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

[bschloop]

a four wheeled trailer with the front wheels on a single axle that pivots at he center would be extremely difficult to back up, as you are in essence pulling two trailers attached to each other. castor wheels at the front of a trailer on the other hand may work, but you would need to make sure they were well maintained, a bound up castor would act like a beat up shopping cart that always pulls to one side or shakes violently. personally I would probably try a single castor wheel under the tongue that is adjustable to change the load on the to vehicle. just make sure it's a tall enough wheel to handle potholes, and maybe consider a suspension of some sort so it doesn't rip your hitch off your car. also, trailer brakes would be an absolute must have.

[EZP 545]

Unloading the hitch is very desirable. My present rig is a small standard 2 wheel trailer, but thoughts are;-
2 wheels not to far bebind the rear vehicle ones, and something like a 3 point tractor location, which could move up and down, but not sideways. trailing wheels (to go up and down verticlally) pivoted from the center, so no rear vehicle wheel unloading can occur for the range of the trailing units suspension. This effectivly becomes part of the vehicle, and appart from the tire drag as a tandem trailer has, could be backed as just a longer vehicle.
This is an approach I am considering for when the power / pusher development progresses. Removable for EV only use.

[MetroMPG]

George sent me a bunch of photos of his projects - I'll post them this evening or first thing in the AM.

[MetroMPG]

I've posted them as two separate threads based on the photos & descriptions George sent. (But I think they're all genetically intertwined, so the separation is arbitrary on my part!)

Some really fun, ambitious & interesting projects going on here:

• http://ecomodder.com/forum/showthrea...ius-22189.html

• http://ecomodder.com/forum/showthrea...ius-22193.html

[oldtamiyaphile]

So I need to build a new trailer for work and I'm thinking of finally trying my hand at EV propulsion.

The tow vehicle in question weighs 1400kg (~3000lbs) and the trailer should come in at under 300kg (~660lbs - minus the electric drive system). It's used 99% of the time in city traffic, I don't need the trailer to be capable of any more than 70km/h (~45mph)

I don't expect the trailer to drive the car as such, I'd like it be able to move the car with the engine off in traffic and assist in EOC distances. Ideally, I really want regen braking, as in city traffic (some days less than 15mph avg speeds) that would help a lot.

So I'm thinking of using a big R/C aircraft motor, something like this:

Turnigy RotoMax 150cc Size Brushless Outrunner Motor

It puts out 13hp and can be had for around $400. I could use an R/C controller too (around $300) if the currents can be contained, maybe not likely. The way I see it is even if I needed to use two of those motors, $1400 for 26hp with controllers would still be economical).

Does this seem like a possible way to power my trailer, or would I be better off sticking to something more like a golf cart/ forklift motor etc.

I don't think any of these options allow regen, what's the cheapest way to do that?

Just thinking out loud, any input appreciated

[Xist]

The United States Army has a truck called the Load Handling System. How is a truck a "system?" We called the truck and trailer an "LHS System," apparently for the sake of redundant repetitiveness. I think that it is a clever system. The front axle of the trailer pivots and whenever you back up, the trailer buckles, because it is easier for the front axle to move (sideways) than for the rear axle to roll backwards.



However, when you have the front wheels straight, you can lock the pivot point, but it always takes a while to get those wheels straight.

[freebeard]

I don't think any of these options allow regen, what's the cheapest way to do that?

I understand that regen requires AC which requires FOC which gets complicated. Maybe a 2nd DC motor mounted in reverse and an A-B switch?

[synergy]

Elon Musk says Tesla will unveil a new kind of battery to power your home | The Verge

I can't seem to find a reason why tesla DOESNT do this.

Why take a tesla battery and put it on your wall at home when you could add it to a trailer. Offering a non powered version for electric cars and a powered version for non electrics.

You could rent them from rental places or they could make a Application similar to uber where one could be dropped off to you fully charged. No more range anxiety you just swap a trailer in 5 minutes or less.

I think Tesla would be one of the only companies who could pull it off.

And would a powered trailer possibly qualify for the 7,500 tax rebate?

[oldtamiyaphile]

Originally Posted by freebeard

I understand that regen requires AC which requires FOC which gets complicated. Maybe a 2nd DC motor mounted in reverse and an A-B switch?

Can I do regen on a DC drive motor, say a forklift one?

R/C DC motors do regen, my understanding is that the problem with larger motors is it's difficult to deal with back EMF, not really sure. I have plenty of electric motor experience, but only at smaller scales.

I don't think R/C brushless motors do regen, at least not the big ones. It's not really an issue for their intended use as aircraft wouldn't gain much from regen.

I'm going to start with a basic trailer, get it registered, then add a diff and experiment from there. I'll need something like a Toyota Hilux diff with the lowest ratio I can find.

Integrating a DIY hybrid into a manual trans car is difficult from a driving point of view, but I've got a basic method worked out. Two modes, low speed and high speed. Low speed is for creeping in traffic etc. Works engine on or off, gear in neutral. Motor controller is connected to the DBW throttle and you simply accelerate and the motor accelerates. Cuts off at say 8km/h where you're likely to be going for second gear. I would also like to use this for bump starting to spare my starter motor.

High speed mode, intended for increasing glide distances, waits for car to be in neutral and engine off, then the accelerator controls the electric motor rather than the ICE.

It's a pretty narrow operating window, but it should be all I need and reduce the cost/ amount of batteries required. Anything more seems like it will make changing gears too difficult, and may not respond correctly to an emergency brake input (like adding a gear change delay). The trailer roof should have space for 2-300W of solar panels and the tow vehicle already has a 100W panel that isn't being used to the full.

ROI, I'm not a hypermiler for the monetary gain, but tax law (AU) lets me claim fuel based on distance traveled at the EPA rating, so it's a bit like double dipping, $$ saved at the pump and an 'additional' tax break. It's also a lower stress way to drive, it doesn't really matter if someone tailgates and rear ends the trailer.

Looks like I'll need 12kWh of batteries for a day's driving, that's about 10 lead acid batteries, but of course ideally, something lighter. The solar panels will provide a realistic 550Wh while parked during the day between commutes.

[EZP 545]

Hi, with reference to using rc motors, I have seen one used on a scooter, with a brushless sensorless controller, this ran with some growling and roughness, until it synced in with the controller, letting the throttle off a bit helped this transition, and then it would run ok.
So it didn't like the starting torque, but then settled down.
My exploits with priuses has grown to a Hybrid Toyota Coaster bus, which is now operating in an electric only mode for up to 60km ( max is probably 80km) but the original ic motor and 25kw generator are available to prevent deep discharge.
The wood gasifier to electricity converter that I have on a trailer will be utilized for this.
Regards George