Build Your Own Electric Motorcycle by Carl Vogel, , available at Book Depository with free delivery worldwide. Image Notes lesforgesdessalles.info Image Notes 1 .instructables. It's not worth trying to make your own. http://www. Just buy the. How to [and not to] Build an. Electric Motorcycle. Zachary Rubin. Page 2. Why Build an EV? □ Gas is Costly. □ Electricity is win. □ EcoTard. □ Coolness factor .
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If you are interested in building your own electric motorcycle, but want even more .. I simply made my own paper template based on the PDF file that I already. Build Your Own. Electric Motorcycle. Carl Vogel. New York Chicago San Francisco. Lisbon London Madrid Mexico City. Milan New Delhi San Juan. More importantly, he is writing a book called Build Your Own Electric Motorcycle —stay tuned!! Steve Clunn assisted with the book and is an electric vehicle.
Compound DC Motors. Very well done, well laid out, and just repetitive enough to inform the way something previously stated applied to the current step. She has been so supportive of the book and also so great with her entire team of copy editors and proofreaders. Which will give more efficiency.. They custom make them on CNC equipment and send it to you in the mail. Everything else should also work on the cycle, the light, horn, turn signals, etc.
This is how I built an electric motorcycle. I just read the user's manual and learned as I went. You have to match your controller to your voltage but the amperage is up to your budget.
The following instructable will not give you exact step by step instructions. With a top speed of over 70 mph and 10 miles per charge. Custom electric motorcycle logo made by my brother. I've always wanted a motorcycle and decided that making an electric motorcycle would be a good EV project. Don't waste your time trying to build a potimeter on an old throttle--just buy a pre-made one and be done with it. You'll want to get a fuse that matches your setup.
I ended up getting the D51 model. I went with 6 Yellow Top Optima batteries from remybattery. I ordered it online thunderstruck-ev. You have to match your charger with your voltage but the speed of charge in Amps is also up to your budget. Components and tools Every motorbike is different but the basic components can be the same.
This is a device that you hook up to your existing key ignition on 12Volts and it will close the loop so you get the full power to your controller. And the bike didn't run.
Why and how I only work 3 miles from home but with gas prices getting out of control. It seems that there are only two real choices: Alltrax or Curtis.
A little knowledge of motorcycle maintenance wouldn't hurt. I got the Magura K Twist grip throttle from cloudelectric. Craig's List or ebay motors.
I looked at many different bike styles and decided on a Honda Interceptor for a few reasons: Thanks Ned. After making cardboard mock ups of the D23 model I realized that there was no way six full sized batteries would fit and still look good. This may take a long time to pay off in gas savings. I purchased a Sevcon 72V Input Check out the photos at the bottom to see what I bought and the EVAlbum for other electric vehicle projects.
This project took about 3 months of research and development not counting waiting for parts to come in or help from a friend with the welding.
You'll have to decide for yourself. How to build a 72Volt electric motorcycle No gas. I highly recommend battery terminal covers for safety. Below is a list of the parts I used and where I got them. I thought it would be great to have an electric vehicle. After reading other EV bike specs and knowing that I wanted to go faster than a moped. As an added feature I wired up the ignition switch to the neutral indicator to show me when the bike was on.
Other parts Wire. So don't yell at me about trashing a perfectly good motorcycle. Bought on ebay motors in non working condition. This meter has multiple settings but I only use the volts. Additionally a volt meter. Image Notes Image Notes 1. Just buy the throttle. Alltrax makes a very nice speed controller with configuration software. It's not worth trying to make your own.
After you get your motor mount and battery compartment all welded up. Remove the gas tank and using your grinder or other cutting tool to cut out the bottom.
The last thing he did was weld in metal plates for mounting my electrical components. Next he fabricated the battery rack and gave each battery a swing arm closure to give a tight fit yet still allow me to get them out easily.
Take a look at my pictures to see how I fit everything. I had a friend weld it up for me and he did a fantastic job. Make sure all gas is out before cutting Reference your owners manual so that you don't cut any necessary wires.
This makes room for extra batteries or components. The build Start by removing all of those nasty internal combustion engine parts. Then I used some metallic gray and black spray paint. Now for the hard part. This makes a world of difference and costs very little. You need a secure battery box and motor mount. From the photos you can see that he first strung up the motor to allow for minor adjustment to be made before cutting the motor mount plate.
Two wires in. After that was cut he made a nice chain and sprocket enclosure with a door and welded them onto the frame. If you have the money get one good charger instead of trying to use multiple smaller ones.
I made a fake gas cap and ran the power cord from the charger up the frame and out the top. Now that you have all of the welding done and your frame looks great. I removed any rust spots and chipped paint that I could find. Half inch foam padding spacers are between each battery to help cushion the stack--but believe me.
Used thin rope to hold up the motor in just the right spot. Moving six cardboard batteries is a lot easier than real ones Image Notes Image Notes 1. Battery rack has removable pins on each one to allow for a more snug fit and for easier removal of batteries.
Motor mount welded in place measurements could be made. Optima batterys are sealed so they can be positioned in any direction. Sprocket and chain cover door swings open for easy maintenance. This diagram should be pretty accurate to how I built mine. Wiring If I tried to explain where to connect every single wire I would get writers cramp.
View the wiring diagram that I put together and let me know if you have any questions. Wire wrap makes things look professional. Speed controller 2. Albright Contactors SW gets 12 volts from system and allows you to use 1. Battery connector covers make things look nice and keep you safe. Emeter 72V prescaler 4. Lock washers are a must. Shunt 6. For more photo's and a build commentary visit my website at http: Did my own prep work to save money but had them professionally painted.
I wanted my bike to look as good as it rides. It will give you readings for Volts. Here is the E-meter nicely installed where the rpm gauge used to be. I know these weren't step by step building instructions. Be prepared for the dealership mechanics to swarm and hit you with a bunch of questions and jokes about failing the emissions test.
My intention was to give you the motivation to build your own by seeing how I did it and make it easier by supplying the parts list and a wiring diagram. I got the bike inspected and insured. Last few things Double check all of your connections and tighten every bolt.
Hours left and Time left. Using a serial cable and laptop. If the amount of electricity used was the same wouldn't I get better starting power and top end speed? Sep I don't see how a transmission will really help. A typical motorcycle and rider going mph will need about 5 horsepower to maintain that speed on level ground. Using a tranny will allow u to run the motor at a low amp rate at higher speeds using less juice form the batteries.
To go faster u run the motor at a higher amp rating sucking more juice from the batteries. Aug 9. Oct Kind of off topic.
I know dillweed2 says: Stryker says: Horsepower by definition is RPM x Torque. The trans would also be extra weight and require more energy to overcome the drag from turning a trans bearings and gear lube. A transmission is just one more thing loading down the motor. Drag is dependent on velocity-squared. Electric motors due have a tendency to overheat and melt electrical components. The weight wouldn't be that much. I think you should definitely add a transmission.
The electric motor will run at a slower speed with a trans. If you are trying for highest efficiency and longest range. If properly designed. A transmission would provide a better "holeshot". Electric motors are not like a gasoline that requires more fuel at higher speeds. If you are designing a DRAG bike.
Direct drive like this is something better suited for motorcycles. The higher the voltage. Silence says: Jul There are MANY currently available. But I'm no electrical engineer so I doubt I could answer it if I did understand. That is one reason why AC power is transmitted over the grid at very high voltages and then stepped down locally. I just herd about it.
Wiring in parallel pos to pos and neg to neg is how you jump a car battery. A motor could be designed to use 12V A. That's why electrical companies transfer power in thousands of volts.
When designing the system. Its optional but in the end it comes down to extra weight. If I ever need to adjust the position of the motor side-to-side, I can loosen the nuts on either side of the plate and move it one direction or the other. This motorcycle is powered by four off-the-shelf batteries. They are Optima Yellow-Tops , rated at 55 amp-hour capacity, and cranking current of nearly amps. They are AGM - absorbed glass matt. That's a style of lead-acid battery that is sealed up and the electrolyte is soaked into coils of fiberglass matting.
They cannot leak, spill, or slosh around. While there are other types of batteries available, this seemed to be the best combination of price and performance for my project. Besides being challenging in adding water, the movement and possible tipping-over of a motorcycle would not be good for flooded batteries.
Sealed lead-acid batteries VRLA would also be fine, as would gels. However, neither of those can crank the power as well as an AGM can, which is what gives the cycle good acceleration. Lithium batteries are excellent for weight, capacity, and power, but are currently only for those with higher budgets. If you use lithium batteries, everything else about the project is the same, except for a different battery charger and a battery management system. Figuring Range Going back to some simple math, we can get an estimate of motorcycle range.
I have four batteries, each of which is 12 volts, but they are wired up in one series string of all four of them, so it's really 48V in total. The batteries are rated at 55Ah.
Of course that does vary by weather, speed, riding style, etc. But this is just a rough estimate. Will it perform the way I want it too? I only live a couple miles outside town, and the next town is ten miles away.
I can use this cycle to drive all over locally, and head to the next town over and back on one charge. In real-world driving tests, the single-charge range of the cycle came to 23 miles if I drove full-tilt, and 32 if I was doing easy acceleration and in the city 25 mph zones.
I like to think of this as the poor-man's C. If you are into computer design, there are many great programs out there to help you create 3D images and think in three-dimensional space. Google Sketchup seems to be getting fairly popular.
Still, you really can't beat an actual, physical object in your hands. I just prefer something that weighs less than lead. In my earliest version of the cycle, I had three batteries in it.
Then I moved up to four for more range and higher top-speed. I was never sure how to fit four inside the frame in a way that fit well and looked good. By using cardboard mock-ups, I was able to experiment with various arrangements of batteries until I found one that I liked. In this case, the fact that I could mount these batteries turned on end allowed me to come up with a configuration that I liked.
Once the size and number of batteries are decided on, they need to be physically mounted inside the motorcycle, and solidly connected to the frame. Please note - Battery technology has been changing rapidly the last few years, largely in thanks to commercially-built electric cars. At this point, if I were building an electric motorcycle, I would go directly to lithium cells. Please visit a web forum for the latest availability and best practices with Lithium Batteries.
Rack 'em up! The batteries need to be securely mounted to the frame of the cycle. This is typically done with a box shape or angle iron. You do also want to keep in mind that the batteries are the heaviest part of the motorcycle.
Fortunately, that describes the big hole left by the removal of the engine and transmission. The trick is to design a rack that fits in that space and holds the batteries. A simple start. In the earliest, experimental version of the motorcycle, I played around with something as basic as a "tray" put across the bottom two frame members. Small batteries could just sit right on top of that in a single layer.
The larger batteries could only fit two there, so the others would have to be mounted in some other way. I experimented with "unistrut" - a slotted C-channel material available at building supply stores. It worked well in holding the batteries, but I didn't like the looks. The batteries stuck out the sides a bit in a way I didn't like. Cut, Grind, Weld, Paint. While the early version of the cycle was functional, I really wanted to get it cleaned up and looking nice.
I had been practicing welding, and it was time to build a welded rack to hold the batteries. The rack consisted of 1" steel angle, cut to make frames that fit around the batteries, and tabs that would reach from the battery frame to an existing engine mounting point on the frame of the motorcycle.
It would be made of several "layers", because of the arrangement of the batteries - two on the bottom, and two mounted above them. Essentially, there were four pieces:.
Besides just being a square ring under the bottom two batteries, the bottom piece also had to directly connect to the bottom of the frame. To do that, I ran two pieces of angle iron the length of the cycle's engine bay, so that it bolted right to the frame, again, through existing mounting points. It might be a little overkill, but gave me plenty of new attachment points for threaded rod to hold down the batteries, and another connection point for the motor mounting plate.
To figure the size of each rack piece, I simply put the batteries together the way they would fit, and measured them. I added just a little more to the measurement to give me some wiggle-room, and account for some thin weatherstripping to go between the batteries and rack when finished. The tabs to mount the battery rack components to the frame were just flat steel - 1" wide. I put the batteries and rack parts into the frame and test fit the spacing between the rack and the frame and clamped them in place.
Then I removed everything and welded the tabs. On the back of the rack parts, I welded some short bits of steel pipe, just a little larger diameter than the threaded rod I was using.
These are "holes" that the threaded rod goes through to align all the parts and sandwich them together. All rack parts were were painted with Rustoleum gloss black paint and the assembled into the cycle. The finished rack looks nice and holds the batteries securely. The battery arrangement keeps them inside the body of the cycle. I was originally hoping to be able to just exactly clear the gas tank. In the end, the pieces of angle iron added up to too much total thickness. I notched the edge of the gas tank to make it clear the top batteries.
The gas tank is hollow and covers the top posts of the batteries. If you have batteries, you are going to need to charge them. Chargers are fairly simple, but there are a few things to think about. Will you use one 48V charger, or 4 12V chargers? Will the charger mount on the cycle, or will you keep it in the garage? What about solar or other ways of charging? It would be pretty simple to hook up one twelve-volt charger to each of the four batteries.
Or even just use one 12V charger to charge a battery, wait for it to charge, move it to the next battery, wait for it to charge WAY too time-consuming though In my setup, the top two batteries aren't real easy to access to connect and disconnect battery chargers to. There is some space under the hollowed-out gas tank, that could fit a battery charger. You simply connect the positive cable to one end of the string of batteries, and the negative cable to the opposite end of the string of batteries.
Higher voltage chargers tend to be more expensive in general that 12V chargers They just mass-produce so many 12V chargers that they are cheaper. However, 48V is a common voltage for golf carts, forklifts, and electric scooters. Ebay and on-line electric scooter companies are great places to get 48V chargers. Onboard vs Offboard Where do you want your charger to go? My original 48V charger permanently mounted on the motorcycle, under the gas tank.
It's plug was right on the frame of the cycle, and I would just plug an extension cord into it from the wall. The cycle would automatically start charging. A charger that's left always mounted to the vehicle is called an "on-board" charger. On the other hand, you might have a charger that you just leave in your garage.
It would have either alligator clips similar to jumper cables or an Anderson disconnect a popular, fairly standard power quick disconnect.
When you park the cycle at home, you either plug in the connector or clamp on the alligator clips from the charger to the battery pack. Both on-board and off-board chargers have their benefits. On-board chargers are always with the vehicle. If you ride over to a friend's house, or have access to an electric outlet at work, you can ride there, plug-in, and charge the cycle the whole time you are there. Your charger is always with you. You can top off the batteries any time you want, even if they are just partly discharged, or even if you know you will only be charging for a little while.
This is called "opportunity charging", and is a good way to extend your range and keep your batteries happy. An off-board charger is NOT with you while you are out and about. That can be a good thing too.
While you can't "opportunity charge", you also don't have the weight of the charger, nor do you need to have the SPACE on your cycle for the charger. In addition, some chargers are rather large and heavy, and you simply wouldn't want to try to lug one with on your motorcycle. You might also be able to get a really good price on purchasing an off-board charger. Also, an off-board charger is typically available for use on other things, such as recharging your car battery. I originally started with a very compact 5-amp 48V scooter charger that I kept on-board of the cycle.
Unfortunately, it was a poor quality off-brand that eventually quit working. After that, I put an Anderson disconnect on the cycle so that I could quickly connect and disconnect a variable-voltage off-board charger. That charger is big and heavy, and stays in my garage. It is variably voltage, so I can charge anywhere from volts.
When I am not using it to charge the cycle, I can charge my 12V car battery, or my 36V electric riding lawn mower. If I upgraded my motorcycle to 72V, I could still use the same charger and just turn the knob another two clicks! How big of a charger? People commonly ask how long it takes to charge an electric vehicle.
Or the may ask how "big" my charger is. What they are really referring to is the rate of charge, which is measured in amps. Battery capacity is measure in amp-hours. When you want to know how long it takes to charge a battery, it depends on the capacity of the battery and how far it is discharged and the amp rate of the charger.
The basic math is pretty simple though. Lets say that you have a battery that is rated at AH, and it's half-empty. That means that you need to charge it with 50AH. If you have a charger rated at 5 amps, that will take 10 hours, or overnight. If you have a amp charger, it will take 5 hours to charge, which might mean you could get a full charge while at work!
Consult your battery information. Battery manufacturers provide information on the preferred rate of charge and voltage points for their batteries. Get a charger that matches what your battery manufacturer recommends. In addition, some chargers are either pre-programmed or have a specific setting for a particular type of battery. If your charger has a setting for "Flooded" and another for "AGM", make sure you use the correct setting.
Mine are rated at 55AH, so a 5 amp charger will always recharge it in 10 hours or less. I'm now using an off-board charger which is selectable between 5 and 10 amps. I added an Anderson connector to the battery charger and the motorcycle to make charging as easy as plugging in the connector, and flipping the charger switch to On.
There are other ways to recharge batteries as well. With the motor and batteries in place, they could be cabled up, and the motor would spin, but how would you control the speed? That's what the motor controller does. Direct Current DC motor controllers typically all work the same way. They "chop" the current from the batteries to the motor. Essentially, they are a big fancy switch that turns power to the motor on and off very quickly, typically thousands of times per second.
The controller varies how long the circuit is on vs. Besides controlling the speed of DC motors, it's also used to dim LEDs on sports scoreboards and digital billboards, and is also used in many other facets of industry and electronics. The speed of a DC motor is directly proportional to the voltage provided to it. More voltage such as having more batteries in series makes the motor spin faster. Using a modern electronic PWM controller gives an amazing effect of all the power you want at even very low speeds.
There are other ways to control speed on battery powered DC motors. A bit like having "3-gears". These systems made a lot of clacking noise, and the contactors heavy-duty power switches needed maintenance somewhat regularly. The speed control was fairly basic. Vehicles like the Citicar made use of this type of system.
Voltage to the motor could also be controlled by running the current through a variable resistor. Trouble is, you need a BIG resistor! They get hot, and would need a LOT of forced air cooling. It would be a very inefficient means of control, as the only time all of the power goes to the wheels would be when you were driving full speed. The rest of the time at least part of the current is being wasted as heat.
PWM is a nice and efficient means of controlling speed, conserving energy, AND giving you excellent speed control. If it sounds complicated, don't worry, there's a PWM controller in nearly every electric golf cart out there. In fact, a used golf cart motor controller from E-Bay might be a great place to start! Golf cart controllers are typically volt, and are so mass produced, that they tend to be rather affordable.
You will want to make sure to get one that has a high enough amperage rating to make the cycle fun. Choosing a Controller The two most popular brands of motor controllers are Curtis and Alltrax. I'm using an Alltrax AXE controller. Because the motor controller is wired up between the batteries and motor, it is common for it to be one of the limiting factors of your electric vehicle's performance. The model of controller you want will depends on your system voltage how many batteries you have and the current you want to be able to pull.
You typically want to minimize current while cruising, so that you are "sipping" power from your batteries, and in turn have a long range per charge.
However, you want to have high current available to you for quick acceleration half the fun of an electric motorcycle! My motorcycle has a 48V system, so I purchased a motor controller that can run on anywhere from volts. If you want to build a motorcycle at 48V and think you MIGHT want to upgrade in the future to 72V, you could get a motor controller that will operate from V, but it will cost you a little more up front.
My motor controller can pass up to amps of current to the motor. The motor is only rated for amps continuous, but can briefly take much more than that. The batteries themselves can produce nearly amps briefly , but the electric motor simply can't pull that much power. If you just want a moped type vehicle for around town use, a amp used golf cart controller will be fine.
If you want to have good acceleration, get a amp controller. A amp controller should give enough acceleration to keep pretty much anyone happy! Once you get into higher voltage and amperage, controllers start to get expensive. If you built your own, you could have the best of both worlds - a high power controller at an affordable cost. But where would you start?
How about right here on Instructables! In fact, here's a controller anyone can build themselves that's good for up to electric horses. Mounting the controller The motor controller needs to be mounted solidly to the frame of the cycle, near the batteries and motor. It does produce a small amount of heat, so ideally the controller should be either out in the airflow, or if you have an aluminum frame, just pressed right up against that.
On my cycle, the best place for the controller was behind the batteries and above the motor. This kept the power cables short and everything was still easily accessed.
It also shows the controller off nicely, as people often ask me how the vehicle works, and it's nice to point out the various components. I used a scrap aluminum plate to the mount the controller. Aluminum makes a nice heat-sink, and it's lightweight and easy to cut and drill. The controller has four mounting holes on its base. I marked and drilled matching holes on the mounting plate, and attached the controller with typical nuts and bolts. Adding that plate to hold the controller also gave me room on the OTHER side of the plate to mount the "balance of system" components.
Throttle The throttle is a "potentiometer" - a variable resistor that sends a signal to the controller, based on its rotation. I used a Magura Twist-grip , a popular throttle that replaces the right-hand grip on a scooter or motorcycle. On my cycle frame, the original throttle was rusted and the throttle cable was broken. I removed the original throttle and slid on the Magura Twist-Grip. It easily installs just by sliding it on and then tightening a pair of screws to snug it onto the handlebar.
Had my original throttle been in good condition, I could have just connected the throttle cable to a different style of potentiometer, such as a PB The throttle comes with three bare wires, but there are only two connections for throttle on the controller!
What do you do!? Well, since you just mail-ordered this part, you can call the dealer and ask which two wire you use. Otherwise, you can test them with the OHMs setting on a multimeter.
Potentiometers have three connectors or wires. The center one is the "wiper" which changes as you turn the potentiometer. The other two wires are the "ends" of the range the potentiometer covers. One is high and one is low. Connect the Ohmmeter to two of the wires, and twist the throttle and see if the reading changes. When it reads 0 ohm when just connected, and ohms when fully twisted, you got the right two wires. Cut or fold back the third wire and cover it with electrical tape or shrink tube.
Route the throttle cable from the handle-bars, along the body of the cycle leave slack for steering! Polarity doesn't matter, plug either wire onto either connector. Make sure they are on securely. As a safety feature of the controller, if the throttle ever becomes disconnected, the controller shuts down. Wiring up the controller power cables to the motor and batteries is fairly straight forward.
The motor controller comes with a manual that includes the wiring diagram. The Alltrax Document Depot is a great resource for all sorts of information on controllers, batteries, and motors. After the cycle is completely finished and test-driven, you will want to tweak the controller. Some controllers have small potentiometers on the side that are adjusted, and others are computer reprogrammed.
The Alltrax AXE lineup has a computer port.
You simply plug a cable from the controller to your computer, download a small program, and change parameters through a simple interface. On most controllers, you can control throttle response, limit maximum amperage, and control voltage shut-off points. On an electric motorcycle the "feel" of the throttle is based on how the controller is tweaked. Balance of System is a fancy term that refers to "and everything else". In an electric vehicle, you already know about the main components, like the motor and batteries, but it can sometimes be the little things that people don't talk about, and can be the most confusing.
Most of these components are shown right on the wiring diagram, along with their specs. I replaced it with a simple keyed electrical switch. It's a "double-pole, double-throw" switch, which means that it completes two separate circuits at the same time.
That's great, because with one switch, I can turn on both the 12V accessory system and the 48V drive system at the same time. I built a mounting bracket by cutting down a piece of metal from a recycled computer case.
I drilled a hole to mount the key switch, two holes for bolts to mount the bracket to the cycle frame, and painted it black. The switch gets two sets of wires to the back of it, both with small crimp-on ring terminals.
On a motorcycle that has an existing, working ignition key, you can route 12V power from the key to activate a relay that will turn on the main contactor and motor controller. Battery Disconnect The battery disconnect is just a big kill switch. It completely disconnects the batteries from the rest of the system. It's an easy way to disconnect power for when you are working on the cycle, and acts as an emergency backup in case the main contactor ever failed. Since there is no clutch or other left hand control, these are mounted on the left side in easy reach of the rider.
The batteries are connected or disconnected with a removable red "key" plunger. Make sure to get a disconnect rated for high amperage. The full current of the vehicle goes directly through this component.
All battery cables, fuses, connectors, shunts, shut-offs, and anything else carrying current needs to be sized correctly. Since I'm using a amp motor controller, sizing everything to amps makes sense. Main Fuse The bike needs a fuse that will blow and protect the system if anything shorts or otherwise draws too much current such as a blown motor controller. I used a fancy-looking fuse holder with a amp fuse in it. Make sure to mount this in such a location that the fuse is easy to access and replace.
If you want to get really wild, make it so it can be easily replaced on the side of the road, in the middle of nowhere, at 4AM in a rainstorm.
Because you just KNOW that's when you are going to have a problem Main Contactor The Main Contactor is a large, remotely-activated, high-power relay. The contactor is spring-loaded, so that if it no longer gets that small amount of 12v power, it opens and shuts down the cycle. This works well as a safety feature. For example you could wire a switch in series with the 12V power to the contactor from the kickstand. If the kickstand is down, the main contactor won't close, and you can't turn the cycle on.
Pre-charge resistor Most motor controllers require a "pre-charge resistor". That's a way to allow power to slowly go into the motor controller to charge up the capacitors. If power was suddenly applied to the motor controller such as just flipping a switch the capacitors internal to the controller would suck up power almost instantly. Do that too many times and the capacitors will blow and wreck the controller.
If you called the manufacturer for warranty work, the first thing they will ask you is about the pre-charge resistor.
The resistor simply bypasses the main contactor. When the battery disconnect is turn on, current will flow from the batteries, through the resistor, and into the controller. As it does, the voltage internal to the controller will raise to match that of the batteries.
Once it does, you can turn the key to on, which activates the main contactor. The contactor is now a less resistive path, and when you twist the throttle, high current can not go from the batteries, through the contactor, controller, and motor, and drive the cycle. Pre-charging the controller also prevents any arcing internal to the main contactor and prolongs its life.
Ammeter and Shunt The ammeter is a display of how much current measured in amps that you are using at any given moment. Think of it as a real-time energy meter. In general, you want to minimize amperage while cruising to maximize range and battery life but it would also be nice to know how much power you use for burn-outs and powering up hills.
This is usually a matched set. The Ammeter is the display itself, mounted on the handlebars or other location for easy viewing, and the shunt, which is a calibrated piece of metal that the current flows through. Two wires one on either end of the shunt go to the ammeter. The needle on the ammeter varies directly with the amount of current through the shunt. My ammeter is a amp meter, mounted in a hole in the former gas tank.
The shunt is mounted out of the way, near the contactor and battery disconnect. I strapped the gas tank down to a drill press with a hole saw in it to cut a hole just slightly larger than the ammeter. Since the gas tank doesn't hold gas anymore, there's no reason not to cut holes in it and mount instrumentation in there.
A needle sweeping back and forth is easy to quickly read. Although a digital display may be more accurate, it's not as useful and it's difficult to read digital numbers that are constantly changing. Power Indicator Light On an electric motorcycle, there is no engine noise or vibration to indicate to the rider or anyone else that the motorcycle is on. You simply flip a switch, and it's instantly ready to go.
Although the headlight is on when the cycle is on, the rider typically can't see that during the day. I wanted a great big, bright indicator to tell me when the vehicle was on. I decided that a green light mounted towards the front of the tank would work well.
I found some switches, lights, and other components on an old instrument panel. One light had a sign on it saying "Power" and another one had a green lens. Both lights were for AC power, not DC power. I grabbed the components and put together the green lens, the power sign, and removed the small transformer on the bottom of the light socket so I could instead run 12V DC straight to the bulb.
The bulb holder was installed through the gas tank, and 12V wiring run to it from the cycle's 12V fuse panel. Powering the 12V system On a typical gasoline motorcycle, there is a 12V battery to start the engine and run the headlamp and other electrical.
The battery gets recharged by the engine, through the alternator, and it is what really powers all the 12V electrical. Without an engine and alternator, you will need some other way to run the 12V electrical. With a 12V battery If you mostly just use the cycle for very short trips and errands, you could just use a plain, sealed, 12V battery. That battery would need its own charger, so that every time you are done with a ride, the 12V accessory battery gets recharged right away.
The battery will take up some space, add some weight, and you would most likely want the charger for it left right on the cycle as well, using up even more space. It does work, and is simple, but not ideal. The converter is an electronic device that takes one DC voltage in, and gives a different DC voltage out. It's a very efficient way to use a trickle of power from all four of the large drive batteries, convert the 48V to 12v, and run the headlight and other accessories. It's two-inches square by half an inch thick - very compact and lightweight.
This saves considerable bulk and weight over a medium-sized battery and dedicated charger. The output end of the converter takes the place of a 12V battery. The converter provides power to the battery as a trickle-charge, and the battery acts as a reservoir in case you suddenly pull more power than the converter can provide, or in case it quit working.
The headlamp draws 55, leaving plenty of power for the tail-lights, turn signals, and other 12V accessories. The converter already has mounting holes in it.
I mounted it with small screws to the same plate that the motor controller is mounted to. All over these various components serve important roles. Even though the motor and batteries are the first things we think of on an EV, make sure you understand the balance of system to properly and safely operate your vehicle. I bet by now that you want to make the cycle go! So, it's time to talk about the driveline. This motorcycle is about as simple and efficient as you can get.
It's more or less the same as a single-speed bicycle. The motor has a drive sprocket, which connects to a chain, which turns the back wheel.
That's it! Drive Sprocket The motorcycle uses a standard machine sprocket. I simply went to a farm store, which had a decent tractor repair aisle and located parts for the sprocket and chain. These are two parts, bought separately, which allows greatest flexibility in driveshaft diameter and sprocket tooth count. The sprocket and hub had to be welded together. In the earliest version of my cycle, that was the only welding done on the entire project. It was only later, when I had some welding experience that I tackled the welded battery rack.
On the original sprocket, I just had somebody else weld those two pieces together for me. These same parts could also be mail-ordered from a dealer such as Grainger or other industrial supplier. The sprocket slides onto the end of the motor driveshaft, and is held in place by a keyway, square key, and set screws.
Chain The chain is 40 chain from tractor aisle. It is a popular size chain, so there is a wide variety of sprockets that match. Driven Sprocket I did not use the stock sprocket on the back wheel of the motorcycle. Electric motors tend to work best spinning faster than gasoline engines, and geared down a bit more. This gives you plenty of power, without constantly running high current through the motor. There are many on-line motorsports companies that will make custom rear sprockets.
I used one called Sprocket Specialists. You simply tell them what motorcycle you have, what chain you want to use with it, and how many teeth you want on it. They custom make them on CNC equipment and send it to you in the mail. I got an aluminum sprocket for a Kawasaki KZ for 40 chain and 72 teeth.
It has a black protective finish. The larger aluminum sprocket weighs less than the stock steel one did. Saving weight is always a good thing for electric vehicles. I removed the rear wheel, unbolted the stock sprocket, and replaced it with the custom one. Consult the cycle's repair manual to make sure to bolts are torqued correctly, and that the back wheel is re-installed right.
Somebody asked about the sprocket being aluminum, and that this is a high-wear item. The black finish on this sprocket is a wear-resistant coating. The sprocket manufacturer highly recommend at least that for protecting the sprocket. I've been very happy with it, and wear on the sprocket has been minimal overall. It would have given me a higher top speed, poorer acceleration, and cause the motor to draw more amps. Most of my riding is in the city, so I would gladly have a lower top speed in exchange for better acceleration and less amp draw.
By having the larger rear sprocket, I can always change out the inexpensive front sprocket to change gear ratios. If I kept the smaller stock rear sprocket, I wouldn't have had that flexibility. My current setup is a tooth front drive sprocket and a tooth rear driven sprocket for a 5. On my cycle, I'm very happy with the combination of range, acceleration, and top speed. On a fresh charge, I have just enough power to do a minor burn-out.
Acceleration away from a stop for city use is very nice. There's no clutch to slip or engine to rev, so the cycle just GOES the moment you twist the throttle. Tweak the Driveline Once I had the sprockets on, I wrapped the chain, checked it for length, cut it to length, wrapped it on to both sprockets, and closed it up for a brand new master link.
Make sure the clip on the master link faces the right direction. It can work its way off if you put it on backwards. The original chain guard still fit over the new larger rear sprocket, but just barely. I simply bent it a tad to make sure it had clearance.
On the front end, the transmission would normally have an integral cover over the chain and drive sprocket. Without the tranny, it meant I had to make a custom chain cover. It could have been made from almost anything - metal, plastic, wood, but I wanted to show off how the cycle works, so I went with plexiglass. I roughed out the shape required with some cardboard and a pencil, and then cut the plexiglass to fit the space.
A straight piece of plexiglass covers the top of the chain. I used a scrap of an aluminum rail as a spacer between the motor mounting plate and the plexiglass to hold it in position. With everything in position. The chain needs to be tightened and aligned as per the user manual. While I had the rear wheel off, I also used the opportunity to put on new tires. Bought on sale during a close-up sale!
Wiring up the power system of the motorcycle is fairly straight-forward. It just requires using thick power cables that are connected with nuts on the motor and batteries, and nuts and bolts on the motor controller. Cable Type You will want to use what's known as welding cable.
Welding cable has many fine strands of copper cable inside. It's designed to carry high current, but it is also very flexible, making it easy to work with. Other types of copper cable are very stiff, may not have the right type of insulation, and aren't as easy to crimp to. Welding cable is available at welding suppliers, good full-service hardware stores, and some building supply stores.
Cable Thickness The thicker the cable, the more current a cable can pass through it without heating up. Cable is commonly rated by American Wire Gauge. Typical household electric wiring for 15 amps might be 14 ga, but electric vehicle cabling might need to be able to handle hundreds of amps.
The motorcycle uses 4 gauge cable. It's thick enough to carry the required current, but still be affordable. Thick cable can get pricey fast.
Lugs Get crimp-on power lugs that match the size of the cable you are using. They are available at the same place you got the welding cable from.
Make sure that the bolt hole in the lug is the right size to match up with the power connectors on the motor, the controller, and the batteries. If the various connectors are different sizes, get the appropriate number of lugs required so that you have enough lugs to fit all system components correctly. Crimpers You will need a mechanical crimper designed specifically for these heavy lugs.
They usually come in two styles - "bolt-cutter", and hydraulic. The ones that look like large bolt cutters long handles, small, jaw, almost always painted red for some reason They can be a bit pricey to purchase. They can sometimes be rented from full-service hardware stores. I borrowed one from a friend. Hydraulic crimpers are typically hand-held with a small cylinder like a mini bottle jack. You pump the handle repeatedly to make hydraulic fluid crush the lug onto the cable.
They have interchangeble jaw inserts for various diameter cables. The can be purchased fairly affordable at import tool stores like Harbor Freight. Making Cables To make power cables for the cycle, you need to know how long each cable is. Measure the distance between the two components using a flexible table measure or a piece of string it's almost NEVER a straight line between anything You might want to account for having cables follow the shape of the frame or all be on the same side.
In general keep cables as short as possible. Cut the cable to length. Thick power cable usually can't be cut with a small wire cutters. A bolt cutter will work fine, but the best tool I have used is a Sears Robo-Cutter.
Any other type of large, sheering cutter will work fine. On the end of the cable, slide on a piece of shrink tube, large enough diameter to go around the lug, and about an inch or so long. Then, cut back the insulation of the cable so that the lug can fully slide on, without having any left over bare wire.
Crimp the lug on with the crimper of your choice. On "bolt-cutter" style crimpers, certain sizes require you to crimp twice. Slide the heat shrink tube forward to cover the crimped part of the lug and the beginning of the cable insulation. Hit it with a heat gun or hair dryer set to hot so that it shrinks into place. Physically connecting the cables Connect all the cables, following the diagram provided in the motor controller manual.
All four batteries in series - one to the next to the next to the next. Batteries to the controller. Controller to motor. Without the main power turned on, the only concern electrically is that the batteries themselves always have power and that anything attached to them can carry current.
Do not touch any power cables to the frame of the cycle, as that is the easiest accidental short-circuit. Wear safety glasses whenever working with batteries and power connections. Once the cycle is cabled up, you only have to check things over and test it all out before you can go for a ride! Testing Before you go for your first ride, you must test the vehicle. Make sure all chain guards and any other safety features are in place.
With the rear wheel OFF the ground, turn on the main battery disconnect and the key. Gently twist the throttle. The motor will start to spin, and along with it, the chain and back wheel. If it doesn't, power down the cycle, disconnect the batteries, and follow the motor controller troubleshooting guide.
It may be something as simple as a loose throttle connection. Most controllers have a troubleshooting indicator light on them to help you. Having an assistant turn the throttle will more easily allow you to inspect the cycle with the motor running. Visually inspect the chain alignment and the front and rear sprockets. Everything else should also work on the cycle, the light, horn, turn signals, etc.
If there is anything else you need to do chain alignment, torque bolts, etc. Test Ride Make sure to take it easy on your very first ride. An electric motorcycle will behave a bit different than a typical gasoline cycle. Empty parking lots and lightly traveled roads are good for your first ride.
As you ride, take note of anything unusual. The cycle should be very quiet and have almost no vibration, other than the bumps in the road. On my first ride out, I noticed that I didn't like the way the throttle responded. It was too touchy. Any tiny twist of the throttle would instantly begin accelerating. When back from your test ride, check the cycle over again.
Make sure nothing has loosened up, that the motor isn't hot, or anything else unusual. At this point, you might want to adjust the controller so that the throttle better suits your riding style. You just built your own electric motorcycle! In the list of "odd things nobody ever tells you about Rear Brake Spring Bracket When I was getting the cycle all back together and testing to make sure everything was working right, I had to hook the rear brake back up.
On a motorcycle, the rear brake is activated by a right-foot pedal. A spring pulls that pedal back up when you release it. But here's the weird part I couldn't figure out where that spring connected to on the frame of the motorcycle. By converting my motorcycle to electric, I no longer had a place to connect my return spring! So, I built a little tiny, custom bracket, just for the spring to go to. On your project, you might come across some other odd quirk like this. It's not a big deal, it just gives you the opportunity to be creative and come up with your own solution!
The Gas Tank Some of the most common questions I get about an electric motorcycle are about the gas tank. Typical is "If it doesn't have any gasoline, why do you have the gas tank? When I got the motorcycle, the tank was already rusted and dented. It was completely bone dry, but I still left it open for a few days before cutting off the bottom with an angle grinder, so I could beat out the dents from the inside. Then I stripped the existing paint, and gave it a new paint-job.
The top part of the motorcycle frame is a tube that goes straight through the gas tank. The tank is almost like a saddle-bag that hangs over that bar.
The tank is also curved and batteries are nearly always big rectangular things. So, between the frame and shape of the tank, you just AREN'T going to cram batteries in there That would also raise the center of gravity on the cycle as well.
The tank does make an excellent cover for over the batteries. It would also be a good place to mount the motor controller or a battery charger, as long as you make sure they have enough ventilation. Some electric vehicle enthusiasts will even make a FAKE gas tank from foam, fiberglass, or plastic. It gives the cycle that cool look, but since it's custom, can be designed to accomodate batteries or other components. Remember, on some cycles today, the "gas tank" really isn't. On Goldwings, the "tank" is just a filler port, but the actual fuel tank is elsewhere on the vehicle.
The "tank" makes a nice box for gloves, goggles, and maps. Should the need arise for my cycle to be loud, I have a horn and am not afraid to use it. Even though most car drivers today have their windows rolled up, with the air-conditioning cranked, and the radio blaring, so they can't hear a thing anyways some people still think that a motorcycle being obnoxiously loud is a safety feature.
After the millionth time that I heard that "loud pipes save lives" mostly from NON-motorcyclists , I wondered if there was a way I could play with that in a way that an electric motorcycle could be BETTER than a gas one when it came to making noise. I connected an MP3 player to my computer and downloaded some various motorcycle sound effects. I then attached self-powered computer speakers inside the hollowed gas tank and bungie-corded the MP3 player to the handlebars.
I could now sound like a Harley, a Kawasaki, a 50cc scooter, or the George Jetson flying car! See details on that here on Instructables. Motorcycle riding is a skill. It should be learned and practiced. Make sure to always "get the hang of it" again in the spring after pulling the cycle back out of winter storage.
Come to think of it winterizing should be covered here as well. Winter Storage When I looked through the cycle manual on winter storage, I was surprised at how much work it was to store a gas cycle for the winter! You have to change the oil, run the tank dry, and doing a surprisingly-long list of other things!
When back out of storage in the spring, you are supposed to change the oil again! On my electric motorcycle, here's how I put it away for the winter.
LED Lighting A vehicle becomes more efficient the lighter and more aerodynamic it is.