eCar - Hybridization

[DrkAngel]

Most people would like a true eCar but, due to range limitations, feel it necessary to settle for a Hybrid.

These calculations are based on the BMW "Mini E", mainly because it is the most efficient, (that doesn't look like a pedal-car).

Unlimited range - bumper mount a 16hp, 10kwh generator. This will provide power, nearly equal to continuous highway travel, (mpg unavailable.)
Total weight - 200 lb, plus gas and bumper mount, (equal to 1 large passenger).

http://cgi.ebay.com/NEW-16HP-10000-...itu=UCC&otn=5&ps=63&clkid=5477529288326174360


200lb+ ... but more efficient than most!
Electric starter & battery might be worth the extra weight!?




Extended range - 12hp, 6kwh generator. This will provide 50%+ of the power required for highway travel, effectively doubling range from 150 miles, to 300+ miles! Total weight - 125lb, (plus gas & bumper mount). Less than a typical male passenger.

Alternative to bumper mount would be a small trailer. An aerodynamic design, no taller than vehicle, should increase power requirements, only slightly. Trailer will also increase luggage capacity, for trips!

I'm not sure, but it is possible that a separate generator, might bypass emission control requirements.

At the very least, I would always carry around the 2.5hp, 1500 watt, 4-cycle generator that I picked up.
Only 52lb & small!
Getting stranded is no fun!

Highly recommended, would be a 4 cycle, compared to 2 cycle (2 stroke). 2 cycle might be lighter, but is less efficient and requires mixing oil w/gas.

If weight is not a primary concern, a Diesel generator will provide the best "mpg", (trailer highly recommended.)

 

[Hillhater]

I like the "Power Pack" trailer idea as most of the time your Ecar could be used for the shorter local commutes on its own battery, then when you want to get away for the weekend or take the occasional longer trip, just hook up the "power pack" trailer (together with your luggage, Ebike etc ) ..and off you go ! 8) :wink: .. neat idea !

PS: just thought... maybe you could also pick up a used Prius battery pack and slip that into the trailer also !
I also wonder if anyone has considered having trailered batteries as a possible alternative way of dealing with the "battery swap" proposals for EV's on longer journeys ? Something like a Rental car deal, except for "power pack" battery trailers that can be swapped at service stations. ! ??

 

[Hillhater]

further thinking ...
This has been done before apparently ...12 years ago !
Moller International (AKA Freedom Motors) , California based makers of the Freedom rotary engine (Wankel) tried to demonstrate the use of a portable power pack (Generator) on an EV honda civic. ( They even used a trailor !)
http://www.freedom-motors.com/index.php?option=com_content&view=article&id=70&Itemid=70
It was not a success due to the 1998 technology lead acid batteries....but their generator seems to be ideal..

This one is a 40lb , 5 kw unit but up to 25 kw in a small lightweight package is possible ( they produce them for the Military)
I suspect it may be a few more dollars than the Ebay unit tho !

 

[spinningmagnets]

I am a fan of the series-hybrid configuration, especially if the range-extender engine is on a trailer or an easily swapped in/out module for a truck. It wouldn't appeal to everyone, but I believe it has merit for some situations...
http://endless-sphere.com/forums/viewtopic.php?f=10&t=13744
http://www.evalbum.com/122.html

 

[neptronix]

Rotaries are great because of their weight and small size.
But don't forget that they eat up to 50% more gas than a piston engine of equivalent horsepower. They also seem to all burn some oil by design. I don't know of any rotaries that don't.

That's why they haven't seen widespread usage anywhere. Maybe they're good as a 'limp home' generator, but for any regular use, geez you might as well just buy a Prius and forget about the whole EV part.

 

[spinningmagnets]

I am a fan of rotaries, but they have characteristics that limit their applications. They are power-dense, so they remain a popular option for small home-built planes. They are 'fairly easy' to rebuild, but they require frequent rebuilds due to rapid rotor seal wear. If the case chamber is scored at all, the case is toast, you can't just give it a light bore and hone, like a cylinder...

The rings of a cylindrical piston are a lot more sophisticated that they may at first appear. It is pretty amazing how they smear just the right amount of oil film to allow their pistons to live for over 100K miles, yet their oil consumption (oil is spread 'up', and scraped 'down') is amazingly low.

Imagine the difficulties of the seal engineer for Wankel rotaries. Add enough oil-spreading to make the seals last longer, and the emissions go up so that it won't pass the California smog regs. Each rotor has three tip seals and six side seals, and each slightly resembles a leaf-spring.

A machinist can make a fairly perfect cylinder with affordable machinery and methods, the odd shape of the Wankel 'cylinder' must be shaped and then chrome-plated to make it last long enough to be worthwhile...

 

[todayican2]

The more I dig into it, the more excited I get.

Even doing the "prius thing"

DIY Evers NEED to build efficient cars, and the prius is, at the end of the day a factory built big car, admittedly with decent aero.

I got off the phone with another forum member last night getting spectacular fuel economy with a diy series hybrid.

Im shooting for 200mpg at 70mph with an air conditioned enclosed trike

 

[neptronix]

oh and by the way, watch out with that gas engine. The electric gods smited Niel Young's LincVolt abomination because he added a gas motor.. just sayin

 

[x88x]

This is my personal favorite series hybrid.
http://www.capstoneturbine.com/news/story.asp?id=536
Factory 5 GTM Supercar with 80 mile LiPo range and a 30kW diesel microturbine.

 

[damcard]

This has been done before apparently ...12 years ago !

I have wanted to do this every since I saw http://www.motherearthnews.com/Green-Transportation/1979-07-01/Electric-Car-Conversion.aspx. I want to do a late 80's BMW 3 series, a small dc diesel genset, WarP HV 11" dc motor, one of NetGain's controllers, and a bunch of Maxwell super caps. I think it would be cool to have a fast 1/4 mile car that can also be a daily driver with decent gas mileage. -Damcard.

 

[Hillhater]

This is my personal favorite series hybrid.
http://www.capstoneturbine.com/news/story.asp?id=536
Factory 5 GTM Supercar with 80 mile LiPo range and a 30kW diesel microturbine.

Hmm ? that 30kw micro turbine genset does seem to be the ticket..
..lightweight , powerful, low maintenance, able to run on most fuel sources, and low emissions too.
I believe these are what Jaguar has used in their C-X75 hybrid.
.. i wonder what it costs ?

 

[x88x]

This is my personal favorite series hybrid.
http://www.capstoneturbine.com/news/story.asp?id=536
Factory 5 GTM Supercar with 80 mile LiPo range and a 30kW diesel microturbine.

Hmm ? that 30kw micro turbine genset does seem to be the ticket..
..lightweight , powerful, low maintenance, able to run on most fuel sources, and low emissions too.
I believe these are what Jaguar has used in their C-X75 hybrid.
.. i wonder what it costs ?

I did actually look into it a while ago..shortly after I first saw an article for that GTM series hybrid, actually. I don't remember what the exact number was, but iirc it was quite expensive (at least the Capstone C30 in that GTM anyway), somewhere around $30k.

 

[todayican2]

Great article Damcard!
http://www.motherearthnews.com/Green-Transportation/1979-07-01/Electric-Car-Conversion.aspx

 

[x88x]

July/August 1979

in fact, all the technology incorporated into his design has been available for about 35 years, just waiting for someone to put two and two together and make the whole thing work

And it only took a large company another 31 years to actually put out a similar product...that's progress for you, blindingly fast.

Seriously though, that's a pretty awesome article. ..he even used regen braking on it! ..that figure for the battery charging though...15 minutes from 25% to 100% on flooded lead acid?

 

[Hillhater]

Sorry , but there is an awful lot of bull sh1te in that article !...

because of the fact that the motor has a low draw at cruising speeds: only .23 amps at 1,800 RPM. Since the Briggs & Stratton engine turns at a fixed rate and can generate 100 amps at about 28-1/2 volts, normal driving presents no problem.

how the heck do they expect us to believe that any car can "cruise" using only 11 watts !! ( 48v x 0.23 A)
..and having stated that the generator produces 2.8 Kw, do you really believe that it can move much above 5 mph at all once it has burned up the 2 or 3 Kwhrs in those 4 batteries !

No wonder we never heard any more of that idea.
Like every EV project, ..it needed more and better batteries to perform reasonably.
dust it off now , throw in 50Kwhr of LiPo and it becomes believable. ( until they run out also !)

 

[damcard]

They did a couple more articles about it. I found one. http://www.motherearthnews.com/Green-Transportation/1993-06-01/Hybrid-Electric-Car.aspx There was another where they reproduced the concept with a Subaru. Ill try to find it. It may have had a limited range back then, but with a good generator I would think it would be viable today. Is it? If I ever got my hands on one of those Wisper generators, I would definitely do one. -Damcard

 

[damcard]

Here they admitted some incorrect data from the first article. http://www.motherearthnews.com/Green-Transportation/1980-09-01/Mothers-Own-Hybrid-Car.aspx -Damcard.

 

[Hillhater]

Unless you have a battery pack to do 80% of the load , there is no point in using a low power IC gen set to provide drive power.
You would not want to be driving any distance using the gen set as primary power... thats just inefficient and also impractical if less than (say) 50Kw.

 

[todayican2]

Huh? For an f250 maybe, a civic for example is closer to 9kw to maintain 70mph

 

[x88x]

You would not want to be driving any distance using the gen set as primary power... thats just inefficient and also impractical if less than (say) 50Kw.

Inefficient compared to what? The main point of a series hybrid, once you run out of batteries, is that the engine can run at peak efficiency 100% of the time instead of ranging all over the place like it would if it were connected directly to the drivetrain. Check out trains and heavy earthmoving equipment. They've been using systems like that (minus the batteries) for years.

 

[Hillhater]

Inefficient compared to what? The main point of a series hybrid, once you run out of batteries, is that the engine can run at peak efficiency 100% of the time instead of ranging all over the place like it would if it were connected directly to the drivetrain. Check out trains and heavy earthmoving equipment. They've been using systems like that (minus the batteries) for years.

Inefficient compared to a direct IC mechanical drive..without the electrical losses in the generator , drive controls and motor.
You could use a CV trans,or multispeed gbox (8 speed gbox's are in use now) to keep the motor in the max eff range.
Trains and Heavy earth movers use "Electrical transmission" to avoid complex , heavy, high mainteance,..mechanical transmissions and impractical braking systems ...nothing to do with drive efficiency.

...a civic for example is closer to 9kw to maintain 70mph

...if you say so maybe.....until you get to a hill ..
and just how long would 9kw take to get you up to 70mph ?? ( remember , you have used all your batteries in the previous 50 mile run)

 

[todayican2]

Unless I am missing something were talking about a range extending gen, where the batteries are still in play. so no waiting (admittedly) forever and a day for 9kw to accellerate the theoretical civic to speed, nor having poor hill performance., thats what the battery pack is for.

In my opinion, barring 100% EVs which people are going to demand, and others will be unable to accept due to travel needs that dont match the drive profile. Hybrids are going to need to fill that gap.

Im building one, and think that specking the ICE to be about 125% the need of highway driving at 70mph will be just the ticket. It can via the regen, feed power back to the batteries at cruise speed. efficient use of fuel, maintaining the Battery pack so it can do what it does best (drive at speeds under 50, help go up hills, and accellerate) and let the diesel do what it does best, drone on at a set output.

 

[Hillhater]

Agreed, but you must be realistic about how much power you need for that 70mph cruise, what peak demand, and what the overall average power draw ( demand profile) is that you need. (IE:- acceleration, hill climbing ability, range etc).
Then you can figure out what size battery, generator , etc you need.

The main point of the previous posts were related to that old EV with a 3kw gen and 4 lead acid car batteries, and how impractical it was.

 

[DrkAngel]

Previously mentioned, 16hp - 10kwh, seems to be about the proper power range.

Although, ... a DC generator might be much simpler to set up and configure.

Diesel engine would be most effecient, followed by a gas 4-cycle engine.

Also important is a permanent magnet generator. Certain, lighter weight generators use power robbing electromagnets.

 

[Hillhater]

16hp - 10kwh, seems to be about the proper power range.

possibly , but you notice that the 16hp gen set you originally pointed to was actually rated as 10kw "peak" and 8kw continuous.

Also it quoted "10hrs run time at 50% capacity" with a 8.3 gal fuel tank. Presumably representing its max efficiency ?
So, if you believe that that 50% represents 4kw continuous running, and maybe that 4kw could maintain a road speed of 40mph (??)... then that would represent range of 400+ miles....but at a fuel consumption of about 50mpg
( remembering that at 4kw you are not going to be able to recharge your battery's whilst maintaining 40mph)

I guess i fail to see the point, since there are many ICE cars that can better that 50 mpg whilst giving a much higher performance than a steady 40mph !