteries are flattened (between 40 and 80km), the generator kicks in, and you get a whopping 235mpg out of it. read the FAQ for their estimates (they put it in hectares per potato l/100km so you have to convert 1.2l/100km into mpg).
> 
> http://www.opel-ampera.com/
> 
> [update: this is a re-badge of the chevvy "volt". http://en.wikipedia.org/wiki/Chevrolet_Volt - which shows that noo, it's not 235mpg, it's actually 35mpg out of the engine (alone) and they're cheating with that figure!]


Yes - what you missed was that they said:

"Fuel Consumption / CO2 emissions* according to UN ECE R101
(weighted, combined):


1.2 l/100km* (preliminary information)
27g CO2/km* (preliminary information)"
The important part is the WEIGHTED, COMBINED ... they are including to 40-80km you get on battery power (at 0l/100kh) in that figure ... and not telling you how far they want on gas to get that number (not very far I suspect).


----------



## lkcl (Sep 16, 2011)

gor said:


> 10-20 kw per hour at 60 mph- or 10-20 kwh batt.bank in 1 hour ....
> 
> here nice links:
> http://www.diyelectriccar.com/forums/showthread.php/yes-another-ev-calculator-45278.html
> ...


 ah, good one! amazing - that link forced me, as a free software developer who always said that i would never put office-style applications onto my computer, to put an office-style application onto my computer... i'm glad i did, because it has some really useful data.

ok, so: that spreadsheet basically provides the answer, that whilst _some_ people have added on-board generators (dave's 1970s opel), to add it to a mass-compounded ICE-designed vehicle is just... pretty pointless. both rolling resistance (due to weight, especially on hills) as well as drag put you into a position where you'd need a 200kg+ £4000+ generator, and the fuel economy of such behemoths is well below the point where it's worthwhile doing.

BUT that does NOT rule out the possibility of putting an affordable generator into a LIGHTWEIGHT vehicle, especially one that was mass-decompounded and generally designed around EV principles from the ground up: you'd then get the incredible benefits of a fuel-efficient design

for example, the Mute Car and the RiverSimple Car.

http://www.mute-automobile.de/en/home.html

http://en.wikipedia.org/wiki/Riversimple_Urban_Car

it's interesting to note that Riversimple have concluded that a 6kW on-board power generator is required to maintain a 400kg vehicle (plus passengers @ 80kg ea) at 50mph.


----------



## gor (Nov 25, 2009)

btw: rE-volt by Ben Nelson (e-metro + genset; build thread): http://ecomodder.com/forum/showthread.php/diy-volt-hybrid-open-revolt-style-13809-9.html
e-trike + honda genset:
http://www.youtube.com/watch?v=PJDNWcnYlFo


----------



## gor (Nov 25, 2009)

well, 5kw genset can help on city cycle (if ave. power consumption <= 5kw) 
but on highway, 60 mph - 15 kw constant power consunption for hours - its 15 kw/h power suply, hard to cheat that : ))))) 
basicaly 15 kw (18hp) - lawnmower engine can take care of const. speed for many hours; accel - EV batt and motor

1h 60mph trip - 15 kwh batt bank, 100%dod
100wh/kg lithium - 15kwh batt. bank -150 kg (330 lbs) 
2h 60 mph trip - 300 kg (660 lbs) batt bank empty
kohler 17kw ice- 41kg (90 lb) - 17kw * xx (any) hours

28 hp lawnmower engine (continuose, constant output power) -
you can lift and hold in your hands


kohler industrial 
CommandPROCV23
MaxPower @3600RPMhp (kW) 23 (17.2) Displacementcuin (cc) 41.1 (674) 
PeakTorque @ Maximumlbsft (Nm) 40.2 (54.5) 
Dry *Weight 90 lbs (41kg) *

-----------
basicaly if we use ice for continuouse power consumption in highway speeds - it culd be simple as "direct" drive *ice-assist EV* (opposite to electric assist (electric supercharger) in ice car) - and we got unlimited range EV : ))))
p.s. if weight of such extender about weight of not very big lady or big dog - i can go with that ... : ))))


----------



## lkcl (Sep 16, 2011)

gor said:


> btw: rE-volt by Ben Nelson (e-metro + genset; build thread): http://ecomodder.com/forum/showthread.php/diy-volt-hybrid-open-revolt-style-13809-9.html
> e-trike + honda genset:


gor, thank you, that's hilarous  the guy says it really loud, bless 'im. ok, i looked around, got a bit side-tracked, then ended up here:
http://300mpg.org/projects/evcycle/comment-page-1/#comment-1371

one guy, patrick, asked if it was possible to put an on-board generator into a motorbike, so i couldn't resist using that excellent spreadsheet to do a quick evaluation. i can't... if this is correct, i'm going to get really really pissed off, because we're being forced to drive round in cars that oo, gosh, do 50mpg in the UK and that's like, *really good*, and in the USA if you've got a car that does 30mpg that's like absolutely amazing, and the maths below gives a figure i'm not really comfortable with. PLEASE - really - CHECK it.


Patrick, hi: read the recent posts, here:
http://www.diyelectriccar.com/forums/showthread.php?t=35557&goto=newpost

and see this, for inspiration (and a bit of a laugh):
http://ecomodder.com/forum/showthread.php/diy-volt-hybrid-open-revolt-style-13809-9.html

as long as you can get yourself a low-cost on-board "generator" of some description, you can bridge-rectify a 110v generator as long as the battery is about 96v (no less), or, safer (if you are not an electrical engineer) just get yourself a standard off-the-shelf battery charger (beefy one).

on a motorbike, you really do not need that much power in the first place, so therefore you really do not need a particularly large on-board generator. use the spreadsheet referenced at the 1st link i sent you to do some guideline calculations: for a motorbike you'd probably get away with a 1kW on-board generator to sustain 50mph. this is a good thing, because you need to work out where to put it!

but yes: don't be surprised if the numbers, using that spreadsheet, as well as the fuel usage figures on an average 1kW 240/110 generator, give you something in excess of ... dear holy fucking shit - 550mpg???

somebody for god's sake check this - i'm having difficulty believing it.

take the figures from here:
http://www.genpoweruk.co.uk/Hyundai..._The_ideal_lightweight_camping_generator.html

this is a 13kg generator of dimensions: 490mm x 275mm x 415mm that uses 420g of fuel per kilowatt per hour. divide by 4.6, that means it uses 0.0913 gallons of fuel to generate 1 kilowatt of electricity, in one hour.

now, i couldn't help but plug the numbers into that spreadsheet, but here's the data:

Make Model Year Cd Area (ft^2) Area m^2 CdA ft^2 CdA m^2 Curb Lbs Curb Kg Trans Drive Doors Seats Ft-Lbs Horsepower Aerodynamic Drag KW Rolling Resistance KW Gravity Drag KW KW to Maintain Speed Miles at Speed Wh / Mile MotorCycle Generic 1995 – 0.19 4.0 0.3716 0.76 0.07 300 136 single ratio rwd 1 2 6 0.47 0.35 0.00 1.03 389 21 

so, rewriting that as non-garbage: i assumed a weight of 136kg, i assumed a rolling resistance figure of 0.007 (assuming bike tyres are really good), a drag coefficient of 0.19 (assuming that bikes are really aerodynamically efficient), i assumed a frontal surface area of 4sq.ft (0.37sq.m) and let the spreadsheet do its work @ 50mph - it came up, coincidentally (honest!) with a figure of 1.02kW required.

so, that's 1kW required to sustain 50mph.

so, take the fuel used (0.0913 gallons per kw per hour), take that 50mph figure, and you get 50/.0913 = 547mpg.

five hundred and forty seven miles per gallon.

now, here's the thing: by putting in that little generator in, you don't need a whopping great battery pack. you can get away with a much smaller one - enough to sustain acceleration to top speed RiverSimple's wikipedia page introduces the concept: http://en.wikipedia.org/wiki/Riversimple_Urban_Car#Decoupling_acceleration_and_cruise_demands

so, here's what i don't know: can you fit a generator size 490mm x 275mm x 415mm and weighing 13kg into a suitable bike, and did i get the weight numbers even roughly right? or is that 136kg weight (of the bike, minus its old engine and transmission, plus its new generator, new electric motor) hopelessly unrealistic? bear in mind that the spreadsheet assumes (and includes) a single 90kg passenger *in addition* to that 136kg vehicle weight.

l.


----------



## gor (Nov 25, 2009)

I., that's the numbers i have on bikes cd and cda

basically, their cd- very bad, but area - very low
weight influences acceleration, and not much power consumption on constant speed like air resistance, which is not much on 30 mph, bigger on 50, and a lot on 90
you can maintain 25 mph on a bike with not very much effort - and how much HP (kw) do you have? : )))
usually for a bike 3-5 hp for 50-60 mph
but anyway, accel. is a major power "consumptor", not maintaining constant speed (otherwise we all would run on cars with 18 hp lawnmower engines) : )))


----------



## Jozzer (Mar 29, 2009)

You'd have trouble doing 30mph on a pushbike with only 1kw of power.
My figures for real life motorbikes at 60mph are more like 6-10KW, but that's without having a 6-10kw gennie strapped onboard If you look up fuel consumption on a gennie that size the sums don't look so good..

To be road legal, it would probably have to pass emissions/noise tests too, which would probably lower the efficiency ratings to the same as a regular ICE motorcycle engine..


----------



## Ziggythewiz (May 16, 2010)

First of all...a 28 hp lawnmower motor is not something you can hold in your hands. The biggest mower I ever used was an 8.3, and it was a beast. A 28 hp is a riding mower.

Secondly, scooters and bikes have very high mpgs to begin with because they're so small. That's why most overpopulated countries are run amuck with them; cheap to buy, cheap to drive. 100 mpg is typical for a scooter. Could electric be more efficient? Duh. Is it worth it? Wouldn't be to me. If I were spending $3/week on gas I'd never bother converting to electric, but when I can drive a car for the same price, sure!


----------



## gor (Nov 25, 2009)

Ziggythewiz said:


> First of all...a 28 hp lawnmower motor is not something you can hold in your hands. The biggest mower I ever used was an 8.3, and it was a beast. A 28 hp is a riding mower.
> ...


first of all, it something what i am or everyone do when replacing 700cc engine on the lawnmower - riding or ztr - but still a lawnmower (and i did had replaced a several engines and not just you can (have to) hold it in your hands, but to carry around as well : )))) 
second of all - ...a beast? ... well, 28 hp for 60''deck 15mph mower - a rather underpowered "beast" (suck on the hills and thick grass); 32-40 hp - much better choice (if it's ever enough: )))


----------



## lkcl (Sep 16, 2011)

Jozzer said:


> You'd have trouble doing 30mph on a pushbike with only 1kw of power.
> My figures for real life motorbikes at 60mph are more like 6-10KW, but that's without having a 6-10kw gennie strapped onboard If you look up fuel consumption on a gennie that size the sums don't look so good..
> 
> To be road legal, it would probably have to pass emissions/noise tests too, which would probably lower the efficiency ratings to the same as a regular ICE motorcycle engine..


 awwwWww! no.. wait... that 1kW generator, it's for use around people / homes, it's only 200cc or thereabouts, and it's "sanitised". i.e. EU-regulated for noise. i.e. it's tiny, it's only 3000RPM, and it's surrounded by shielding. don't know about emissions, but i would be terribly surprised if a 200cc engine was dropping even 100g/hr of CO2 into the atmosphere.

yes, if you try to aim for 60mph and your efficiency is so low you have to use 6-10kW, you've absolutely had it. apart from anything else, the cost of 10kW generators blows the exercise out the water!

but, 50mph? looks like the spreadsheet says "no problem". i guess picking conservative numbers would give something like 40mph... yeah, funnily enough, it does. drop in a 0.45 drag coefficient, cross-section of 3ft, then drop the speed to 40mph, the required power comes out at 0.9kW.

i'd say 40mph was perfectly acceptable on a motorbike for commuting. the original poster actually had to drive through 25mph speed limits for the majority of the journey.

so if, as you say, you "have trouble with 30mph on a push-bike with 1kW" then there's something wrong with the spreadsheet. i used to do 30mph on my "push-bike", and that was with my feet strapped to the pedals with those fancy-looking shoes. ok, i was 24 at the time, and i used to run slicks, which kiinda made a difference 

l.


----------



## ken will (Dec 19, 2009)

200cc doesn't sound like much.

Although most new 200 cc motorcycles will do 75 mph.

In 1956 H.Muller set a record of 121.700 mph at Bonneville on a* 50 cc *motorcycle.


----------



## Jozzer (Mar 29, 2009)

I'm going by real life figures for an efficient and light motorcycle here..
At 30MPH 75wh/mile is hard to achieve, meaning youd need a 2.5KW gennie (not including inefficiencies) just to 30.
A quick look online shows a 1kw gennie to weigh in at 14KG dry, and sized at 400x235x400. This is the same weight as 2KW/H of Lipo (1/3 my current pack) and the same size as an 8KW/H pack (ie, it takes up more space than all the cells on my bike).

A 6KW gennie, which would be much more useful, and could recharge my bike in an hour to give me true potential for unlimited mileage (except for petrol storage of course), weighs 85KG, and is actually nearly the same size as the pack I use in my car! (over 15KW/H of battery space).

You must remember that you need the generator too, this will be bigger than your EV drive motor, despite being rated to much less power, and possibly youd need a charger too that is powerful enough to handle the full gennie output.

Now, on my nice light (120kg) 25KW motorcycle with a 6KW pack of LiPo, I don't even have room to fit a couple of 500w PSU's to act as chargers...

Now, 200CC motorcycles can certainly do 70mph, but the engine and gearbox required to make this happen take up all the space in the motorcycle.

SO, that should answer the question as to "why are there no on board generators", at least not often (I do know of a chap with a 6KW/H biodiesel gennie in the back of his Berlingo Van).


Now, 200CC motorcycles can certainly do 70mph, but the engine and gearbox required to make this happen take up all the space in the motorcycle..


----------



## notailpipe (May 25, 2010)

Haven't read the whole thread, just wanted to put my opinions out there.

Honestly, I think DIYEV as a whole is too anti-range extending. Sure, we all want to wean our countries off gas as a whole, that's largely why most of us (myself included) are building an EV and not just lurking on here. But _wean_ is the perfect word for it. I live in America so I'll just speak for us and you can apply your own country to this thought... American's are just not ready yet for the EV. Honestly, they're not. Some are, and there's a lot of hype over the Volt and the Leaf. But your average car here is still a gas car, by far, and will be for a long time. People are not ready to give up the possibility, myself included, on taking a road trip up to the mountains. Or those on the coast, out to the beach an hour or two away. I've spoke about this before and it's still true. Because of that, families will need TWO cars, one for their trips. Our country is just too large.

So, let's say best-case scenario and 100% of families have, of their two cars they need, one EV and one gasser. Well, they're not going to carpool in the EV on Monday through Friday... they're going to use both cars. It would be better if they had maybe one EV and one range-extended EV, and that way during the week they're not using any gas. Of course, that technology is being pioneered right now by Chevy and possibly other car manufacturers. But instead of helping to pioneer this technology and thus eventually wean America off gas, instead most of the EV community is acting pious and has their head stuck in the sand. What will be the result of that? The EV will not catch on. People will continue feeling range anxiety and will say forget the whole thing. In the end, EV could miss its chance and then we'll regret it.

So I say, instead of being opposed because range-extended EVs use gas, it's still a win. Perhaps some DIYer right here will come up with the next big idea to get those to 200MPG or something. But we need to have open minds and view range-extended EVs as what they are: a stepping stone to being gas-free. It's not going to happen suddenly and certainly not for decades, so people need to get realistic about this.

Okay, getting off my soapbox now. 

For the record, I am considering for my next project, working on this very thing. 

Best,
Notailpipe


----------



## Ziggythewiz (May 16, 2010)

notailpipe said:


> families will need TWO cars, one for their trips.


I agree. Everyone around me has 3 or 4, and it's not the nicest neighborhood. There's no good reason most Americans couldn't replace 1 or 2 of their fleet with an EV for commuting.

My main issue with range extending or even with long range EVs is just the economics. To get your money's worth from batteries you need to be using most of your range most of the time. If an EV has a range of 300 miles, but usually sees 30, that's $25k wasted most of the time. That same $25k could could be a hybrid for roadtrips.

Specialization is the key to efficiency. When you add the weight of EV and complexity of EV and ICE systems together, the mileage won't be great for either, and the maintenence costs will go up. I'd love to see a 30 mile EV sold for $15k. Buy that and a Cruze and you have a Volt for the same cost, but serving 2 drivers.


----------



## Bowser330 (Jun 15, 2008)

notailpipe said:


> Haven't read the whole thread, just wanted to put my opinions out there.
> 
> Honestly, I think DIYEV as a whole is too anti-range extending. Sure, we all want to wean our countries off gas as a whole, that's largely why most of us (myself included) are building an EV and not just lurking on here. But _wean_ is the perfect word for it. I live in America so I'll just speak for us and you can apply your own country to this thought... American's are just not ready yet for the EV. Honestly, they're not. Some are, and there's a lot of hype over the Volt and the Leaf. But your average car here is still a gas car, by far, and will be for a long time. People are not ready to give up the possibility, myself included, on taking a road trip up to the mountains. Or those on the coast, out to the beach an hour or two away. I've spoke about this before and it's still true. Because of that, families will need TWO cars, one for their trips. Our country is just too large.
> 
> ...


+1000, ^ what he said...


----------



## notailpipe (May 25, 2010)

I think the economics actually works in favor of the range-extended. 

Consider this:

The Leaf has a range of 100miles, as advertised. I realize most people never get this, but let's just say they do for arguments sake. GM found that most people in the U.S. drive 40 miles or less per day - hence the Volt's range before the ICE kicks on. That means for the majority of the populace, 60% of their pack is unnecessary. Think about that. That's huge! Since the batteries are a major cost, saving 60% here will take a big dent out of the cost. By replacing a bunch of extra battery with affordable ICE technology, you bring costs down and thus introduce "greener" cars to the masses.

Every new field is far overpriced, no exception for the Volt, because they are offsetting the research costs. If the DIY community embraced these more and could set examples of their findings, that would help bring down the cost as well.


----------



## lkcl (Sep 16, 2011)

Ziggythewiz said:


> I agree. Everyone around me has 3 or 4, and it's not the nicest neighborhood. There's no good reason most Americans couldn't replace 1 or 2 of their fleet with an EV for commuting.
> 
> My main issue with range extending or even with long range EVs is just the economics. To get your money's worth from batteries you need to be using most of your range most of the time. If an EV has a range of 300 miles, but usually sees 30, that's $25k wasted most of the time. That same $25k could could be a hybrid for roadtrips.


ziggy,

just from the numbers on battery costs alone, i can deduce that you're still thinking in terms of a 1500kg to 2500kg vehicle, which is completely impractical for an on-board-generator aka "range extended" vehicle. that kind of weight - use the spreadsheet to work out the power required (which you no doubt know already, from experience), then look up the cost of an equivalent diesel generator. it comes out at over 250kg and over $15k _just_ for the generator, doesn't it?

you just... can't do that, and that really is the end of the matter.

to be anywhere realistically affordable and economical, you *have* to cut the vehicle weight down to under 550kg (including passengers). that's the sort of weight where that spreadsheet shows that you can get away with a 4 to 6kW "range extender" dash decoupling-drive-train dash on-board-generator.

it also means you can get away with a vastly-reduced battery size: about 50kg (of 7of 12v @ 24Ah) lead-acid batteries would be more than enough, total cost about £400 to 500, and that's the kind of cost which can be considered to be a "disposable item". so they get destroyed by over-charging, within a year, so bloody what! go take them down the scrap merchant, get £40 for them, go buy some beer or a slap-up meal with that, happy in the knowledge that the lead gets recycled!

ok, it'd be nice to have more complex electronics doing individual bypass-charging - there's even a company that my friend knows of which has a patent on individual plate-charging (inside the battery) to protect them from overload. it's cheap in terms of electronics, involving nothing more costly than a MOSFET and a Diode (per plate).

but right now, the prospect of burning out only a 24Ah cell because you're *not* lugging around a 1500kg-2500kg vehicle, is palatable. whereas, you're definitely right that the prospect of burning out let alone lugging around $25k of rare earth metals beggars belief.

btw there's another concept car out: http://www.gizmag.com/vauxhall-ev-concept/19773/

which, HURRAH! vauxhall / opel say that it is actually "affordable". if only they'd put a damn generator on-board, they'd have something utterly utterly amazing.

l.


----------



## lkcl (Sep 16, 2011)

lkcl said:


> over-charging, within a year, so bloody what! go take them down the scrap merchant, get £40 for them, go buy some beer or a slap-up meal with that, happy in the knowledge that the lead gets recycled!


ok, maybe just £20  a 24Ah battery isn't much, you'd probably get £3 a battery down at the scrap merchants in the UK, for lead.


----------



## lkcl (Sep 16, 2011)

notailpipe said:


> Haven't read the whole thread, just wanted to put my opinions out there.
> 
> Honestly, I think DIYEV as a whole is too anti-range extending. Sure, we all want to wean our countries off gas as a whole, that's largely why most of us (myself included) are building an EV and not just lurking on here.
> 
> ...


damn well said, mr no-to-the-tailpipe 

so, question for you: you know that range-extended EVs have to be low weight, to be acceptable, but the concept of low-weight vehicles in the USA (and everywhere but the 3rd world for that matter) is a joke, to the large manufacturers.

would you be interested to put together something that can be built by a garage mechanic or anyone with a welder, and actually fully documenting the process? i'm talking about a simple kit car - a box on wheels - and sourcing appropriate donor suspension / steering components.

(ok, probably start a new topic for this if you're interested)

here in the UK, the most appropriate donor vehicle has to be a fiat seicento / cinquecento - you can get a smashed-up one of those for about £250. rip off its steering and front-suspension components, people can sell the rest in parts on ebay and get their £250 back: engines go for at least £70 and so do the gearboxes.

what would be an appropriate donor vehicle in the USA to source steering and suspension arms etc? a Geo Metro? i'm thinking along the lines of two sets of kits.

also, very very important bit of the puzzle! i've found a company in China who have a 2-speed Transaxle, rated up to 500kg. gear ratios are 1.5:1 and 4.8:1 which means you can get up hills, duh, but top speed isn't 8mph! 

the only question they haven't answered is: what happens if you go 50mph on this axle, bless 'em. they've only tested it up to 50kph.

it is only about $200 however - for a complete axle with built-in differential, drum brakes, hubs and so on.

but i tell you, these kinds of parts are damn hard to find - even finding that transaxle took me several hours!

l.


----------



## ken will (Dec 19, 2009)

lkcl said:


> also, very very important bit of the puzzle! i've found a company in China who have a 2-speed Transaxle, rated up to 500kg. gear ratios are 1.5:1 and 4.8:1 which means you can get up hills, duh, but top speed isn't 8mph!


Sounds good for a neighborhood vehicle.
And the link to that is .. http://www.?


----------



## lkcl (Sep 16, 2011)

ken will said:


> Sounds good for a neighborhood vehicle.
> And the link to that is .. http://www.?


 ullo ken,

yes, an NEV you'd not have to worry about exceeding the 50kph limit they've got on the things.

ok i found one more - have sent enquiries to these guys, have to wait 48hr round-trip for a response. i've asked them if that's actually a gear-lever on the top.

http://gzdengfeng.en.alibaba.com/pr...rear_axle_assy.html?tracelog=cgsotherproduct1

bless these chinese people, they simply haven't got a clue about writing proper specs for products  i swear some of them use translate.google.com and just shove whatever comes out of that up on the internet.

this is the one i heard back from - waiting to hear if it can cope with 50mph, it is definitely rated for 50 *kilometres* per hour:

http://cqfengchijx.en.alibaba.com/p...ory_Semi_floating_afterburner_rear_axles.html

i think that gearbox ratio difference of 1.5:1 -> 5:1 is about the limit without getting a massive "KERCHUNKK" as you change gear  even with synchromesh gears, if it's too big a difference you *have* to bring the vehicle to a complete stop.

although, i'd be interested, as a software engineer, to experiment with doing electronically-controlled speed-matching: put some switches on the gear-lever, monitoring when it's being shifted, monitor.. achh, this is all too long and off-topic for this thread 

l.

p.s. rambling - get to the point: those back-axles can cope with 500kg easily, and they're about $130 ("Free on Board" - meaning you pay shipping). pffh. tell me a place where you can get a _second hand_ back axle with drum brakes, differential and a 2-speed transmission!


----------



## lkcl (Sep 16, 2011)

ok that cheerful-looking 2-speed $130 FOB Transaxle, they have it going up to 70kph (44mph) with a little petrol engine. kinda sweet, really 

sure it's possible to do a lot better, but probably for a lot more money. i'll keep looking...


----------



## gor (Nov 25, 2009)

i would ditch generator and leave onlye ngine for high speed, el.drivetrain for short trips, fuel economy and combined power 
just add motor or wheelmotor to underpowered car, trike or bike (or opposite - add smaller engine (not for accel, for maintaining speed) toe-bike, ev - and you have ev power for short trips, fueleconomy and unlimitedr ange

there is possible to find some room for both : )))


----------



## gor (Nov 25, 2009)

hybrids should have been plug-ins from the beginning - fuel economy would have been obvious - when prices on gas jumped twice, (and will do it again, matter only of when) people could make short trips without single drop of gas
well, to extend range at highway speed we need or twice bigger battery (to cover losses in controller, motor, drivetrain, etc); or genny to compensate resistance and losses or engine

below spreadsheet - 
resistance for 250cc kawi ninja250r at 57mph: air drag - 4.8hp (3.6kw) ; total (+ rolling+very small 0.06degr.grade - 6.5hp (4.8kw) without drivetrain losses (5-10%) (in dyno data - power at wheels, drivetrain losses included)

for 4.8kw resistance at 57mph: 
battery necessary: 
- to cover controller, motor, drivetrain, extra (wires, etc) efficiency losses: (10+15+5+1=31%); batt should be 145% -7kw; 
at36% losses - batt. 156% - 7.5kw; 
at41%(15+15+10+1)- batt: 165%=8kw; 
at46% - 185%=9kw and 
at50%combined losses - twice the battery (~10kw) 

7-10kw/h lithium at 100wh/kg, 70-100 kg for 1h at 57mph
250cc eng. - 12kw, 43kg (with transmission) - for x hours

so, i would say - drop all the efficiency losses above, drop the geny also, leave the ice
p.s. since engine for maintaining steady speed and el.drivetrain - fo raccel., i'm sure we can get away even with smaller lighter engine & trany. 
who have data on engines and tranys (from donor bikes - weight, power,etc) - please, share


----------



## EVfun (Mar 14, 2010)

The first generation Prius has an electric range of about 6 miles with a top electric only speed of 42 mph. The Honda Insight couldn't even operate electric only because the motor was the engine's flywheel. 

On the plus side, if you ran your Prius out of gas you could still limp to the nearest gas station. I did it a couple of times. The old Dodge Dart couldn't manage that stunt.


----------



## Bowser330 (Jun 15, 2008)

What do you gents think about this setup for a range extender:

3cyl G10 engine found in the Geo Metro or Suzuki Swift
80hp (peak), 175lbs, ~1000$

Agni 95 Motor found here
30hp (peak) 21hp (cont.), 24lbs, ~1600$

I found mpg data and dynos of the G10 1.0L 3cyl engines and found that in generator form it is likely to achieve ~50mpg & ~25hp @ 2500rpm

Summary:

2,600$
16kw continuous
~200lbs
>22 miles+

vs.

2,600$ 
8.3kwh (1$/ahr, 2600*3.2V) 
~ 200lbs
22 Miles+ @ 80% DoD & 300wh/mile assumption


----------



## Anaerin (Feb 4, 2009)

You know, I'm fairly sure it'd be quite easy to take a Mazda wankel engine or an old Comotor one, and couple it to an APU alternator, for a small, light, and efficient range extender. Reasonably cheap, too. And, given the very high speeds wankel engines are good to (9,000-10,000 RPM) as opposed to the lower speeds on piston engines (5,500-6,500 RPM) they would be better for direct driving an alternator or generator. Couple that with a nice high-speed-capable 5-speed transmission to run your car from, and you have a nice slice of your conversion done.


----------



## Bowser330 (Jun 15, 2008)

Right, Wankels are small and light, however I wasn't sure how efficient they are...i'm concerned with efficiency, as I don't want to pollute too much, but I am more concerned with the weight of the APU.

Can you tell me what APU alternator you are talking about that's cheaper and can generate 30hp like the Agni_95?


----------



## lkcl (Sep 16, 2011)

*The new Volkswagon XL1: on-board "generator"*

the new VW XL1 has a maximum fuel economy figure of 430mpg, and a combined mpg figure of 313mpg.

it's achieved through an 800cc TDI two-cylinder diesel engine, connected in parallel to an electric motor (i.e. it's a "Parallel Hybrid", not Series-Hybrid), and has a *seven* speed gearbox.

the vehicle's weight is 795kg, is made of a carbon-fibre resin body on top of a steel/iron chassis, and uses *magnesium* alloy wheels, for lightness.

the drag coefficient is a stunning 0.186, which beats the GM EV1. the styling looks near-identical to that of the EV1 (and the Honda equivalent). there seems to be something about this rather boring but near-teardrop-shaped profile that attracts engineers, probably because of its simplicity.

anyway: the fact that the two motors are in parallel (on separate clutches) means that yes, effectively, this vehicle has an on-board "generator".

one way in which some significant efficiency will have been achieved will be to use a planetary gearbox (same as in automatics, but without the torque converter).

but, overall, this vehicle just emphasises that yes, getting good drivetrain efficiency, low weight, and low rolling resistance and drag coefficients are all absolutely absolutely essential, yet if that's done, then yes you can get staggeringly good fuel economy figures.


----------



## lkcl (Sep 16, 2011)

Bowser330 said:


> What do you gents think about this setup for a range extender:
> 
> 3cyl G10 engine found in the Geo Metro or Suzuki Swift
> 80hp (peak), 175lbs, ~1000$
> ...


the Agni's good, bowser, but the engine's far too heavy. it somewhat defeats the object of the exercise.

agni... agni... oh you mean a Lynch LEMCO motor? yes, they're bloody excellent. superb torque, very low weight, high efficiency.

oh wait... Lynch Motors are DC output, and it's a brushed motor. so, you can't get AC out of it, and you'll get massively-spiked intermittent output as it arcs when the commutators turn. so you'd need to include some rather heavy-duty spike supressors (inductors) that....

yeah, you'd be better off finding a BLDC motor from somewhere.

sorry, bowser, perhaps not what you were expecting to hear: no good, and no good 

l.


----------



## lkcl (Sep 16, 2011)

Anaerin said:


> You know, I'm fairly sure it'd be quite easy to take a Mazda wankel engine or an old Comotor one, and couple it to an APU alternator, for a small, light, and efficient range extender. Reasonably cheap, too. And, given the very high speeds wankel engines are good to (9,000-10,000 RPM) as opposed to the lower speeds on piston engines (5,500-6,500 RPM) they would be better for direct driving an alternator or generator.


i'd be very concerned about running a large electric motor at those kinds of RPM (unless geared down, but again, you lose efficiency by doing so). any large electric motor has to have, by definition, a considerable diameter. you start running that much metal round at 10,000 RPM and you're pretty much guaranteed to have bits flying off.

diesel engines are really the sensible option, because of the enormous torque that they can achieve, even at low RPM.

[update: i just found this fascinating article - http://www.libralato.co.uk/pa_comparison.html which mentions several instances where wankel engines have been used in concept cars. so, looks like you were right - it can be done!]

l.


----------



## lkcl (Sep 16, 2011)

gor said:


> to cover controller, motor, drivetrain, extra (wires, etc) efficiency losses: (10+15+5+1=31%); batt should be 145% -7kw;
> at36% losses - batt. 156% - 7.5kw;
> at41%(15+15+10+1)- batt: 165%=8kw;
> at46% - 185%=9kw and
> at50%combined losses - twice the battery (~10kw)


http://www.fueleconomy.gov/feg/atv.shtml
drivetrain efficiency of ICE vehicles is between 93 and 95% efficient.

motor controllers are about 98% efficient.

motors are about 90% if you get a standard BLDC and 94% if you get an EMRAX or a Printed Motor Works Ltd "Outrunner".

also, you don't *add* the numbers together, you *multiply* them.

wires: if you get half-inch-thick cables, losses are such that you just... get thicker wire! 
http://www.stealth316.com/2-wire-resistance.htm

so if you use 10mm thick cable, the voltage drop is 0.14v: as a ratio of 100v that's negligable and can be ... well, let's not discount it - it's 0.0146%...

so... worst-case figures: .998 * .93 * .9 * .93 = .819 ooooo jammy basturd, that's *just* within that 80% target  but if you use the EMRAX motor, you get 0.855 which is 85.5% drivetrain efficiency. best case: 0.998 *.98 * .94 * .94 = .864: 86.5% drivetrain efficiency.

that's excluding efficiency losses from the generator itself, but again, that's been taken into account already by using the "rated" figures (power of the generator, not power of the motor *running* the generator).

l.


----------



## Bowser330 (Jun 15, 2008)

lkcl said:


> the Agni's good, bowser, but the engine's far too heavy. it somewhat defeats the object of the exercise.
> 
> agni... agni... oh you mean a Lynch LEMCO motor? yes, they're bloody excellent. superb torque, very low weight, high efficiency.
> 
> ...


I am not sure I agree, I dont think 200lbs is much weight at all, did you consider the second part of my post that you did not quote? I dont see how the weight defeats the purpose when the weight of a comparable portion of lithium ion batteries doesn't give you but 22 extra miles, where as the range extender could provide 16kw continuously...

2,600$ from the genset concept
16kw continuous
~200lbs
greater than 22 fuel powered miles

vs.

2,600$ of lithium-ion batteries
8.3kwh (1$/ahr, 2600*3.2V) 
~ 200lbs
22 Miles @ 80% DoD & 300wh/mile assumption


----------



## gsmith191145 (May 1, 2011)

fixityourselfer said:


> Hello everybody.
> 
> I'd like to know why nobody has ever decided to mount a on-board generator to use when battery power drops too low??
> 
> ...


I have an electric vehicle because I do not want to give the oil companies anymore money. 

I am an advocate of solar power. No need for a power plant here. 

My electric car will go the distance that I built it to do. If I require more distance or performance, then I will make the necessary changes to fit what I need.

I went electric and I will stay electric.


----------



## lkcl (Sep 16, 2011)

*Online Vehicle Simulator*

http://www.diyelectriccar.com/forums/showthread.php?p=264363

i converted the maths behind the spreadsheet into python, and then made it a pyjamas (http://pyjs.org) application, if anyone's interested.

l.
http://lkcl.net/ev


----------



## mizlplix (May 1, 2011)

One of the basic laws of thermodynamics is "WHEN Energy changes form, it suffers a loss". (Usually due to heat emissions).

When you drive electric, the batteries power your car, nice and neat.

If you use an ICE to power a generator to power your EV, you have the usual ICE losses plus the heat emissions loss of the generator. (not very efficient)

Then you have the extra loss of hauling around the extra equipment necessary for the ICE motor, fuel tank and the generator system when you are running only on electric.

The most efficient way of utilizing ICE power is to use a "Direct drive" system. A manual transmission/drivetrane. No slippage or torque converter or generator.

If you need an extended range EV, you need a "pusher trailer" type system. There are several out there to Google. They are basically a motor/transmission/unit coupled to your EV with a common trailer ball. It cuts in when you tell it to and pushes you along.

You park it in your driveway when you dont need it. 

A motor/generator is a bad idea both from cost and efficency standpoints.

Miz


----------



## lkcl (Sep 16, 2011)

mizlpix - you make some good points, but the Volkswagon XL1, which has a 313mpg fuel economy figure, proves your conclusion to be just plain wrong. sorry, but that's the facts. if VW managed it, so can anyone else: you just have to be prepared to follow in their footsteps, and the criteria are very very strict.

anyway, i'll go over what you've written (and, coming back to the top of this message after writing, i now see why you have concluded what you have concluded, and i am also not surprised that you have drawn the conclusion that you have - but you have, like many many people, completely missed out the very strict - and acceptable - criteria where this concept of an on-board generator works extremely successfully)



mizlplix said:


> One of the basic laws of thermodynamics is "WHEN Energy changes form, it suffers a loss". (Usually due to heat emissions).


yes. the simplest neatest explanation is carnot's theorem:
http://en.wikipedia.org/wiki/Carnot%27s_theorem_%28thermodynamics%29



> When you drive electric, the batteries power your car, nice and neat.
> 
> If you use an ICE to power a generator to power your EV, you have the usual ICE losses plus the heat emissions loss of the generator.


correct.


> (not very efficient)


incorrect. efficient diesel generators, despite the (correct) losses you state, consume about 0.28 Litres of fuel per kilowatt per hour. such generators have been designed to run at a fixed RPM and under load, which is precisely what's needed.



> Then you have the extra loss of hauling around the extra equipment necessary for the ICE motor, fuel tank and the generator system when you are running only on electric.


yes. keeping that to a minimum sensible size (6kW) the dimensions are about (for an off-the-shelf unit), 600mm x 500mm x 500mm, and the weight you can get away with about 60kg for a petrol version, and 90kg for a diesel one.

if you use the EV calculator, i think you'll find that the "extra loss of hauling around 90kg" when running on ECO Low-Rolling-Resistance tyres will be... ok, let's plug it in: yes, at 60mph that extra 90kg "loses" 200 watts. 0.2kW.

if the generator is 6kW, that 0.2kW works out to be a 3% extra "loss". but, you've just *saved* massively on the weight, by being able to trade a 250kg battery pack for a 50kg one, because you don't need it: you can always continuously charge up the smaller one [note: this is a simplification]

so even without the weight saving of the reduced battery pack, i'd say that was a good trade-off, but actually you *gain* efficiency by simply accepting a different set of design criteria and associated driving conditions [remember i mentioned that "simplification" above?]

then, as long as you can get up to 60mph with that 6kW, if you plug in that figure of 0.28 Litres per Kilowatt per hour, you get... convert .28 to imperial gallons, that's 0.0601 g/kw/h, then multiply by 6kW, that's .365 gallons per hour, 60 / .365 = 164 miles per gallon!

you see how the maths says, quite simply, that you're off-track? plug the numbers into that EV calculator: play with it. i've done an online version, and you can check the source code as well, to make sure it's the same as that EV calculator spreadsheet:

http://lkcl.net/ev/vehicle_simulator/output/Simulator.html

you'll see that it's perfectly reasonable to require only 6kW @ 60mph *if* certain very very strict criteria are met (which the Volkswagon XL1 does, by quite a long way, to give you just one example).



> The most efficient way of utilizing ICE power is to use a "Direct drive" system. A manual transmission/drivetrane. No slippage or torque converter or generator.


yes - this would be absolutely, absolutely fantastic. however, there's a problem. several. let's go through it.


direct-drive motors are, like all electric motors, at their most efficient when running at higher RPMs. at lower RPMs, they're at risk of burn-out if you push them above the rated torque.
the conditions where you need lower RPM and higher torque the most are on steep gradients.
a 25% gradient even with a 550kg vehicle and a wheel radius of 13in (0.3m) requires 550 * 9.81 * 25% * 0.3m = 400Nm of torque
a direct-drive hub motor which can deliver and sustain, per wheel, over 100Nm of torque (just to overcome gravity alone), at its *least* efficient point (low RPM) *without* burning out, needs to be at least 20kW per wheel.
80kW total, just to get up a hill, when operating at the least efficient point of the electric motors, is sheer madness, not to mention the cost of the Motor Controllers required are going to be around five times higher than if you had a simple 15kW single motor instead
according to http://www.fueleconomy.gov/feg/atv.shtml drivetrain losses are about 5% to 7%. that's not as bad as you're making out, and it's definitely way less than operating within the stall-RPM range of a direct-drive hub motor
not only do the four, separate motor controllers cost a fortune, but the cost of 4 direct-drive hub motors which also need to be massively over-powered in order to cope with the worst driving conditions by far and above exceeds the cost of a single motor plus associated gearbox, which would place the retail cost even of a small 350kg vehicle somewhere around the $30k mark.
so, overall, whilst direct-drive hub motors appear, on the face of it, to be absolutely fantastic, they're *only* fantastic under ideal operating conditions. now, whilst it's fine to put a 250 watt hub motor into the wheel of a bicycle and to still expect people to get off and push if the hill *really* gets too steep, that's simply not acceptable for a car.

this explains why Volkswagon's XL1 Concept Car has a *seven* speed gearbox. they went "all out", and made damn sure that (both) engines operate at all times at their highest optimal conditions.




> If you need an extended range EV, you need a "pusher trailer" type system. There are several out there to Google. They are basically a motor/transmission/unit coupled to your EV with a common trailer ball. It cuts in when you tell it to and pushes you along.


just from this, alone, i can tell that you're still thinking in terms of 1.5 to 2.5 tonne vehicles being acceptable as an EV conversion. which is fine, if you accept the mass-cascade-effect and the consequences on your wallet.



> A motor/generator is a bad idea both from cost and efficency standpoints.


wrong on both counts. sorry. i've covered the efficiency perspective, above, and briefly touched... wait.... no, you're correct!

yes, actually, you're correct. a motor/generator is a bad idea both from cost and efficiency standpoints... *if* you're considering to run a standard 1.5 to 2.5 tonne vehicle with a frontal surface area of 2.5 sqm or above and a drag coefficient of over .... well, it doesn't matter what the drag coefficient is when you've got a 2.5sqm front surface area (unless you're sitting in a delta-wing) and rolling resistance losses alone being over 6kW even with "eco" tyres, which would, thanks to the extra weight, cost you a fortune because with the harder compound having to support that extra weight, they'd wear out very very fast.

so you're correct, but the conditions are so ludicrous that i am genuinely not surprised that you have arrived at this conclusion.

it turns out however that by applying "mass decompounding" - i.e. by setting a strict weight limit of around 350kg to 400kg (Neighbourhood Vehicle or EU Category L7e), you don't *need* an ultra-expensive battery pack, or an ultra-expensive motor, or an ultra-expensive motor controller, or an ultra-expensive on-board generator.

you can, in fact, get away with a 15kW electric motor (which is coincidentally the limit of E.U. Category L7e), and, as long as you have a small and light-weight vehicle, with a very good drag coefficient, you can stick below that magic 6kW figure.

look at the statistics on the new Renault Twike (the Category L7e version): it uses 7kW to do 60mph. look up the figures on the Aixam MEGA City car (Category L6e): it uses 4kW does 40mph. those work out (if you use that 0.28l/kw/h figure above) to be around 150mpg!

it *can* be done - you're just, like so many people, still thinking in terms of 1 tonne and above vehicles. even Volkswagon's XL1 is a laden weight of 1 tonne, and _they_ managed 313mpg (with some serious serious R&D money).


----------



## mizlplix (May 1, 2011)

And engineers can prove a bumble bee can not fly.

Until i see more motor/genset cars on the road I stand by my version.

Miz


----------



## lkcl (Sep 16, 2011)

gsmith191145 said:


> I have an electric vehicle because I do not want to give the oil companies anymore money.
> 
> I am an advocate of solar power. No need for a power plant here.
> 
> ...


rock on, mr gsmith! you're extremely lucky, and are showing the way forward. i wish very much that i was in the same position as you've managed to achieve: complete independence.

i hope you won't mind if i show people that there's an intermediate step by which they can transition to the same level of independence that you've achieved.


----------



## lkcl (Sep 16, 2011)

mizlplix said:


> And engineers can prove a bumble bee can not fly.
> 
> Until i see more motor/genset cars on the road I stand by my version.
> 
> Miz


miz... i went to a lot of trouble to write what i did: i didn't have to write it. i think... the best thing for me to say is that you are entitled to believe what you wish to believe, and that you are perfectly entitled to go with the reality that you wish to place in front of your eyes. i wish you the best with your life's chosen path.


----------



## lkcl (Sep 16, 2011)

*Suzuki Swift Hybrid*

http://en.wikipedia.org/wiki/Suzuki_Swift#Plug-in_hybrid

aka the "Geo Metro". this is *exactly* the sort of thing i'm talking about: a "Series Hybrid" which, exactly as i just posted 1 hour ago, has an on-board 660cc Generator to charge up the batteries whilst driving.

fascinating. the statistics are almost exactly the same as the ones that i've been advocating, but it's the vehicle itself that is ever so slightly out of the optimum range. but, sadly, thanks to those cubic and square laws, that's enough.

looking at the EV calculator spreadsheet numbers, you can see what's gone wrong:
* Front Surface Area: 1.8sqm (20sqft)
* Drag Coefficient: .34
* Weight: 822kg (excluding 2 passengers @ 150kg)

assuming a drivetrain efficiency of 80%, the aerodynamic losses @ 60mph are 7.34kW, whilst the rolling resistance losses are 1.79kW thanks to the 1 tonne weight. that's a total of 11.41kW.

assuming that the on-board generator is at the high-efficiency end of 0.28 litres per kilowatt per hour, the fuel used at 60mph works out to be .28 / 4.6 * 11.41 = 0.7 gallons per hour. 60 / 0.7 = 86mpg, which is virtually identical to the figure reported in the above wikipedia page: 88.4mpg combined cycle.

so, actually, they probably managed either better drivetrain efficiency than 80% for the newer model (i picked the Metro 2dr Hatch line in the spreadsheet) or they managed to improve the aerodynamic losses somewhat.

regardless, it still doesn't matter: that cubic law kills you on the aerodynamics, and the square law doesn't help on the rolling resistance.

that's why that guy cut one top half of his geo metro off  he replaced the entire passenger side with a flat sheet of fibreglass, reduced the front surface area by a good 3 sqft! that 15% reduction would be enough to increase the fuel economy figure to 98mpg, for him.

l.


----------



## lkcl (Sep 16, 2011)

mizlplix said:


> And engineers can prove a bumble bee can not fly.
> Miz


bumblebees create a down-draft vortex with one beat of their wings, against which the return stroke has, thanks to the cubic law of aerodynamics, a greater force to work with.

you don't have to "understand" this in order to "copy" it, miz.

you don't have to *know* that it works - you just have to *trust* that it works. that's how i manage to tackle million-line software libre source code, from zero prior knowledge, and get results within two weeks: i don't go "oh i'll wait until someone else explains this to me before i'll believe that i, personally, can tackle it" - hell i don't even wait until *i* understand the code fully before diving in.

i understand completely, however, if you cannot trust. most people do not trust. they want proof: they want to be the last person in the world to make the decision, because they want to see that everyone else made the decision before they went ahead and made the exact same decison. 

you probably guessed already: i don't operate that way. so, i wish you luck with your choice of perspective, and i encourage you to stick with your perspective for as long as you find it useful for you to do so, to see where it leads you, so that you learn the value of choosing your own life perspective.

l.


----------

