Range-extender Sidecar for EV motorcycle
 

Last week, at a local showing of WHO KILLED THE ELECTRIC CAR?, one of the questions from the audience was if there are any hybrid motorcycles out there.

I briefly spoke about my electric motorcycle conversion, but mentioned that its a bit difficult to cram a gas engine, electric motor, batteries, and everything else all within a motorcycle frame.

I have seen photos of several "range-extending" trailers for automotive EV's.

Why not a sidecar for an electric motorcycle? Instead of space for a passenger, it could carry a generator. Ideally the generator would run bio-diesel or some other renewable fuel.

The only trouble is - I have never ridden with a sidecar, know little about generators, and don't have a clue as to how to hook it up without frying my controller!

That's where you guys come in. I'm sure that with guys like Mazda Matt, Wherewolf, and MPaulHolmes, we could create the Ecomodder EV-Extender Sidecar!

In the end, the electric motorcycle with sidecar would have similar specs to GM's Volt.

Of the list of suggested names for Paul's open source controller, I rather liked "Open ReVolt". As a less expensive (and cooler!) alternative to the Chevy Volt, the name would fit perfect. Motorcycle culture always seems to go for the bad-boy attitude. Maybe I could paint a skull and crossed lightning bolts on there!

So go ahead, let loose with your ideas, concepts, and encouragement! :thumbup:

side cars are hard to set up so they handle well as you have the same kind of alinement problems you get with a car, only it's on a semi-removable part of the vehicle, not an easily removed part of the vehicle either.
Side car motorcycles are also normally designed to have a side car, something like the Russian made Ural, where their front suspension is set up differently so they handle better with that 3rd wheel.
I would say get a motorcycle trailer, it would also work with your metro if you had a hitch on it, they tend to be small, light and let the cycle lean in turns, you can also un-hook it for short trips.

Whatever it is, it must be completely teardropped! That would be pretty slick looking.

Not knowing much about motorcycles I can't comment much on the dynamics of riding with a sidecar, but just seeing what Ryland says I must agree that it sounds like a trailer would be better unless you can come up with a new bike.

In for more, :thumbup:

one of these?

Uni-go Trailers Texas Plus

Might be nicer than a sidecar if you make it out of an old 250cc scooter. Sidecars suck for any riding speed other than slow. The one time I rode a bike with a sidecar I hated it. A tilting trailer will solve a lot of the annoying problems and just leave the one big annoying problem of making a hitch for it.

http://www.uni-go-trailers.com/front%20page%20image.jpg

I've seen the bob style trailers for bicycles and heard really good things about how they handle due to their single wheel and low center of gravity, a hitch should be pretty simple as it would only need to swing up and down, the side to side hinge would be farther back, but if you did go with a standard style two wheel trailer there are already hitches avalible for motorcycles and as I pointed out above, you could adapt it to work with all 3 of your electric vehicles.

Hey CoyoteX, those are some nice looking trailers.

I love the style of sidecars, but they do sound like a pain to attach and detatch.

The pricing on those trailers above is more than I spent building EITHER EV. Building something real similar from a scooter sounds like it might work well. I have also heard good things about bicycle BOB trailers, and have always liked the style of single wheel trailers.

I would think that to design a trailer that could go on either the motorcycle or the Metro, it would just require a little thought put into some sort of custom hitch and have the wiring connections the same on the car and cycle.

Does anyone have thoughts of how to run the electrical from a generator to the batteries for use while an EV is moving?

It seems that perhaps having a commercial generator with a 120AC outlet on it could have the battery charger connected directly to, and then the power of the carger goes to the batteries and motor.

The motor would draw however much the charger is providing and the rest from the batteries.

That would also let me use a gen-trailer with either the cycle or car, even though they run different system voltages.

What would be required to make it all work without frying the controller or the battery charger?

I know they say the Volt's generator does not charge the batteries. They say it was an inefficent use of the gasoline. Go figure.

Maybe - It's not automatic, but i'm not an electric kind of guy.

Generator with adjustable voltage regulator for your different vehicles.
Have main disconnect switch for the battery bank.
Disconnect batteries then start the generator.
I would think the controller would treat it like turning it off then back on again.

You man be able to have an AC output so you can do a little charging of main batteries when at stop lights/coasting.

Good luck
Don

Thanks for the kudos... I'm going to need a new hat :)

I think I'm siding with the above suggestions - sidecars suck. Never even driven a motorcycle and I still think they suck. Esthetically, they are ugly. Practically, they seem like they would be a pain to maneuver compared to a bike with a trailer, or a car. Geekilly - they increase your frontal area for wind drag.

I didn't know that the Volt did not charge the batteries. That's interesting. I suppose if that were your design criteria, then you just need to price out a generator that can provide enough amps to accelerate your car on a hill at your system voltage.

I work on one device that is both 120AC and 24VDC powered (the battery is backup in case of power failure, the board actually runs at 12V after a power regulator. When the device is plugged in, the AC side of things provides about 3 volts higher than the battery. This way, the battery recieves a "constant voltage" charge, which may not be greatest, depending on your batteries.

I rather doubt that your battery charger could do anything useful... it takes 6 hours to charge what it takes 20 minutes to use. Otherwise, that'd be a great idea.

Interesting project you've got going here... making it compatible with both the bike and car is certainly tricky...

range-extender
 

I'd do trailer,and take all my cues from Craig Vetter's build thread.There's a fella in town with side-hack.It's just too weird!

A broken used Chinese scooter in the 125cc range can usually be had pretty cheap. Usually from what I have seen if the motor makes it a hundred or two miles it will hold up for a while. But the chassis is pretty much always crap so expect to see terrible wiring, bad bearings and broken welds. That just means it will be a good price and still work for what you want it to do :)

Find one with the motor and all of it built into the rear suspension and it would be easy to cut away all the extra frame junk and make a u-joint hitch for it. I guess a rc car servo could be used for the throttle and connected to your existing electric throttle. I would probably just forget about the scooter brakes since your bike brakes should be ok. If you have a servo system for the throttle a trailer plug could get everything working. Park/brake light, start, throttle, and ignition kill would be all it needs I would guess.

The motor is pretty small so if you do fiberglass or whatever to make it aero it would also give you some storage room. I am not sure how much air it would need for cooling but that can be figured out from how much it gets from the existing scooter body.

I would worry more about your charger then your controller, if you try to drive and charge at the same time, but either way I think it will all be fine, you have the battery pack as the buffer.
If you are talking about a pusher trailer... then I would not do that with the motorcycle, to unstable! yes, it could be done, I'm sure but there are alot of things that could go wrong as well.
I have also thought about making a simple battery trailer with extra batteries, this would work for any electric vehicle and make the electric motorcycle alot more fun for short trips as you could leave it home and have the cycle be lighter weight, or make a really small light weigh electric motorcycle, or moped even and have all your batteries in the trailer.

Ben, I have been thinking the exact same thing for when I finish my bike. Check out renewable energy shops, there are generators made to directly charge DC batteries at different voltages for when solar/wind powered systems aren't putting in enough juice. I can't remember if you are running 36 or 48V but there are definitely options out there... here is a 48V 60A Australian option I was looking at. It would cost more than my entire build but i'm sure there are other (cheaper) options too. It would make for the perfect range extended EV without having to carry the extra weight when its not needed.

Here's another one for half the price. This could just connect in parallel with the batteries, when put under load (>60A) by the controller the voltage would sag until the batteries started putting in amps to the controller too (up hills etc). When the running load was <60 amps some of the excess power would go into recharging the batteries again. Going to mains voltage AC then back to DC in the charger would be fairly inefficient and you wouldn't get anywhere near the 60A that these DC generators can put out unless you had a super beefy charger.

Do DC generators generate DC, or do they generate AC and convert to DC?

Ben... What's your goal? Cross country trip? Or cross county trip?

Right now, the motorcycle will go 30 miles on a charge, IF I drive 25 mph.

One client I work for a lot is 28 miles away. I would like to get there and back on a battery charge and a little fuel. Charging while there may/may not be available.

Even if charging were available, my current charger is VERY SLOW, and I am not interested in purchasing a more expensive charger, when there are still too many places I wouldn't be able to plug it in anyways.

If I were able to do 60 or 70 miles in a day (at maybe 35 or 45 mph) as a hybrid, that would be great!

They generate AC and rectify it.

Maybe a battery trailer is your answer, then? You have 4 batteries @ 48 volts right now?

How high can you bring the voltage? I'm just thinking, if you can get 8 batteries on a trailer, you've got 72V in 2 strings. This will bump up your speed and your range and still allow you to do your "light" driving without the trailer.

From what I've seen, generators that are useful cost more than you're spent on your entire EV adventure.

Then we might as well ignore DC generators. If a generator is the answer, use an AC generator and:
a) a transformer to up/down the voltage so that you can rectify it to a few volts above pack and add capacitors
b) rectify it, run it through a DC-DC that will give you a few volts above pack.

If charging the batteries is not going to happen, you can use a diode between the generator's massaged DC output and the battery pack. It will draw from the generator till it can't keep up, then draw from the batteries. When load is low, the generator will ease up.

Generators are almost always alternators and produce AC because they are more efficient even after rectifying it to DC.
If I was to build a trailer I would want something that would give me a 200 mile range as it would allow me to get to more car shows with my electric car and to larger cities that are around me, but my personal needs are around 10 miles per day.

I can't see that working unless you're drawing less than 2k watts at whatever your desired speed is.

Ryland's example seems to be a good one.

Have an all-electric vehicle for day to day local use, and hitch up a trailer to turn it into a series hybrid if you need to go farther!

So we are back needing a motor to push the motor cycle, but is this 125cc strong enough to push the Metro, or is it better to get a bigger pusher trailer and then is it too strong to push your motor cycle.:confused:

Nah, I am really MUCH more interested in a "series-hybrid" trailer.

If I wanted a small engine to push my motorcycle around, I would just get a gas motor.

I am really interested in a generator set for occasional use range extension. Ideally, it would run on biofuel as well.

Using scooter or motorcycle parts to build it would be slick though.

Mr Sharky's pusher trailer was made from car parts that match his EV car. I always thought that was pretty neat.

Have you asked on EVDL? I'm really not that sure how you could go about this. Maybe I could run the question by our power electronics guy...Do you really want it to be compatible with both your bike AND car, or is that just a "nice to have" if it is possible?

Step one, Ben... go price out generators of the required kW rating. Presumably, you want to be able to run forever with enough gas, so you need a gen that will produce the same wattage as you are used to driving with.

It would be NICE to have something that could work with the car AND the motorcycle, but I am more interested on extending the range of the cycle.

The cycle uses less amps to run and has bettery batteries on it.

Since I actually don't know exactly how many amps the cycle pulls, the FIRST thing I would really need to do is put an AMMETER on it! :thumbup:

I know I've recommended it to you before, but I just have to say that I still really like my PakTrakr gauge, I have the amp pickup for it as well so the gauge can tell me how many amps, or KW the motor is drawing, it also gives me voltage of each battery and some nifty real time visual display of battery voltage, does all that stuff that a scan gauge does, only for electric vehicles, and the few issues that I have had with it have been taken care of without question.

Otherwise if you check on Ebay you should be able find a cheap DC clamp on amp meter, we have one that works great and I think was about $40.

Also figure out your average speed and how many miles you go on a charge and how much energy you use in that time, because unless you are doing alot of highway driving you are going to have stop and go and time to charge while waiting at stops.

Maybe I will have to start saving for a PakTrakr.
It does look suspiciously like a ScanGauge for EVs

Ben, maybe I'm crazy, but you could probably get an idea of your power consumption by simply timing how long you are out on the road and checking to see how many kWH your killowatt reads. kWH/H = kW. That gives you a running average, which is fine if your generator will actually charge the batteries.

The only issue iwth that is that you'll be using the bike differently when it has a trailer, and drawing more amps from its weight. So take that kW rating and double it to be safe.

Look up weights on generator sets for your power consumption. Diesel ones are going to be heavy. Make/borrow a small trailer & weigh it down to the approx. weight of the generator & stuff needed. Now measure power consumption. Repeat.

FLEXIT leaner sidecar
A possible variation on the side car apparently there are other variations out there.

I got a call back from the guy at Electrical Rebuilders, they do starters,alternators, generators etc. They do a lot of work on busses, firetrucks, etc.

He said they can build 56V generator systems, I would just need to hook an engine up to it.

Unfortunately the setup would be about $1000 for the generator!

I don't mean to start this back in another circle, but since you're just looking to EXTEND you mileage, how about a small diesel engine running one of those windmill generators???Something homemade, working like the one mattW suggested that makes 60 amps or so, will extend your range on the bike a lot. EBay has the generators, and some small diesel engines, at times...

If Boss Hoss can fit then I beleive Hybrid can fit :)
 

if a V8 and a turbo 350 tranny can fit there is no reason a hybrid cannot fit?? The Boss Hoss setup is bigger than the whole Prius setup http://www.alumrad.com/BossHossRad.JPG

6000 WATTS SILENT DIESEL GENERATOR REMOTE ELECT START! - (eBay.ca item 280341809386 end time 14-May-09 12:20:04 EDT)

Click the link for 6KW EPA approved diesel generator for under 1000 dollars. It has 120/240 output at 40/20 amps. It even has a 12V output at 8.3A for your accesories!

That all sounds well and good, but can the bike handle towing a 370lb generator on a trailer (likely another 80 pounds, minimum)

Howdy, while a sidecar motorcycle is not the easiest thing to drive, however it does offer advantages, 8 maybe even 10 batteries total for one, along with storage of things if you mount/build a box above the batteries, and it can go in the snow, at least as long as the roads have been plowed, I drive one in the winter here in madison wi. I have been driving a homebuilt sidecar on a BMW motorcycle now for 5 years, and am waiting for the Revolt controller to be available so I can build another bike/sidecar combination with electric drive. be careful of a push trailer, the DOT may chase you for a license for a car, if you have four wheels.

how about one of the little gensets and a charger? 'bout $125 for a 1k gen::


ETQ Portable Generator — 1200 Surge Watts, 1000 Rated Watts, Model# TG1200 | Buy now for just $124.99! 15X16X13 size. northern tools

Trailer and side car offer the same advantages, except that a trailer is more aero and a sidecar is probably easier to park than backing up a trailer on a bike.

You need to size the generator to be able to output the average power usage of the bike. So assuming that range extension means he's going on a long drive, then it has to provide power equal to the bike's consumption at speed. If ben could find a small trailer and load it up with cinder blocks, he could drive till the batteries are down, time how long it takes, then meter the electricity required to top off the batteries. power usage in kWh divided by the run-down time gives you the kW required to drive the bike, on average.

I put together a series hybrid range extender for my electric bicycle, see here:

Series Hybrid with Hubmotor - MotoredBikes.com: Motorized Bicycle Forum

You could do this pretty easily.

A 2 kW brushed permanent magnet electric motor (or a little bigger) with rated voltage at about 80V - 100V at around 10,000 rpm. You want to get about 10 - 20V over your rated battery voltage at the highest torque rpm of the gas motor (below).

A 5hp gas motor, preferably with a governor.

A coupling to tie the output shafts together.

A switch to connect the dc motor output with the batteries.

Adjust the governor rpm to output about 10V over your battery voltage.

When you run it under load, it is self regulating because your amp draw is more than the motor can put out. When you are idling, it may fast charge your batteries but only when you have no load on the electric system. Just make sure your max dc generator output is lower than your controller can handle.

I'm thinking that buying a generator may be more fuel and power efficient than buying an engine not intended for use as a generator and a DC motor not intended for use as a generator and coupling them. I also think that a rectified AC would be better or else your DC motor will be trying to turn over the engine when the engine isn't running (this could be solved with a bigass diode, though).

The dc motor will start the gas motor when it is switched on. This allows for easy control of the hybrid system, just switch it on and it provides power. You need a good coupling to do this.

A three phase motor (rectified) is more efficient (I believe) and probably lighter weight for the same power output but will not do the auto start that the dc permanent magnet motor will do. If you have another way to start the gas motor, or just leave the gas motor running all the time, a three phase generator would be preferred. You could also use a belt drive if you did not expect the electric motor/generator to start the gas motor.

Permanent Magnet Alternator Wind Blue High Wind

A gas motor of the typical Briggs and Stratton type will do fine as a generator motor.