# need help with some motor/ propulsion questions



## onegreenev (May 18, 2012)

Chevy Volt comes to mind but in the DIY arena I have not seen any on demand ice generators powering the drive motors to propel the vehicle down the road. 

Pete


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## PStechPaul (May 1, 2012)

I always suggest for people to use my http://enginuitysystems.com/EVCalculator.htm to answer this sort of question. The default values will give you some idea.

A 2200 pound vehicle moving at 62 MPH needs about 50 HP for a 10% slope (or accelerating at 2.2 MPH/sec or 0-66 in 30 sec) or 13 HP on a level road.

You will need to figure out your actual needs as well as know details about your car's transmission and differential ratios and other information for a more accurate estimate. Also know that these figures are for sustained operation under those conditions. Depending on the motor, it may be able to put out at least 2x its rated output and about 5x for short bursts. 

So a 15 HP motor should be considered minimum for a small EV at highway speeds and 50 HP should be adequate with 2-3x short term bursts. Also 50 HP is about right for direct drive, while 15 HP would require a transmission.

As to the size of an on-board generator, without batteries it would need to meet the peak power requirements, so it would need to be at least 10 kW continuous rated. You really should have some large capacitors or a small high-C-rate battery pack to provide higher peak current. I would say enough to provide 50 HP (37 kW) for 10 seconds, or 370 kJ, or 102 Wh. This would be 51 F at 120 VDC and 308 amps. If you can use 20C batteries you could get a 15 Ah or 1.8 kWh pack which would cost about $900-$1800.


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## ga2500ev (Apr 20, 2008)

SYNc said:


> Greeting board, I've got some questions surround motor size/strength to car weight ratio. Is there a rule to use, or some calcs.


I'll leave this one to others for details. Short answer is 8-9 in motors for small vehicles, 11 in and higher for large ones.



> Secondly, I've wondered if it is more efficient to generate electricity on board (via a ICE+gen) and send the power via cables to a rear motor driving the rear wheels (assuming car is rear wheel drive). Is it not more efficient to transport high current via cables for 10 feet, vs going ice-trans-driveshaft-diff-axles with mechanical linkage?


The real question is either more efficient than driving an electric motor with batteries? A ICE starts with an efficiency of 25% and works it way down from there. Battery charge/discharge efficiencies are typically in the 90+% range.

Also in terms of transport, high voltage is always more efficient than high current as losses rise vs. the square of the current.



> I know typical generator sets are plagued by heavy weight, but say the package can be reduced in size/weight, how much output would be necessary to skip the batteries and just generate electricity and power the motor on demand ?


Again the question comes down to why? 
In a hybrid vehicle, the ICE engine runs in its most efficient power band. But the tradeoff is that is doesn't provide peak power to the system, only average power in that most efficient power band. That means that the engine can be smaller, lighter, and more efficient than if it's the only powerplant in the car. In short the ICE engine in a hybrid never "revs" to provide more power. It provides the most efficient power it can at all times, and where there's an excess that is stored in the batteries in the hybrid.

When peak power is needed, the batteries and electric motor provide the extra kick. The deficit is then later made up by the steady energy ICE powerplant.

Without batteries, the vehicle must carry a larger engine to power the genset/electric motor than if there was no genset/electric motor. In addition that without batteries, the engine would have to be able to provide peak power to the vehicle. So therefore any efficiencies you hope to gain by the design are lost at the outset.

The only type of vehicle that uses an engine directly coupled to the electric motor is a diesel electric train. The specific reason that is done is because the electric motors can provide maximum torque exactly when the train needs it most: starting from a dead stop. This is considerable considering that a train can weigh anywhere from 3000 - 20000 tons.

So the question is exactly what is it that you are trying to accomplish? What shortfall are you attempting to correct by adding a genset/electric motor? Why exactly are you trying to ditch the batteries, when in fact the batteries are the reason that all the efficiencies for EVs are created?

I sure would like to know.

ga2500ev


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## dougingraham (Jul 26, 2011)

SYNc said:


> Greeting board, I've got some questions surround motor size/strength to car weight ratio. Is there a rule to use, or some calcs.
> 
> Secondly, I've wondered if it is more efficient to generate electricity on board (via a ICE+gen) and send the power via cables to a rear motor driving the rear wheels (assuming car is rear wheel drive). Is it not more efficient to transport high current via cables for 10 feet, vs going ice-trans-driveshaft-diff-axles with mechanical linkage?
> 
> I know typical generator sets are plagued by heavy weight, but say the package can be reduced in size/weight, how much output would be necessary to skip the batteries and just generate electricity and power the motor on demand ?


Rule of thumb for energy usage is weight in lbs of car / 10 = average wh/mile. Example would be a 2000lb car takes 200 wh/mile. So 200 watts would take you one mile per hour average. 12000 watts would take you 60mph. It is a bit simplistic but gives you a way to do rough estimates. It does not take into account hills and headwinds or excessive stop and go traffic or extremely high speeds.

ICE+generator is not at all efficient. ICE is typically only around 12% efficient at converting the gasoline to mechanical energy. The generator would be perhaps 80% efficient and the motor similar while the transmission and differential might be over 90% efficient. If you have a gasoline engine you are better off driving the wheels directly.

For my conversion I estimated I would need at least a 20kw generator set to maintain 65-70mph for long distance highway travel. This is around 30 hp. And to go up steep grades it would not keep up and would use battery power to maintain speed. This turns into another project of similar level of complexity to the original EV conversion.


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## SYNc (Aug 29, 2013)

ga2500ev said:


> I'll leave this one to others for details. Short answer is 8-9 in motors for small vehicles, 11 in and higher for large ones.
> 
> 
> 
> ...


 easy , 
1. grid power is dirty (power companies around L.A. generally have less than 10% renewable in their portfolio). 
2. batteries are heavy, inefficient, costly, and too bulky. 
3. lithium mining, processing, and transportation seems illogical to the "go green" vision.
4. many companies are now producing lightweight/high-output/ CLEAN gen-sets to be used as Range extenders. 

lotus and fagor have designed both a 2 cyl and 3 cyl engine that weights around 100 lbs and puts out 50kw of power. It runs between 1.5k and 3.5k rpm range.
tested on a prototype hybrid car with the 3-cyl engine they managed 45+ MPG after batteries were depleted. also attaining 120g CO2/KM. 
this part puts to rest the antiquated thinking regarding gen-sets being inefficient, heavy, bulky, and DIRTY. 

another company has built a 900cc 2 cyl that produces 30kw and weighs in at 120lbs complete unit. oh and its emission compliant. 

Ok if batteries are absolutely needed, wouldn't this allow for a minimal battery size?

VIA motors is even doing similar thing with trucks/vans. they hook up a 150kw gen set, and use it to drive the elec motor once batteries are done. 

doesn't chevy volt do something similar? once your batteries hit a preset discharge, ICE+ genset kick in and start sending power to elec motor and excess to battery pack? and if you need a huge deal of power, then via planetary gear the ice produces physical output to drive train.


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## Duncan (Dec 8, 2008)

SYNc said:


> easy ,
> 1. grid power is dirty (power companies around L.A. generally have less than 10% renewable in their portfolio).
> 2. batteries are heavy, inefficient, costly, and too bulky.
> 3. lithium mining, processing, and transportation seems illogical to the "go green" vision.
> ...


_tested on a prototype hybrid car with the 3-cyl engine they managed 45+ MPG after batteries were depleted. also attaining 120g CO2/KM. _
45 MPG ! - and this is considered good for a 3 cyl lotus????

_doesn't chevy volt do something similar?_
Not really - the main power path is motor mechanical power to wheels

Serial Hybrids are very inefficient
The reason why is simple

Fuel - mechanical power - (20% - 25%)
mechanical power to road - 97%
Total efficiency - 19% - 24%

Fuel - mechanical power - (20% - 25%)
Mechanical power - electricity - (85% - 95%)
electricity - mechanical power - (85% - 95%)
mechanical power to road - 97%
Total efficiency - 14% - 22%

You may be able to get a slight increase in engine efficiency but that will be more than cancelled out by the double hit of the motor and generator
This is why all current hybrid cars are effectively parallel with the engine driving the wheels


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## PStechPaul (May 1, 2012)

I wish you would provide links to support your assertions, but I was able to do an on-line search and I came up with this:
http://www.mondragon-corporation.com/ENG/Press-room/articleType/ArticleView/articleId/1558.aspx

If this is correct, their 51 kg naturally aspirated version puts out 35 kW and the 58 kg supercharged version is 50 kW. I find this hard to believe, but if true (and affordable), it may change much of the DIY design standards. With such a lightweight and powerful genset, it would be very easy to carry it along, and EVs could be made with perhaps 5 kWh of batteries for 10-15 mile short hops, and the range extender could be implemented for longer trips. Even if you had to stop every 15 miles to charge, a 35 kW genset would do the job in less than 10 minutes, but of course it would be much better as a series hybrid. An extra 110 pounds is not a problem.

Some other links to check out:
http://www.evdl.org/archive/index.html#nabble-td3546791
http://electrichybridcars.net/lotus-range-extender-range-target
http://www.fagorederlan.es/ENGLISH/...Range-Extender-ecoengine-model-in-Geneva.aspx
http://www.theengineer.co.uk/in-depth/range-extender-engines/1008736.article
http://www.sae.org/mags/SVE/9785

Can't find anywhere to buy one or how much it might cost. Seems to be mostly an OEM item, and I'm surprised we haven't heard more about this since 2011 when most of these articles were written.

Of course, it is much better to use electricity from the grid, and you and anyone else may purchase 100% wind or solar power as I do, so the argument about grid power being dirty is flawed. You just have to exercise your choice as an electric power customer and obtain your electricity from a company such as *Clean Currents*. But a range extender such as this may make an EV conversion more cost effective now, so you can save money by using a small battery pack, and then install a bigger one when costs come down in several years.


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## SYNc (Aug 29, 2013)

Duncan said:


> _tested on a prototype hybrid car with the 3-cyl engine they managed 45+ MPG after batteries were depleted. also attaining 120g CO2/KM. _
> 45 MPG ! - and this is considered good for a 3 cyl lotus????
> 
> _doesn't chevy volt do something similar?_
> ...


considering its nearly 4000 lbs, I'd say yes, that's pretty impressive mpg, considering its only generating electricity. again with that setup they got a 600 mile range after batteries are depleted.

and on a typical ICE, when I'm doing 70-85mph my engine revs are around 2k-3k . looking at my power band, i'm generating 100-150 hp at that rev range, overkill imo.


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## SYNc (Aug 29, 2013)

i didn't provide links , assuming everyone should know about these units by now, the lotus-fagor engine has already been proven in several prototype vehicles, and ive read that future range rover models will be incorporating this unit. lotus has actually created 2 variants . they have a 2 cylinder ver, and 3. 









here's another one:
Automotive supplier KSPG Automotive (formerly Kolbenschmidt Pierburg), a subsidiary of Rheinmetall AG, and FEV have jointly developed a concept for a compact, 30 kW range extender for battery-electric vehicles. KSPG is showcasing the unit, along with other of its engine efficiency technologies such as the UniValve variable valve system, at the Detroit Auto Show.
The new power unit consists of a two-cylinder, 800 cc V-type gasoline engine with a vertically positioned crankshaft and two generators with gear wheel drive. The use of two generators (2 x 15 kW) serves to provide balance for the two-cylinder V-configuration to help to reduce NVH (noise, vibration and harshness) from the engine—especially important in a range-extending application for a battery-electric vehicle, which normally is quiet. 
The system includeshttp://www.fev.com/content/public/?id=1993 FEV’s Full Engine Vibration Compensator (FEVcom), which has been designed into the range extender to reduce NVH. With FEVcom, a reduction in the engine vibration of more than 95% at the engine mount could be measured in various engine applications, according to FEV. 
KSPG sized the output to 30 kW, said Dr. Hans-Joachim Esch, Chief Technical Officer, based on the need for the target A-segment vehicle “_to be faster than a truck_”. KSPG analysis found that 26 kW was sufficient to move the car up a grade of 3% at 100 km/h; they chose 30 kW. 
The engine, with a 90° V, is port fuel injected, with two valves per cylinder, and meets Euro 6 emission requirements. A combined cooling circuit serves the inverter, generator and combustion engine. 
Except for the fuel tank and the radiator, all components, including the power electronics, are mounted on a support frame. The vertical crank shaft requires only a short construction height, such that the module can be integrated beneath the floor of a small passenger vehicle and, for example, be placed comfortably within a spare tire well in the trunk. This installation option offers the easiest and least expensive modification procedure relative to conventional vehicle construction and leaves room for interesting compact vehicle packaging and styling options. 
The range extender weighs a little more than 60 kg, together with the generators and all related parts.


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## PStechPaul (May 1, 2012)

If the car's weight is 1500 kg (3300 lb), then my EV calculator comes up with 25 kW. So that's a really good correlation to their analysis of 26 kW. I don't know their other parameters such as frontal area and rolling resistance, but my default values seem pretty reasonable.

If this genset could be obtained for $3000 or so it would be a game-changer. Even $5000 would be quite attractive compared to a 35 kWh lithium pack.


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## SYNc (Aug 29, 2013)

PStechPaul said:


> If the car's weight is 1500 kg (3300 lb), then my EV calculator comes up with 25 kW. So that's a really good correlation to their analysis of 26 kW. I don't know their other parameters such as frontal area and rolling resistance, but my default values seem pretty reasonable.
> 
> If this genset could be obtained for $3000 or so it would be a game-changer. Even $5000 would be quite attractive compared to a 35 kWh lithium pack.


that's what i'm talking about. can you tell me how much 35kWh worth of lithium would cost, weigh, etc? i'm not well versed in battery tech.

on a side note, i would like to develop a few variants of gen-sets such as this to power larger vehicles as well (work trucks, Mitsubishi fuso type trucks, etc), same principal, a little larger displacement and higher kw output to move a 6000 lbs chevy van, or 12000 lbs fuso.


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## Duncan (Dec 8, 2008)

SYNc said:


> considering its nearly 4000 lbs, I'd say yes, that's pretty impressive mpg, considering its only generating electricity. again with that setup they got a 600 mile range after batteries are depleted.
> 
> and on a typical ICE, when I'm doing 70-85mph my engine revs are around 2k-3k . looking at my power band, i'm generating 100-150 hp at that rev range, overkill imo.


45 mpg on a modern car designed for economy - that is terrible!
-Would have been a good figure back in the 70s
4000 lbs is also bad - tends to be what you get when you increase the complexity too much

_i'm generating 100-150 hp at that rev range,_

No - you have the capability to generate 100-150hp - your throttle pedal controls how much you are actually generating


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## dougingraham (Jul 26, 2011)

SYNc said:


> that's what i'm talking about. can you tell me how much 35kWh worth of lithium would cost, weigh, etc? i'm not well versed in battery tech.
> 
> on a side note, i would like to develop a few variants of gen-sets such as this to power larger vehicles as well (work trucks, Mitsubishi fuso type trucks, etc), same principal, a little larger displacement and higher kw output to move a 6000 lbs chevy van, or 12000 lbs fuso.


35kw of lithium would cost around $15k.

I would buy one of these gensets if they were actually for sale. I can't find a place to buy one. In practical terms they appear to be vaporware.

You still need batteries for acceleration. Most LiFePO4 type cells have a short term C limit of 8 to 10C. This means a cell can produce about 3*10*AHrating or for a 100AH cell about 3000 watts. So to get 150kw (~200hp) you would need at least 50 cells. A 16kw pack would cost about $7000. The 30kw genset would keep everything charged on the highway most of the time. You would never use it in town because you have your batteries and around a 60-80 mile range. You can charge from the grid at a fraction of the cost of the gasoline to power the genset. The grid is as clean as we want it to be.

Everyone assumes the batteries are expensive. If you dont oversize your pack for some mythical trip you almost never make, the batteries pay for themselves in about 3 years in gas savings. This is assuming you only oversize the pack by 20 percent so you dont go below 80%DOD and then oversize by another 20 percent so at the end of the pack life you can still keep it under 80% DOD. Also assuming your current car gets 30mpg, gasoline costs $4 per gallon and electricity costs $0.12 per kwh. Oh, and 5 days a week and 50 weeks a year. All those are reasonable assumptions. If the pack lasts only 9 years you have paid for the batteries, the drive components and for the price of a decent roller.


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## SYNc (Aug 29, 2013)

Duncan said:


> 45 mpg on a modern car designed for economy - that is terrible!
> -Would have been a good figure back in the 70s
> 4000 lbs is also bad - tends to be what you get when you increase the complexity too much
> 
> ...


i dont know if you're serious or you're just trolling at this point. good figure in the 70s, kidding right?

as far as 4000 lbs, because its a lux vehicle, not an eco-box. that car has a 145Kw motor (what is that like 200 hp??) and over 300lbs of torque...

and you're wrong, obviously to maintain the speed, i'll need throttle pedal input (or Cruise control), my engine revving at 3k generates 150hp, obviously without pedal input the revs would drop....


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## SYNc (Aug 29, 2013)

dougingraham said:


> 35kw of lithium would cost around $15k.
> 
> I would buy one of these gensets if they were actually for sale. I can't find a place to buy one. In practical terms they appear to be vaporware.
> 
> ...


i get your points, but i'm also looking to power a fleet of vans, thus batteries would eat away at cargo space, plus it would be too costly to move so much cargo with batteries+ the battery weight. 

and besides recharging at home is practical, but how about away from home? I take regular trips that are over 300 miles in range, I would have gotten a model S, except its all BS and that thing hardly does 200 miles on a full charge. so lets say i was somehow able to make it to Vegas from L.A. what would i do then? "hey Bellagio valet guys, can you guys charge up my tesla while i go work/play" ...


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## SYNc (Aug 29, 2013)

dougingraham said:


> 35kw of lithium would cost around $15k.
> 
> I would buy one of these gensets if they were actually for sale. I can't find a place to buy one. In practical terms they appear to be vaporware.


 you know bmw, you might know kymco, well they build motors, bmw has contracted them to build the range extender for the new i3 (REAL CAR) ,

The range extender engine will be a 650cc Kymco engine borrowed from the BMW C650 GT scooter. It will be optimized to lower noise & vibration and will only put out 35hp, compared to its 65hp when used for the scooter. it is capable of producing 25kw continuous power output. and the car qualifies for the best tier in california rating after zero emissions.


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## PStechPaul (May 1, 2012)

SYNc said:


> i dont know if you're serious or you're just trolling at this point. good figure in the 70s, kidding right?
> 
> as far as 4000 lbs, because its a lux vehicle, not an eco-box. that car has a 145Kw motor (what is that like 200 hp??) and over 300lbs of torque...
> 
> ...


The power/torque/speed curves are maximum, and the actual power you need at any speed depends on the vehicle characteristics and weight, as well as the wind speed and the acceleration. So you need a certain HP to move at a steady speed uphill and less (perhaps even less than zero) to move at the same speed downhill. It is important to understand fully what these terms mean and how they apply to vehicles and motors. Electric motors have vastly different characteristics, and unlike ICE specs, they are usually rated for continuous duty, and overloads can be obtained easily to 2x and briefly to 10x, with a flat torque curve, so a 50 HP electric vehicle can easily beat a 150 HP gasser.

During the gas price crises of the 1970s many people realized that their 20-25 MPG "economy" cars were not good enough and they bought imported cars such as the VW diesel that got about 40-50 MPG and other small gassers that got 30-35. So, yes, 45 would have been good then. My own vehicle is a 1999 Saturn SL1 which averages 35 MPG and gets 45 MPG highway, but starting around 2001 the same models started boasting more power and the gas prices seemed to become stable and well accepted and it became harder to get a non-hybrid with much better than 30 MPG. Even the hybrids got on the zoom-zoom wagon and even now there are car ads that show fast, aggressive, and dangerous driving with statements like "Aggression, in its most elegant form". And once again, usually you must buy imports to get really good fuel economy.


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## Duncan (Dec 8, 2008)

SYNc said:


> and you're wrong, obviously to maintain the speed, i'll need throttle pedal input (or Cruise control), my engine revving at 3k generates 150hp, obviously without pedal input the revs would drop....
> View attachment 17000


_my engine revving at 3k generates 150hp,_

At 3K + full throttle it may develop 150hp,
It can also run at 3k developing zero power or even engine braking or anything in between

Try (carefully) applying gentle throttle in neutral - see how much pedal you need to get up to 3k
Be careful you can blow a petrol engine up doing this

If you have a diesel you can apply full throttle in neutral and it will just increase revs to "High Idle" or "flight speed" 

And yes 45 mpg was a good but attainable fuel consumption in the late 70's 

A more modern target would be what they call a 3 liter car - 72 mpg
A car being developed for mileage should be at least as good as this

Using a gen-set and motor is like "taking a knife to a gun fight"


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## kennybobby (Aug 10, 2012)

*That dyno plot is only for Wide Open Throttle*



SYNc said:


> my engine revving at 3k generates 150hp


Only at WOT-- when you are cruising at 65 the throttle is barely open, check it with your foot sometime...


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## dougingraham (Jul 26, 2011)

SYNc said:


> and besides recharging at home is practical, but how about away from home? I take regular trips that are over 300 miles in range, I would have gotten a model S, except its all BS and that thing hardly does 200 miles on a full charge. so lets say i was somehow able to make it to Vegas from L.A. what would i do then? "hey Bellagio valet guys, can you guys charge up my tesla while i go work/play" ...


You drive it to the Las Vegas supercharge station and plug it in. Fully charged in less than an hour and free. Go gamble or catch a show while charging. Top it off before you drive home.

I know you are joking about asking the Valet guys to go charge your car but I could see that as an honest request and service the hotels will provide at some point.

There will be a supercharge station near where I live sometime next year. I could easily see having a Tesla where I would go charge it once every 2 weeks at the supercharge station while I caught lunch or dinner or a little shopping.


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## SYNc (Aug 29, 2013)

dougingraham said:


> You drive it to the Las Vegas supercharge station and plug it in. Fully charged in less than an hour and free. Go gamble or catch a show while charging. Top it off before you drive home.
> 
> I know you are joking about asking the Valet guys to go charge your car but I could see that as an honest request and service the hotels will provide at some point.
> 
> There will be a supercharge station near where I live sometime next year. I could easily see having a Tesla where I would go charge it once every 2 weeks at the supercharge station while I caught lunch or dinner or a little shopping.


 ive researched this stuff mate, a few problems with your assumptions. first there isn't a supercharger station in vegas, they're planning to have one there by winter 2013, and even then its not in the city, a way bit outside city limits (no clue why). and I cant see it being practical to stop every 100ish miles to eat and top it off (I wouldn't be driving in the desert, without some reserve). the other obvious bit is loss of time from having to make hour long stops (granted the spots are free).
i've asked some of the hotels I stay at, a few have said they have only 120v charging (some for a fee). 
also I've heard on numerous accounts that with supercharger stations, first car gets 70% of the power, 2nd car gets the remaining 30, because its one feed split into each two charging stations. 

anyway, this thing has drifted...
anyone can and willing to help me out with my initial questions?

ie:....need motors (model, links, specs), for a ~3000lbs sedan, ~6000lbs van, and ~12000lbs delivery van.


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## major (Apr 4, 2008)

SYNc said:


> anyone can and willing to help me out with my initial questions?


Sure, why not 



SYNc said:


> Is it not more efficient to transport high current via cables for 10 feet, vs going ice-trans-driveshaft-diff-axles with mechanical linkage?


Yes. Copper cables can transport high current electrical power that distance with probably 99% efficiency or thereabouts. But it is the electrical machinery (motor and generator) and controllers at each end of that cable which will prove to be less efficient that the mechanical transmission of power.




SYNc said:


> ..how much output would be necessary to skip the batteries and just generate electricity and power the motor on demand ?


About 25% more than the existing engine.



SYNc said:


> ..need motors (model, links, specs), for a ~3000lbs sedan, ~6000lbs van, and ~12000lbs delivery van.


Remy makes a very good line of motors. Look here: http://www.evdrive.com/products/evd-motor-controller/


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## SYNc (Aug 29, 2013)

major said:


> Sure, why not
> 
> 
> 
> ...


thank you major. a few questions . what is 25% more, can you put that in terms of power please.
and regarding the motors, how much would it cost to make an ac motor?


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## major (Apr 4, 2008)

SYNc said:


> thank you major. a few questions . what is 25% more, can you put that in terms of power please.


If your car has a 100 hp engine and you replace the driveshaft with cables and a generator up front and electric motor to propel the wheels, then the engine would need to increase to 125 hp for equal performance.



SYNc said:


> and regarding the motors, how much would it cost to make an ac motor?


Somewhere between $250k and a million  Lot, lot cheaper to buy one.


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## SYNc (Aug 29, 2013)

major said:


> If your car has a 100 hp engine and you replace the driveshaft with cables and a generator up front and electric motor to propel the wheels, then the engine would need to increase to 125 hp for equal performance.
> 
> 
> 
> Somewhere between $250k and a million  Lot, lot cheaper to buy one.


i have 50+ vehicles to convert. might be cheaper to develop, funding isn't a huge issue. plus, i think there's a market for affordable a/c motors for builders that is greatly out of reach at this moment. 

also has anyone made any motors for larger applications? i'd rather develop one tailored to the task if it isn't out there. the trucks and vans will be limited to 60mph and do about 75% city, 25% highway. 

looking over logs, some of the vans that are near the 5 year mark have gone through 6,500 gallons of gasoline, avg about 11.24 MPG. some of them are even worse (due to cargo, and careless heavy footed drivers). That is another thing I think would be awesome to address, with electricity and a controller, you can program a set amount of power etc, and prevent my drivers from driving inefficiently. 

that's another reason batteries aren't going to work, way too costly to get and maintain that much worth of batteries. i'm afraid of all the other complications with batteries, workers not charging, discharging too much, running out of power while on the road with cargo. on board elec generation makes so much more sense, esp for commercial vehicles.


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## Duncan (Dec 8, 2008)

SYNc said:


> on board elec generation makes so much more sense, esp for commercial vehicles.


So it makes sense to have to have;
Greater complexity
Need 25% more powerful engines
Burn 25% more fuel


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## Duncan (Dec 8, 2008)

SYNc said:


> i have 50+ vehicles to convert. might be cheaper to develop, funding isn't a huge issue.


I would suggest that if you have 50 vehicles to convert and adequate funding the first thing you need to do is to employ an engineer

A proper engineer who can handle all of the hard sums and knows about power and torque and efficiencies and all of those boring things


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## SYNc (Aug 29, 2013)

Duncan said:


> I would suggest that if you have 50 vehicles to convert and adequate funding the first thing you need to do is to employ an engineer
> 
> A proper engineer who can handle all of the hard sums and knows about power and torque and efficiencies and all of those boring things


yea, its either converting, or replacing them with same old inefficient junk, as these are starting drive train problems and breakdowns. all they need is really new suspension parts and new drive train, frame/bodies are mint. 

IF, it is feasible, I'll employ whatever it takes, but I'm here to first learn, refine my goals, have some knowledge of what I'm getting into (from a tech standpoint). I'd like to learn as much as possible regarding electric propulsion.


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## Duncan (Dec 8, 2008)

SYNc said:


> yea, its either converting, or replacing them with same old inefficient junk, as these are starting drive train problems and breakdowns. all they need is really new suspension parts and new drive train, frame/bodies are mint.
> 
> IF, it is feasible, I'll employ whatever it takes, but I'm here to first learn, refine my goals, have some knowledge of what I'm getting into (from a tech standpoint). I'd like to learn as much as possible regarding electric propulsion.


Ok that makes sense - I was being a bit snarky

You need to do a spreadsheet and input things like fuel costs maintenance costs to compare options

These will depend on things like average and maximum daily usage
Usage patterns - day shift - three shift

Compare re-engine petrol? - re-engine diesel
Battery electric
Hybrid - 
Pure - no battery - hybrid will give the worst possible situation requiring a larger engine than normal IC engined vehicle
Using batteries so that you can size your IC engine to average requirement not maximum power requirement means that you can use a smaller engine
But the extra energy conversion stages - mechanical to electrical and electrical to mechanical will eat more power than you save using a smaller engine 

Set your spreadsheet up 
Depending on the length of the routes and the size of the vehicles you will find either Battery Electric or Diesel as cheapest


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## SYNc (Aug 29, 2013)

Duncan said:


> Ok that makes sense - I was being a bit snarky
> 
> You need to do a spreadsheet and input things like fuel costs maintenance costs to compare options
> 
> ...


well with the calcs ive done far, batteries just wont work, for the safety (its not me using it, its workers who have to mind charge states, etc. 
Diesels pretty much have a 5 yr return on premium paid with current annual usage. 

i dont know how much use one of these packs would be,
http://www.batteryspace.com/lifepo4prismaticbattery128v60ah768wh100aratewithbalancingpcm.aspx
but i'd really rather not mess with batteries, because that introduces chargers, cables, need to upgrade mains, just too cost prohibitive. maybe in my personal car.

regarding the gen-set, has ANYONE attempted it? 
im looking to source something, just need to know kW output i'll be needing to power a motor large enough to get the vehicle moving (which would be how much?). i still think the efficiency factor is flawed the way you explain it, because even though there is conversion, you're building a lightweight engine optimized to turn a 70lb generator, not move a 6000 lb vehicle. As per the links provided, you can see 25kw and 50kw PRODUCTION units have been build from displacements ranging from 650CC to 1200cc. I know i'll need something bigger to hit higher kw range to power the vans, but i also have a personal conversion i'd like to do that I think the smaller units would be adequate for. 
The vans currently have ~5 liter v8s that deliver a poor 280ft/lbs @ 4500 rpm. diesels excel here, but @ 5k premium a piece, that's 250k. plus obviously conversion means little if the driver has a lead foot. electricity is more precise then mech power, meaning power output can be tuned to be just right (no need for gigawatts [BTTF] ref) . you could even tune output to match payload etc. so much stuff once mechanical becomes electrical, its all exciting stuff to me, i personally cant wait to do it.


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## SYNc (Aug 29, 2013)

so what you're saying is i'll need some stored power, for the initial load on the motor (since they take a high amp load to start, then taper off), and then once the draw decreases, the load switches to the genset? did I understand correct?


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## major (Apr 4, 2008)

SYNc said:


> The vans currently have ~5 liter v8s that deliver a poor 280ft/lbs @ 4500 rpm.


So 280 lb.ft. @ 4500 RPM = 240 HP. Multiply times 1.25 for the penalty of going thru the electrical to mechanical conversions, = 300 HP. Convert to kW by multiplier of 0.745 = 223 kW. Actually because the generator is rated for electrical output, and could be overloaded to some degree, you should maybe only need 150 to 200 kW generator rating.

An energy buffer can reduce the size of the generator and engine in some cases. It depends on the duty cycle and system design. And charge sustaining hybrids avoid the necessity of charging from the grid. Here is a system on which I worked years ago. It was a parallel hybrid, which makes more sense in most cases. http://www.researchgate.net/publication/4208093_Hybrid_shuttle_bus_using_ultracapacitors 

However, if your real motive is to control your hired help's driving habits, there are 'control boxes' which can be added to the existing systems to accomplish this for a lot less investment on your part


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## SYNc (Aug 29, 2013)

major said:


> So 280 lb.ft. @ 4500 RPM = 240 HP. Multiply times 1.25 for the penalty of going thru the electrical to mechanical conversions, = 300 HP. Convert to kW by multiplier of 0.745 = 223 kW. Actually because the generator is rated for electrical output, and could be overloaded to some degree, you should maybe only need 150 to 200 kW generator rating.
> 
> An energy buffer can reduce the size of the generator and engine in some cases. It depends on the duty cycle and system design. And charge sustaining hybrids avoid the necessity of charging from the grid. Here is a system on which I worked years ago. It was a parallel hybrid, which makes more sense in most cases. http://www.researchgate.net/publication/4208093_Hybrid_shuttle_bus_using_ultracapacitors
> 
> However, if your real motive is to control your hired help's driving habits, there are 'control boxes' which can be added to the existing systems to accomplish this for a lot less investment on your part


its a combo thing, every bit helps.

but regarding supercaps, ya i found out about them a few months back, and good stuff in the link, but now they are rated at 1 million cycles not 500k.
I found some ev caps, but i dont know if it would work for the amount of power i need. care to help me with that part?

i was looking at via motors setup, and they take the 4.6l v6 and hook it up to a 150kw gen. vans drive 40 miles, batteries are depleted, genset kicks in powering the truck and recharging. so your calc was around there. and they power the trucks/vans with 300kw 11" motors. 

and the regen can be used to charge caps correct? 

ev cap specs:


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## SYNc (Aug 29, 2013)

can you also look at this one? 
Rated Capacitance1 63 F
Minimum Capacitance, initial1 63 F
Maximum ESR DC, initial1 18 mΩ
Rated Voltage 125 V
Absolute Maximum Voltage 136 V
Maximum Continuous Current (ΔT = 15oC)2 140 A RMS
Maximum Continuous Current (ΔT = 40oC)2 240 A RMS
Maximum Peak Current, 1 second (non repetitive) 1,800 A
Leakage Current, maximum (VMS 2.0)4 10 mA
Maximum Series Voltage 1,500 V
Usable Specific Power, Pd 1,700 W/kg
Impedance Match Specific Power, Pmax 3,600 W/kg
Specific Energy, Emax 2.3 Wh/kg
Stored Energy 136.7 Wh
weighs 63 kg


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## dougingraham (Jul 26, 2011)

SYNc said:


> so what you're saying is i'll need some stored power, for the initial load on the motor (since they take a high amp load to start, then taper off), and then once the draw decreases, the load switches to the genset? did I understand correct?


Yes, It doesn't have to be batteries, it could be supercaps, or some mechanical storage system like a flywheel, or even compressed air. But when you do the comparison you quickly find that batteries without the onboard genset are the lowest cost option for ranges of up to around 100 miles. A city delivery van is nearly a perfect setup for an EV. They make lots of stops where they use almost no power and sit still at the loading dock for the 20 minutes it takes to fully recharge the batteries (20 minutes is worst case, if the batteries were only half used it would take 10.) Both UPS and Fedex are looking at EV delivery vehicles. The wild variations in the cost of fuel make profit predictions difficult. The price of electricity is stable.

The LiFePO4 batteries can be charged in 20 minutes if you have a big enough power drop. Tesla's cant because they are not LiFePO4 and the pack is so large it takes an enormous power drop to get to 120kw. Basically the same power as feeds five residences.

Back of napkin calculation. 4000lb delivery van. 100 mile range. You need minimum of 40kwh pack. This will cost about $17500 in batteries (that is a high estimate based on EVTV store cell prices.) From your earlier post (5 year mark have gone through 6,500 gallons of gasoline, avg about 11.24 MPG) we know that a van does 14612 miles in a year. The 6500 gallons of gasoline would be 1300 gallons per year at a cost of $5200 ($4 per gallon). The cost of the electricity to go that same distance at commercial electricity rates ($0.068/kwh where I live) would be $397, a savings of $4803 per year. So if you focus only on fuel cost savings it takes 3.6 years to break even on the batteries. We are expecting the batteries to last around 250000 miles or somewhere between 10 and 15 calendar years which ever comes first. So even if your money costs 10% for the loan to buy the batteries the payback is around 4 years and it is money in the bank after that until the batteries need to be retired. At around the 5 year mark you have paid for the rest of the conversion components. If gas prices go up the payback is faster.

The 40kw pack size I mentioned above will weigh about 835 lbs. About half that weight will be absorbed by the stuff you take out of the vehicle (engine, cooling system, exhaust system. Probably it can go under the bed of the van and take no space. But even if it cant, a pack could be constructed that was about 3 inches thick covering the floor of the van.

To make this work your drivers have to learn to plug it in when they park at the loading dock and unplug it before they drive off. If they can't do that you could always put in inductive charge stations at the loading docks such that they just have to park reasonably.


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## major (Apr 4, 2008)

SYNc said:


> i was looking at via motors setup,


I wouldn't bank on anything Via says  

Got to go........... later.


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## SYNc (Aug 29, 2013)

dougingraham said:


> Yes, It doesn't have to be batteries, it could be supercaps, or some mechanical storage system like a flywheel, or even compressed air. But when you do the comparison you quickly find that batteries without the onboard genset are the lowest cost option for ranges of up to around 100 miles. A city delivery van is nearly a perfect setup for an EV. They make lots of stops where they use almost no power and sit still at the loading dock for the 20 minutes it takes to fully recharge the batteries (20 minutes is worst case, if the batteries were only half used it would take 10.) Both UPS and Fedex are looking at EV delivery vehicles. The wild variations in the cost of fuel make profit predictions difficult. The price of electricity is stable.
> 
> The LiFePO4 batteries can be charged in 20 minutes if you have a big enough power drop. Tesla's cant because they are not LiFePO4 and the pack is so large it takes an enormous power drop to get to 120kw. Basically the same power as feeds five residences.
> 
> ...


thank you for the breakdown doug,. how complex and viable is the super-cap route over batteries? 
the vans weigh in around 4000-4400lbs, with the added battery weight it will cut down on usable weight limits, and probably require a larger pack to move the loaded van 100 miles. and i know i'm being overly paranoid, but i really do not think batteries in comm use will last anywhere near their rated life. i think its diff with a personal car that you take care of at home, at least i know that i'm like that, as are most others. 

and plus in the next few years if battery tech gets safer, cheaper, and denser, i'll have the platform to take advantage of it.


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## SYNc (Aug 29, 2013)

major said:


> I wouldn't bank on anything Via says
> 
> Got to go........... later.


apparently their gear is going to start shipping fall of '13. trucks, with the new gm based truck platforms and new 4.3 liter (replacing the 4.6l) arriving in beginning '14....or so they state. they better have a hell of a lease program considering they want 80k a piece. nut.. 

also...when you have time...or anyone else can look over the cap specs and provide feedback.


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## major (Apr 4, 2008)

SYNc said:


> also...when you have time...or anyone else can look over the cap specs and provide feedback.


My suggestion would be not to start selecting components from a google search. If you're serious, hire a competent engineer, establish the objective and have him do a feasibility study. Then proceed into design where components and subsystems such as the energy buffer will be defined. From there evaluate the suitability of available products on the market. 

Also, I suggest you take a look at HTUF. It used to be Hybrid Truck Users Forum, now is High-Efficiency Truck Users Forum. http://www.calstart.org/Homepage.aspx


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## PStechPaul (May 1, 2012)

The capacitor is 136 Wh which is 486000 W-Sec. Thus it would give you 50 kW for a bit less than 10 seconds, which would be enough for initial acceleration to cruising speed. However, a capacitor does not have a level voltage during discharge, so if your controller can work with half the voltage, you can get just 3/4 of the energy, because it is based on E = 0.5*C*V^2. So let's say 6 seconds.

From my EV calculator for a 4000 lb vehicle accelerating at 8 MPH/sec to 62 MPH requires an average of about 95 kW for 8 seconds, or 760,000 W-Sec. So you would need two capacitors of the size you show.


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## dougingraham (Jul 26, 2011)

SYNc said:


> thank you for the breakdown doug,. how complex and viable is the super-cap route over batteries?
> the vans weigh in around 4000-4400lbs, with the added battery weight it will cut down on usable weight limits, and probably require a larger pack to move the loaded van 100 miles. and i know i'm being overly paranoid, but i really do not think batteries in comm use will last anywhere near their rated life. i think its diff with a personal car that you take care of at home, at least i know that i'm like that, as are most others.
> 
> and plus in the next few years if battery tech gets safer, cheaper, and denser, i'll have the platform to take advantage of it.


I dont think the supercaps are practical yet. At the moment they make batteries seem like a bargain. Too bulky and too expensive. You also need expensive electronics to take advantage of what they can do.

The 4000-4400 lb weight was exactly what I was expecting to see for my back of the napkin estimate. What surprises people is just how much all the ICE stuff weighs. In my tiny RX-7, just the exhaust stuff weighed 90 lbs. The fuel tank plus 16 gallons of gasoline was 124 lbs. I removed the spare tire since it had never been used in the 140k miles the car had been driven as an ICE. That saved 26 lbs. That is 240 lbs and that isnt even the stuff under the hood. Once I removed the motor, cooling system, lead acid battery I ended up taking off well over 400 lbs which all went back on as batteries, motor controller and motor. My vehicle is very little heavier than it was as an ICE. I am guessing that you would end up with a van that weighed only a couple of hundred lbs over ICE.

If you are serious about this you might be well served to find one of the Azure Dynamics Vans and talk to the owners about it. Find out how it really performs and what it costs to drive. The one I have seen was a really good conversion of the Ford Transit Connect. The downside of these was the price. I've seen a couple on Ebay and I think they sold for about $25k. New they were $60k which was too much.

You could also commission a reputable shop to convert one of your current vehicles as a test. A 40kwh pack, WarP11 motor, Soliton 1 control would motivate a delivery van nicely around town. If it works out you could do more of them.


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## ga2500ev (Apr 20, 2008)

I've been out the loop for a bit. Let me address these:



SYNc said:


> easy ,
> 1. grid power is dirty (power companies around L.A. generally have less than 10% renewable in their portfolio).


Batteries have nothing to do with where their stored energy comes from. Charging from the grid is a convenience. If it bothers you, then simply create your own 100% green infrastructure. Quite a few folks here charge at home with a solar or wind infrastructure. Also while grid power is dirty, even when burning coal, the emissions are cleaner than what comes out of car, generator, and mower tailpipes.


> 2. batteries are heavy, inefficient, costly, and too bulky.


Definitely mixing lead and lithium here. And in either case inefficient simply isn't true. As I stated charge/discharge efficiencies are well above 90%.

heavy only applies to lead, which isn't an option in this application. Bulky is a packaging issue. Take a look at the A123 20 Ahr prismatics as an example. And while I'm always harping about how much the capital costs of LiFePo4 is, the total cost of ownership when amortized over a 10 year lifespan can be quite reasonable.


> 3. lithium mining, processing, and transportation seems illogical to the "go green" vision.
> 
> 4. many companies are now producing lightweight/high-output/ CLEAN gen-sets to be used as Range extenders.


These two go hand in hand. The fact of the matter is that any mecahnism for extracting, storing, and transforming energy is going to have an impact cost. The question is always what type and how deep is the impact. 

For example I just read an article that indicated that the 600+ lbs battery in the Nissan Leaf incorporates only 9 lbs of lithium, which is expected to have a usable lifetime of 8-10 years in the car. So while of course it'll cost to extract lithium for storage, what is that cost in comparison to burning hundreds of gallons of non renewable fuel in a "clean" genset?



> lotus and fagor have designed both a 2 cyl and 3 cyl engine that weights around 100 lbs and puts out 50kw of power. It runs between 1.5k and 3.5k rpm range.
> tested on a prototype hybrid car with the 3-cyl engine they managed 45+ MPG after batteries were depleted. also attaining 120g CO2/KM.
> this part puts to rest the antiquated thinking regarding gen-sets being inefficient, heavy, bulky, and DIRTY.
> 
> another company has built a 900cc 2 cyl that produces 30kw and weighs in at 120lbs complete unit. oh and its emission compliant.


They are inefficient by the nature of the mechanism by which they extract energy. They all burn fuel. Most of the fuel goes up as heat. All fuel burning has an emissions impact. And the less that you leverage economies of scale, the more the collective impact is going to be.




> Ok if batteries are absolutely needed, wouldn't this allow for a minimal battery size?
> 
> VIA motors is even doing similar thing with trucks/vans. they hook up a 150kw gen set, and use it to drive the elec motor once batteries are done.
> 
> doesn't chevy volt do something similar? once your batteries hit a preset discharge, ICE+ genset kick in and start sending power to elec motor and excess to battery pack? and if you need a huge deal of power, then via planetary gear the ice produces physical output to drive train.


[/quote]

That's how hybrids work. If it has a plug in option, then you can gian the efficiency of direct battery charging without having to burn fuel to do it. The bigger the battery, the more of that efficiency you can leverage. The minimum size of the battery would be the size to support the peak power needs of the vehicle. For example with the Toyota Prius, the battery can drive the vechicle in electric only mode a bit more than a mile. With the Volt, it's battery can drive the vehicle up to 40 miles in electric only mode.

But once again, with a hybrid, you incur the cost of carrying both batteries, the engine/genset, and the fuel also.This is both a cost in weight, and a cost in space.

The bottom line, and it's simple physics, is that each and every time you transform energy, you get a loss in efficiency. If you are going to burn fuel, then putting the energy directly to the wheels is almost always the most efficient way to do it. 

Starting with the idea of a genset is the incorrect approach. Start with a completely electric infrastructure, then modify it so satisfy your application. Almost always hybrids come to the table due to range anxiety. We are so used to having vehicles that have the ability to travel unlimited distances 100% of the time, we fail to realize that if 95% of the time we are within range, that the vehicle often can still have utility.

I read your other posts. Fleet of vans I believe. You state that battery weight will cut into the carrying capacity of the vehicle. Have you taken into account that a 100% EV removes all the weight associated with the engine and all the weight of the fuel. Gas weighs 6 lbs per gallon. So a 25 gallon tank weighs 150+ lbs.

I'm not saying that an EV is a perfect solution. However, in terms of simplicity and overall cost, it's a sight better than a hybrid. Trust me, once a sufficient fast charging infrastructure is widespread enough, the concept of the hybrid will disappear, fast.

ga2500ev


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## SYNc (Aug 29, 2013)

ga2500ev said:


> I've been out the loop for a bit. Let me address these:
> 
> Batteries have nothing to do with where their stored energy comes from. Charging from the grid is a convenience. If it bothers you, then simply create your own 100% green infrastructure. Quite a few folks here charge at home with a solar or wind infrastructure. Also while grid power is dirty, even when burning coal, the emissions are cleaner than what comes out of car, generator, and mower tailpipes.
> 
> ...


That's how hybrids work. If it has a plug in option, then you can gian the efficiency of direct battery charging without having to burn fuel to do it. The bigger the battery, the more of that efficiency you can leverage. The minimum size of the battery would be the size to support the peak power needs of the vehicle. For example with the Toyota Prius, the battery can drive the vechicle in electric only mode a bit more than a mile. With the Volt, it's battery can drive the vehicle up to 40 miles in electric only mode.
*fully aware, but again these are not series hybrid. *
But once again, with a hybrid, you incur the cost of carrying both batteries, the engine/genset, and the fuel also.This is both a cost in weight, and a cost in space.
*how can you leave out the benefits of: saving of time, $$ , and the fact that you have unlimited range, and ZERO downtime. *
The bottom line, and it's simple physics, is that each and every time you transform energy, you get a loss in efficiency. If you are going to burn fuel, then putting the energy directly to the wheels is almost always the most efficient way to do it. 
*I agree on the physics part, however regarding transforming energy, you'd have to agree that a constant rev engine is more efficient vs a dynamic rev engine*. *something reflected by the volt's mpg rating *
Starting with the idea of a genset is the incorrect approach. Start with a completely electric infrastructure, then modify it so satisfy your application. Almost always hybrids come to the table due to range anxiety. We are so used to having vehicles that have the ability to travel unlimited distances 100% of the time, we fail to realize that if 95% of the time we are within range, that the vehicle often can still have utility.
*again thanks for the input, but I believe otherwise. besides I have other planned uses for the vans if this goes through, so genset is my only option.*
I read your other posts. Fleet of vans I believe. You state that battery weight will cut into the carrying capacity of the vehicle. Have you taken into account that a 100% EV removes all the weight associated with the engine and all the weight of the fuel. Gas weighs 6 lbs per gallon. So a 25 gallon tank weighs 150+ lbs.
*yes, for the amount of range I would consider practical and safe (I dont want the batteries run down too low, leaving a buffer you know?) I'm going to add more battery weight vs weight dropped. Unless my calcs are wrong, or you know of lighter weight packs.*
I'm not saying that an EV is a perfect solution. However, in terms of simplicity and overall cost, it's a sight better than a hybrid. Trust me, once a sufficient fast charging infrastructure is widespread enough, the concept of the hybrid will disappear, fast.
*And trust me, once that structure appears, or capacity increases, I'll be all over it. I'll be the first to rip the ranged extenders out.....But until then, I'd still like to utilize the practical benefits of electricity, and also minimize my impact on the community/planet*. *And my commercial customers served are demanding green. I just cant drop 1.5 million dollars just on the amount of batteries at this moment to meet my needs. at least car manufacturers warranty the batteries (think tesla 8 years) , who would warranty mine ?? *
ga2500ev[/QUOTE]

sorry I dont know how to do that fancy multi-quote thing, hence the bold replies. 

anyway, I'm moving forward with this, 
got someone already working on the gen part.

I've already got some great pricing on those ultra cap modules, PM me for $.

and I need some good pricing on LiFePO4 packs. Can someone help me with this? I'm not sure if its better to build my own pack or buy the ready made ones, in terms of energy density, newer tech etc. I hear LG is making top tier cells? I might just buy the packs ready made for a trial/demo build.
do I want cells? pouches? I'm not interested in different chemistry at this time, just which type of packaging to get.

need some motor help. earlier someone suggested a dc motor, but i'm looking for ac, with the right output to drive the application. 

I guess that leaves the controller and battery mgmt/charger, Need here here too. 

I'm considering a couple options here, either getting a 2002+ express van (looking for a cheap flood victim type car, then stripping it down), using an older van owned (but its prob 400+ lbs heavier body), Thoughts?


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## PStechPaul (May 1, 2012)

For the AC motor, in the quantities you are considering, it may be a viable option to have your own rewound. It costs about $500-$1000 to get this done, and at the same time you may be able to add high speed premium bearings so you might safely reach about 5000 RPM. You probably need about 60-80 HP continuous rating which will have peak power of 100-200 HP. You can start with a premium efficiency 3 phase 4 pole motor rated at about 25-30 HP at 230 V 60 Hz and 1800 RPM. If you are OK with a high voltage battery pack / capacitors / genset, you can use a 600 VDC bus and possibly rewire the motor for delta which will make it nominal 230/sqrt(3) = 132 VAC and you can safely drive it with 180 Hz at 400 VAC and get 3x rated power at 5400 RPM. 

You (actually, a competent and experienced engineer) should be able to build a prototype using a standard industrial motor controller with some fine tuning and maybe external circuitry and microcontroller PID control which give you a more natural torque control similar to what the drivers are used to with an ICE. But with the typical flat torque response and ability to reach short term overload, the response should be even better. 

So you may be able to get a proof of concept vehicle using a junk van ($2000?), a 30 HP motor ($500 used/surplus, $1300 new), and a 100 HP controller (new $3500?), and you would just have to add the batteries and/or capacitors and the range extender to keep them charged. You can start with a minimal pack of about 15 kWh ($8000?) which can give you 75 kW or 100 HP peak, and the 30 kW range extender should suffice for normal driving.

All of these components should be resalable or reusable elsewhere if something does not pan out as expected, so total risk is rather low. But you will either need to acquire a strong education and some experience in AC motors, drives, batteries, and EVs/hybrids, or hire a good engineer.

New drives: http://www.automationdirect.com/static/specs/gs3drives.pdf
New 30 HP motor: http://www.automationdirect.com/adc...remium_Efficiency_(1_-_100HP)/MTCP-030-3BD18C
Prices: http://www.automationdirect.com/static/full_pl.pdf

Good luck.


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## ga2500ev (Apr 20, 2008)

> SYNc said:
> 
> 
> > That's how hybrids work. If it has a plug in option, then you can gian the efficiency of direct battery charging without having to burn fuel to do it. The bigger the battery, the more of that efficiency you can leverage. The minimum size of the battery would be the size to support the peak power needs of the vehicle. For example with the Toyota Prius, the battery can drive the vechicle in electric only mode a bit more than a mile. With the Volt, it's battery can drive the vehicle up to 40 miles in electric only mode.
> ...


The series/parallel format doesn't matter. In both cases the battery serves as an efficient storage of energy and as a peak power delivery system. The only difference between the two is if the electric motor is the only motive force (series) or not (parallel).



> > But once again, with a hybrid, you incur the cost of carrying both batteries, the engine/genset, and the fuel also.This is both a cost in weight, and a cost in space.
> 
> 
> *how can you leave out the benefits of: saving of time, $$ , and the fact that you have unlimited range, and ZERO downtime. *


Because none of these are true vs. a standard vehicle. That has been my point all along. You can fill up a standard van in the same amount of time, at the less cost (because there's less to carry so the vehicle is lighter). You get unlimited range, and of course ZERO downtime is a fantasy for any system and even less so with a series hybrid because now instead of just an engine and transmission that can break down, you have a system where the electric motor, genset, batteries, engine and transmission all have the ability to fail.

The short summary is that there are advantages to all electric or no electric vehicles vs. any type of hybrid.



> > The bottom line, and it's simple physics, is that each and every time you transform energy, you get a loss in efficiency....
> 
> 
> *I agree on the physics part, however regarding transforming energy, you'd have to agree that a constant rev engine is more efficient vs a dynamic rev engine*. *something reflected by the volt's mpg rating *


But it isn't more efficient than no gas engine at all. Not by a long shot. The Leaf gets a MPG rating equivalent to 100+ MPG. The Prius or Volt could not hope to touch it.



> > .... Start with a completely electric infrastructure, then modify it so satisfy your application. Almost always hybrids come to the table due to range anxiety. ... if 95% of the time we are within range, that the vehicle often can still have utility.
> 
> 
> *again thanks for the input, but I believe otherwise. besides I have other planned uses for the vans if this goes through, so genset is my only option.*


It isn't. I acknowledged the fact that a pure EV cannot meet 100% of the needs 100% of the time. Technically neither can a gas vehicle without some assistance. But the point is that if 95% of the targets are in range of the EV and there is only a small percentage of the time that range is an issue, that instead of designing for the 5% exception, design for the 95% usage and supplement for the 5% exception.

Let me try to motivate with a gas example. Say for the sake of argument you were taking your gas vehicle into the bush where there were no gas stations. So as a necessity you would strap on additional gas containers to carry with you on the trip.

Now when you come back home, would you leave those containers strapped on at all times? Or would you build the vehicle with a 100+ gallon tank just so that on the occasion when you went into the bush, you could carry enough gas to make the trip? I think the answers to these questions are kind of obvious.

EV's are exactly the same. Under normal usage there is reasonable range. In addition we all live in electrified environments where opportunity charging abounds. In the cases where there will be insufficient charging opportunities, there's nothing to prevent the temporary addition of a genset trailer as a range extender.

The questions that needs to be asked are how often will the vehicle be used outside of its EV range? Also are those usages outside of range scheduled or unscheduled? Range is only a problem when you did not plan to be out of range. That's why it's called range anxiety.



> > Fleet of vans I believe. ...battery weight will cut into the carrying capacity of the vehicle. Have you taken into account that a 100% EV removes all the weight associated with the engine and all the weight of the fuel.
> 
> 
> *yes, for the amount of range I would consider practical and safe (I dont want the batteries run down too low, leaving a buffer you know?) I'm going to add more battery weight vs weight dropped. Unless my calcs are wrong, or you know of lighter weight packs.*


What are those calculations? I saw the GVW (4000-5000 lbs). But what range are we talking about? Over what timeframe? What charging opportunities are available? Could a vehicle afford to be out of service for a half-hour to an hour during the day? If so, then how many times could that be done?

A moderate sized battery pack and a fast charging infrastructure can serve the same purpose as larger pack and a slower one.




> > I'm not saying that an EV is a perfect solution.... once a sufficient fast charging infrastructure is widespread enough, the concept of the hybrid will disappear, fast.
> 
> 
> *And trust me, once that structure appears, or capacity increases, I'll be all over it. I'll be the first to rip the ranged extenders out.....But until then, I'd still like to utilize the practical benefits of electricity, and also minimize my impact on the community/planet*. *And my commercial customers served are demanding green. I just cant drop 1.5 million dollars just on the amount of batteries at this moment to meet my needs. at least car manufacturers warranty the batteries (think tesla 8 years) , who would warranty mine ?? *


The problem is that it isn't going to appear until it reaches critical mass. And if everyone waits, that mass will not be developed.

As for the cost and warranties, I too cringe at the cost of capitalization. Many have the naive idea that gas is ditched and so the cost goes down. It's just not the case. With gas you have a $100 tank that you fill with $300 of energy each month for 10 years ($36100). With an EV you have a $10K tank that you fill up $25 of energy each month ($13000). While the long term cost favors the EV, you have to put up the $10K up front, and you have to save for the next $10K during. It's a challenge. I ran the above numbers on 15K miles/year, 15 MPG, $3.50 per gallon, 500 Wh/mile, and 6 cents per kWh.

But if you cost it out, it may be worth financing the $1.5 million if even after paying the interest, and saving for the replacements, and you still come out ahead of the fossil fuel in the long run. Also you go greener, and electricity has a much more stable cost platform because it's a regulated utility. Can you tell me what the gas price will be next month?





> sorry I dont know how to do that fancy multi-quote thing, hence the bold replies.


multi-quote pulls in all the messages selected for multi-quote. I use the quoting tag to break up messages into manageable parts. The quote button is on the second row near the right. Looks like the talking bubble with text in it.



> anyway, I'm moving forward with this,
> got someone already working on the gen part.


I'm not saying that the generator is a bad idea, even though it sounds like I am. I am saying that carrying the generator around all the time even if you don't need it right at that moment is probably a bad idea.

Think about batteries to make range reasonable, then having a genset trailer or top carrier for longer trips. Think about putting in a Quick Charge infrastructure so that you can recharge in a short timeframe.

This is what I mean when I say not to make it a hybrid from the start.



> I've already got some great pricing on those ultra cap modules, PM me for $.


The storage energy capacity of the ultra caps are probably not going to be enough. Caps are great when large quick bursts of energy are needed. For this application, batteries are the better bet. You cannot charge/discharge them as quickly as caps. But you can store more energy that you can use.



> and I need some good pricing on LiFePO4 packs. Can someone help me with this? I'm not sure if its better to build my own pack or buy the ready made ones, in terms of energy density, newer tech etc. I hear LG is making top tier cells? I might just buy the packs ready made for a trial/demo build.
> do I want cells? pouches? I'm not interested in different chemistry at this time, just which type of packaging to get.


I have no answer here. Prices have come down, but there are simply so solutions that make you go WOW!



> need some motor help. earlier someone suggested a dc motor, but i'm looking for ac, with the right output to drive the application.


Yet another challenge. You have to balance the efficiency and regen capability of AC vs. the fact that it's going to cost a ton more per vehicle for the motor and controller. In addition as a high voltage application, you are going to need a lot more cells to drive an AC set than with DC. It's really pick your poison between these two. It's an easy decision for me because I'm cheap.

I wish you luck on your project. As a final suggestion, since you are in the pilot phase, try putting together two vehicles and compare them. One hybrid, and one pure EV. Then you can get empirical evidence on cost, range, usability, carrying capacity, and the like.

ga2500ev


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## Duncan (Dec 8, 2008)

ga2500ev said:


> The series/parallel format doesn't matter. In both cases the battery serves as an efficient storage of energy and as a peak power delivery system. The only difference between the two is if the electric motor is the only motive force (series) or not (parallel).
> ga2500ev


Now here I disagree
In a parallel hybrid the energy path is
chemical - mechanical
Gearbox - wheels

In a series hybrid 
chemical - mechanical
_Mechanical - electrical
Electrical - mechanical_
Gearbox - wheels

Those extra stages kill the efficiency

IC engine efficiency
There seems to be a misapprehension that restricting the speed range of an IC engine can cause some sort of magical increase in efficiency.

In practice the efficiency of an IC engine *does not change a lot across quite a wide speed range.*

The efficiency does change significantly across the load range, the efficiency at low load is a lot worse than the efficiency at maximum load 

This means that you can use an engine coupled to the gearbox with electric motor assist to allow the use of a smaller motor and increase the efficiency
(Parallel Hybrid)

But using a motor at a constant speed to drive a generator to drive electric motors does NOT give an advantage in IC efficiency as you have to modulate the IC engine load to achieve the required electrical power which means you have to run the constant rpm IC engine in a lower efficiency low load condition


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## PStechPaul (May 1, 2012)

Valid points, but for a series hybrid you can turn off the ICE and wait until batteries are sufficiently depleted to run it at full power and optimum efficiency. For a parallel hybrid, it is necessary to have a very efficient multispeed gearbox or a variable ratio mechanical drive to run the ICE efficiently under varying load conditions.

The parallel hybrid has an advantage when the ICE and electric motor are used together to get higher maximum power than either alone. Also it can use the electric motor as a generator, rather than a separate device, but it may not be as efficient. 

I like the idea of the series hybrid because it can operate as a true EV and then optionally connect the ICE/generator set when and if needed with just simple electrical wiring. The parallel concept involves more complex mechanical engineering.


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## Duncan (Dec 8, 2008)

PStechPaul said:


> I like the idea of the series hybrid because it can operate as a true EV and then optionally connect the ICE/generator set when and if needed with just simple electrical wiring. The parallel concept involves more complex mechanical engineering.


Ok that would be valid - 
But only if you only needed the IC occasionally 
and even then you would have losses from the extra weight
The only way that would make sense would be if you only mounted the gen-set as a range extender that was needed occasionally 
Probably the best way would be to have either a trailer or one of those rear towbar mounts

The main difference is going to be where you get your energy from
If you get most of your energy from the grid a BEV with series range extender MAY make sense
If you intend getting most of your energy from petrol then a series hybrid makes NO SENSE AT ALL


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## Tesseract (Sep 27, 2008)

electriccars101 said:


> As a matter of fact, it does not matter what you are going to use for your acceleration. It does not matter as long as you have a balanced ratio between the machine and the weight of the car. There are a lot of specifications needed for this but make sure that you do not compromise.


This is a nonsense answer... are you replying just to advertise your book/website?


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