VIDEO: Fifth Gear reviews electric Smart car, turns it into series hybrid with off-the-shelf generator
This week, Fifth Gear did a side-by-side review of the Mercedes Smart electric drive and regular Smart car that runs on petrol (watch it below the fold). Fifth Gear found out that zero-to-thirty is a lot faster in the petrol but the handling, thanks the heavy batteries lowering the center of gravity, is tops in the electric. Just 100 Smart EDs (electric drive) are coming to the UK as a trial, and the launch will be based on demand, according to Fifth Gear. I think Fifth Gear's distance/cost comparison is kinda biased to the electric but the show does something very interesting at the end of the review. They put a portable gas generator in the back of the EV, charging the car and instantly turning it into a series hybrid. Why don't we see that more often?
[Source: YouTube]
Reader Comments (Page 1 of 1)
Seth 6:00PM (3/04/2008)
Actually, that's an idea I've been mulling over for a while. I'd like to try making an electric motorcycle that has a generator strapped to the back. I imagine it would be a much more efficient powertrain than the standard gas motorcycle.
Anyone else out there (in the NW) willing to go in on something like that with me? :)
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Chris 6:14PM (3/04/2008)
Aren't these smaller gas engines horrible with respect to emissions?
I'm no engineer but I'm guessing the gas to electric to propulsion conversion in this particular scenario isn't very efficient.
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Michael Wendell 7:39PM (3/04/2008)
this really doesn't work. visit any hardcore EV mailing list and ask the question, it's been discussed ad infinitum.
not only is the generator extremely dirty in regard to emmissions, but the energy losses from converting gasoline to kinetic energy and back to electrical energy and back to finetic again make the setup far less efficient than simply building an internal combustion powered vehicle.
while i think there is a future for this type of drivetrain (chevy volt anyone?), it's not going to come from carrying a cheap genset in your trunk.
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iDevin 7:25PM (3/04/2008)
@Chris
You have a good point there, but going gas to electric via a small generator may be more efficient due to the fact that the generator is likely to be operating at a more efficient RPM than the gas motor driving a regular car. That's one of the ideas behind the Chevy Volt is that you have a very specifically designed engine that only runs at it's most efficient speed when charging the batteries.
That said the key words there are "specifically designed" and an off the shelf generator plus off the shelf EV parts are likely to be less efficient than the original gasoline power train.
There was someone who rigged up a RAV4-EV with a generator on a platform on the back and they had a lot of info on it, including if memory serves some info on efficieny, but I can't find the website right now. If I find it I'll post it here.
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rgseidl 7:48PM (3/04/2008)
@ Seth -
you might want to use a bike with a sidecar as a development platform. Remove the chain, replace the front and rear sprockets with suitable electric generator and motor, resp. You have the option of adding motors to the other wheels as well. The power electronics and batteries go in the sidecar.
Depending on the type of battery you choose, you may need a cooling system to ensure long life. Also, avoid deep discharges of the type perpetrated by VBH in the above film, for the same reason.
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Joe 9:02PM (3/04/2008)
My old tech-ed teacher had a plan to convert his Jeep Wrangler to electric and then build a trailer with a generator on it for extended range when needed.
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Chris M 11:57PM (3/04/2008)
The video graphically showed what has been known for a long time - driving on "electric fuel" costs a lot less than fossil fuels.
While the idea of adding a generator is a good one, putting the generator inside the car and breathing the exhaust fumes isn't such a good idea.
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Eric Boyd 3:14AM (3/05/2008)
iDevin - I did a search after seeing your hint and I think I found the car you are talking about:
http://evnut.com/docs/rav4evpfc50.pdf
If you go to the bottom of the document, they talk about hooking up a Coleman Professional 11000 generator (~11kW) to their (retrofitted) onboard charger, and getting ~27 MPG in charge-neutral mode. Unfortunatly the generator is not quite large enough to travel at highway speeds (they claim about 60 MPH top speed without depleting the battery), but it's still pretty cool!
They also link to a more official version, actually commissioned by Toyota!
http://evnut.com/rav_longranger.htm
It gets an astonishing 38 MPG and is strong enough for sustained operation at any speed. It really makes you angry that Toyota doesn't make RAV4-EVs anymore. I mean, have a few of these trailers around for lease for long trips and it's an awesome vehicle!
Eric
http://xprizecars.com/
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a 5:08AM (3/05/2008)
Hi Linton, you made a mistake in your article. You claim that that the electric Smart was better in the handling. Watch the video again. The petrol car beat the electric car in the slalom by nearly 2.5 seconds.
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Tim 9:35AM (3/05/2008)
The important bit that was NOT mentioned here was displacing imported oil with renewable electricity produced on the roof of your own home.
Electric cars are for the daily commute. You can rent an ICE "Hybrid" for those occasional long trips or better yet, take the train and rent an electric car once you reach your destination.
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dwf 11:36AM (3/05/2008)
A generator to charge the batteries is call a Series Hybrid, and it IS being done. Just go to the center column to the right and under the "Manufacturers" heading click on Aptera and Venture Vehicles to see examples of Series Hybrid vehicles.
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brn 11:58AM (3/05/2008)
"electricity produced on the roof of your own home"
The roof of my own home is currently covered with snow. The current outside temperature is well below what most EV batteries are willing to charge at. I'm also curious as to how well these batteries hold a charge while the vehicle sits, in the cold, at work for 10 hours. You can bet my employer isn't going to let me plug it in.
I love the idea of EV, but it doesn't make sense to me. I'd need something that can truly replace my gas vehicle. Even putting range and cargo capacity aside, it doesn't seem feasible with current technology. Add the issues of range and cargo capacity, and we're looking at a long way down the road.
If ya 'all think I'm in left field, let me know.
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Lascelles Linton 12:32PM (3/05/2008)
Hi a, You are correct but I meant she said it was "easier to drive." Also, she mentioned the heavy batteries which I wrote about before and wanted to link :D
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thesawzall 3:13PM (3/05/2008)
With the Smart car's size, you could actually fit two into your garage. One could be charging from the house's rooftop solar panels, while you're using the other. The next day simply swap cars. Of course the other spot in the 2-car garage goes to a gas car for highway drives.
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virgil 6:30PM (3/05/2008)
Not wishing to pee on anyone's fireworks here, but won't charging and depleting at the same time really screw up the battery? Surely these things are designed with software that specifically never expects to be charging and running at the same time. I'm surprised there isn't some sort of disable to prevent people doing this.
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mike 6:40PM (3/05/2008)
I think this is an interesting idea for emergency's. 99.9999% of the time you should drive an electric within it's range.
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mike 6:41PM (3/05/2008)
When can I buy one in the USA.
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Luke 7:22PM (5/11/2008)
"With the Smart car's size, you could actually fit two into your garage. One could be charging from the house's rooftop solar panels, while you're using the other. The next day simply swap cars. Of course the other spot in the 2-car garage goes to a gas car for highway drives.
"
Or, you could buy two homes, each with it's own Smart car. LOL!
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