powered trailer idea (EV pusher trailer to make conventional car a hybrid)

[Tango Charlie]

I just found an old (2005) thread by MetroMPG about a powered trailer. MetroMPG.com: Electric pusher trailer
I was wondering if there was any more thought from the ecomodding community of the merit of such an idea. What situation/application would such an idea be ideal? I'm thinking more along the lines of a trailer assist that would be more universal. i.e.: able to be towed by any standard gas guzzler to help efficiency when being towed. How about a small diesel on the trailer running a generator to power electric drive motors. Like a (scaled down) railroad locomotive.

[MetroMPG]

As a matter of fact... I just sold one of the "surplus" golf cart controllers to a guy in Texas who is building an electric pusher for his PT Cruiser. If he builds it, he'll be the first of many people who've wondered about this idea (that I know of).



More pics of his progress in the builder's Flickr album: http://www.flickr.com/mbarkley



I'd think the best application for something like this would be for low speed "EV mode" and assist.

[ebacherville]

design the trailer properly and you could gain a boat tail out of it.. could serve two functions..

I know I saw a EV Volkswagon with a diesel pusher trailer..running biodiesel.. kind of cool for extended range for EV's

[Tango Charlie]

Originally Posted by MetroMPG

As a matter of fact... I just sold one of the "surplus" golf cart controllers to a guy in Texas who says he's building an electric pusher for his PT Cruiser. If he builds it, he'll be the first of many people who've wondered about this idea (that I know of).

Cool. Is he a member? If so, hopefully he'll post a thread!

Originally Posted by ebacherville

I know I saw a EV Volkswagon with a diesel pusher trailer..running biodiesel.. kind of cool for extended range for EV's

Do you have a link, etc.?

[Shawn D.]

I have to say that this is one of the coolest concepts I've heard about in a while. It's certainly doable!

[mattW]

I think that's texoma EV if i'm not mistaken; he started a thread about it here on our site. Small World hey, lol.

[ttoyoda]

While a neat idea, any such design should reduce or turn off the trailer power when the vehicle and trailer are not in a straight line. Otherwise the trailer could cause uncontrolable oversteer in a turn. And then you will not be happy.

[Andyman]

I think the ideal application for a powered trailer is a sports car with a big engine. The trailer could have some kind of power that is more efficient for low power use such as an electric motor, a small gasoline or diesel engine, a hydraulic accumulator, compressed air engine or a flywheel. I think the hydraulic accumulator might be the best solution. It wouldn't use any power when stopped and it could easily be recharged by turning on the car's engine and driving while setting the trailer to pump oil back into the high pressure tank. It could also recover energy while braking. For even better efficiency, it might be good to use a small engine on the trailer to keep the accumulator charged up. The extra engine could shut off when the accumulator was full. One possible complication is that adding an engine might be considered tampering with the emission control system. It might also be possible to use a collapsible windmill to recharge the accumulator or batteries when the vehicle is parked. The trailer could also have some extra room for luggage to add to the skimpy luggage space in sports cars.

This system would save lots of fuel when driving slowly in heavy traffic if the car's engine could be shut off. It might be necessary to add some way of charging the battery, keeping vacuum in the power brake booster, pumping steering fluid for power steering and pumping transmission fluid in an automatic transmission to protect the bearings.

Here are a couple of articles about using hydraulic accumulators in cars.

http://www.motherearthnews.com/Green...s-Mileage.aspx

http://www.motherearthnews.com/Green...-Gasoline.aspx

I also like the idea of using a solar and battery powered trailer with a bicycle.

[steensn]

AS Andyman has stated a bit, this is a MUCH harder integration in a new car than an older car. In my base model Aspire with no power steering, no ESP, no auto trans, etc. integration is easy because almost nothing it automated. If you want to turn off the engine and use it to power you forward you have to come up with a VERY complicated system integration that my company into the GM Tahoe 2 Mode Hybrid.

In the end, aren't you just adding a ton of more weight and in-stability to try and garner minimal payback. Would the powered wagon be able to push the vehicle? IE, would the friction of the tires (dependant on trailer weight) be enough to push the vehicle forward? Will it "bind up" under a normal trailer ball and hitch interface?

I'm not saying it won't work, but there are some obstacles to overcome depending on the car make and model. Now not shutting of the car would be a different story, much easier that way.

[Tango Charlie]

Originally Posted by ttoyoda

While a neat idea, any such design should reduce or turn off the trailer power when the vehicle and trailer are not in a straight line. Otherwise the trailer could cause uncontrolable oversteer in a turn. And then you will not be happy.

Yeah, jack knifing on snow and ice covered roads would definitely be a concern. But thats what sensors and computers are for.
The guy with the EV porsche pushed by the VW Rabbit trailer claimed no oversteer problems even with (if I remember correctly) full push and the tightest turn radius. No snow in CA, though. *sigh*