Motorcycle NiMH battery pack upgrade –

by Ben N on October 29, 2014

Two weeks ago, I got started on my electric motorcycle battery pack upgrade by tearing apart a Ford Escape Hybrid battery pack.

After that, I was trying to figure out the best way to repack the cells into a size and shape appropriate for the motorcycle. Since I already had the original black plastic battery tray material from the Escape pack, I tried reusing that, cutting it to the size needed.

While working on that, I noticed a few things. One was that there are two different sizes of bus bars used in the pack. That accounts for the fact that every couple of rows of cells, there’s some additional spacing for the bolts that go through and hold the entire pack together. That means that I won’t be able to use an even spacing of the cells in my motorcycle pack design.

Also, the plastic that makes up the original battery tray is really terrible stuff. It’s brittle, smelly, and impossible to cut straight. After making a few cuts to try to create a smaller pack, I also found out that the material is less symmetrical than I thought it was. That means that bolt holes from one piece will NOT line up with those from another.

Back to the drawing board, I’ve seen cylindrical cells mounted through sheet plastic with round holes cut in it. Would this work for my project? Who knows? The only way to find out is to try it. I measured the diameter of one of the cells, and then drew that as a circle on a computer drawing program. I duplicated it 47 more times, trying to arrange it to fit inside the rough shape of the motorcycle frame. That done, I saved the file and took it over to a friend who has a laser-cutter. We put some scrap cardboard in the cutter and used it to carve the holes out of the cardboard.

I arranged the cells through the cardboard template inside a milk-crate (to hold the weight) and saw how the cells were spaced out. Overall, it looked like it should work fine, although without the cardboard templates connected to each other, the entire array was floppy and difficult to work with.

Of course, I really can’t do any EXACT work on the size and shape of the NiMH battery pack without getting good measurements of the inside of the motorcycle frame. And that’s rather hard to do with the existing Optima YellowTops. It was time for them to come out. I set to work taking off the tank, removing the top tie-downs, followed by the electric connections.

After removing the top two batteries, I noticed that I had forgotten how the middle part of the rack also supported the plate that holds the controller, main contractor, fuse, and other important components. I’ll have to support this in some other way when I get the new battery pack in. I removed the bolts going from the middle section of rack to the frame, and was able to get the middle section out.

After that, it was just a matter of disconnecting the power cables on the bottom two batteries before removing them from the frame.

At this point, I now have an electric motorcycle with NO BATTERIES in it. The only thing I can really tell you so far is that it’s considerably lighter and easier to push without battery weight.

So, what’s my next step? Hmmmm. I’m thinking that perhaps I just actually set the cells right down on the bottom of the bike frame. I don’t think it would be too hard to connect them with the bus bars to make a small pack. I could even space out the cells with just some foam or scrap wood for now. A block of cells could be strapped right down to the frame for temporary testing. The next trouble that I see is creating bus bars or cables for connecting the columns of cells together. In the Ford Escape Hybrid, the cells were only in two layers. In the cycle, it’s likely going to be 12 layers high! That’s going to mean MANY more vertical connections – ones that I don’t have bus bars from the Ford battery pack for.


Super-Heros ride electric motorcycles

by Ben N on October 23, 2014


Super-Heros ride electric motorcycles, and so can you.

This summer, I was able to attend the official release of the Harley “Project LIVEWIRE” electric motorcycle at the Harley-Davidson Museum in Milwaukee, Wisconsin. With the crowd cleared from the street, the electric motorcycle ZOOMED up to the museum FAST with a distinct electric motor whine.

To me, that’s the sound of the future, what a motorcycle SHOULD sound like. Of course, one of my first motorcycle memories was watching the Light Cycles in TRON at a drive-in theater. Thirty years later, we finally have REAL (unlike TRON’s computer animated) electric motorcycles, and the Harley is going to be shown off in a big way in the Marvel’s upcoming AVENGERS: AGE OF ULTRON.

A little while back, I saw some sneaked photos from the set, that were highlighting the actors, but what I noticed was the Harley Livewire. Since the AVENGERS preview came out yesterday, we can finally see the LIVEWIRE in action.

Here’s some screen-grabs from 1:27 and 1:34 that feature the cycle. Black Widow launches from an airplane KNIGHTRIDER-style, followed by Captain America doing some slo-mo drifting at 1:34.widow_128 captain_america_134

For me, movies have always been the land of imagination, where the fictional becomes real. TRON really was the inspiration for me to build my own electric motorcycle.

tron_yellow-and_blueNow, we instead are getting not just “product placement” in movies, but clever nods to the real world as well. (I was the only one in the theater who laughed at the joke of Elon Musk’s cameo in IRON MAN 2.) In reality, we’ve had some good electric motorcycles for a while, with Brammo and Zero topping the list. Even electric scooters are going mainstream.

But, if Black Widow or Captain America riding an electric motorcycle gets somebody excited about E.V. two-wheelers, I’m all for it!

I may not be a super-hero, but I gotta say that building your own vehicle and then hitting the road with no engine noise and instant torque is about as close it it comes to being super-human. Not bad for a kid who has seen too many movies.

Batteries to power, turbines to speed. And don’t forget the popcorn.



PS: I’ve also spotted the Tesla Model S several times on the current television version of Green Arrow.



A while back, I ended up at a salvage yard a few hours drive from my house. While I was there to get a transmission, I also ended up walking away with a Ford Escape Hybrid battery pack.

The battery came out of a truck that had been rear-ended, and there was a bit of a dent in the back of the battery case, but not bad. For $150, it was worth it for me to buy the pack and take it home.

So, the hybrid battery has been in my garage since then, just waiting for the right time for me to crack it open and pull out the cells. Theorically, this battery pack has 300 volts at 5.5AH, or about a 1.6KWH capacity. Not huge, but most hybrids use are constantly charging and discharging their battery to best overall vehicle efficiency. I figured that if I pulled out the cells and re-packed them, I could create a lower voltage pack at a higher AH capacity.

DSC_3218So, I set to work taking the pack apart. (Warning: Many battery packs are 300V+DC and potentially FATAL electric shock hazard. Kids, don’t try this at home!)

First, I removed the top cover. Pretty easy, just LOTS of bolts to take out. A power screw driver comes in handy here.

Next, I pulled out all the bolts holding on the black plastic cover over the cells. The larger bolts were very long and went all the way through the pack and into the bottom of the housing.

I was able to grab the part of the pack that held the cells and shake it a little. It was mostly loose, but still held in by connections at the service disconnect and main contractor. I also removed the cables going to the cooling fans and the physical connections of the ducts to the cooling fans. I was extra cautious working around both the service disconnect and main contractor. The cables to them are always color-coded orange, indicating high voltage wiring, typically in the neighborhood of 300V.

The cells are actually arranged in two layers, an upper and a lower. The service disconnect is between the two. So, when you disconnect the battery pack, you not only break the circuit, but also make the battery into TWO 150V battery packs, instead of one 300V pack.

DSC_3231With the service disconnect and main contractor both disconnected, I pried on the upper block of cells, and had several pieces of oak firewood handy to use as spacers to set the cells back down onto. This would give me a way to get a good grip on the block of cells and also see what other wiring might remain and need to be unplugged.

After disconnecting a few more wires, I was really to remove the upper block of cells. (Lift with the legs not the back…)
OOOOOOOOmmmmmmfmmffff! I got the cell block out and carried it over to a pair of saw-horses, where I would have better light and more room to work.

On top of the cells was an array of sensors – temperature sensors and a large circuit board for cell management, held in by about a zillion screws. I set to work removing them. I also tested the block of cells with my volt-meter and found that this half of the pack was at about 166 volts, which sounded about right for a full charge.

I removed the BMS and then trim covers on both ends of the pack. Those with the cell connections. I used the multimeter to test and saw that they were connected in a serpentine pattern so that each electrical connection was about 24 volts higher than the previous one. I removed those interconnect bolts, which finally brought the pack down from a 150V+ down to a mere pile of 6v components.

DSC_3234The cells in the pack are Sanyo NiMH “D” cells, with 5 connected in series to make 6V sticks. The entire battery pack is composed of 50 of these 6V sticks.

I checked the polarity of each with my multimeter and then marked the Negative end (-) with a black Sharpie marker. Then I pulled them out, one at a time, and stacked the sticks, all pointing the same direction.

Once I had this all figured out on the first half of the pack, I pulled out the lower layer of cells and did the same, carefully stripping out the cells.

Next, I took a look at the area on my motorcycle taken up by the lead-acid battery pack. Essentially, it was a rectangle that was 14 inches wide, 17 inches tall, and 7 inches across on the bottom. (The batteries are a different orientation on the bottom vs the top of the pack, but I’m just going with the smaller size, figuring I want the NiHM cells to be packed as a rectangle.

The NiHM cell sticks are over 13 inches long including the terminals. 14 inches is probably about right for a little space to work around them. I packed the cells into a milk crate in a 4 x 12 grid. That would mean that every two rows of four is 8 sticks (which makes 48V) and it would be 6 of those groups of 8 sticks in parallel to make the entire 48V pack for the motorcycle.

DSC_3262Next, I’ll have to figure out how to mount all the cells together. I’m thinking about laser-cutting circles in acrylic to make a clear case where all the cells would just slide through the holes to make an array. I’m not sure how much heat will be made during charge and discharge, so allowing an air-gap between the cells and adding something like a computer fan might be a good idea. I’ll probably base the spacing of the cells on reusing the bus-bar interconnects from the Escape Hybrid battery pack.

That’s it for now. I am showing off my motorcycle at an alternative-fueled vehicle day two days from now. Maybe after that, I’ll pull the lead-acid pack, to be able to take some real measurements for the NiHM cells.

Til next time, stay charged up!




Electric Motorcycle DVD Now Streaming!

by Ben N on September 22, 2014

motorcycle vimeo promo

Recently, I’ve had some requests for a STREAMING version of BUILD YOUR OWN ELECTRIC MOTORCYCLE. Frankly, there’s some parts of the world where the mail service is so bad, I simply CAN’T mail a DVD, as it just won’t get there. Also, I’m starting to find some folks who don’t have televisions or DVD players, just a laptop computer (or tablet) that won’t have a DVD drive.

So, I started looking around for what services are out there for a film-maker to release their project through. After a little searching, I decided to go with Vimeo’s On-Demand service.

So, I spent the time do a re-edit of the instructional DVD to create a “feature film” version and upload it. I originally shot all the footage in high-definition, so I’m now able to release it as an HD Film!

I really hope that folks appreciate the message and this makes it that much easier to get the word out showing how anyone can build their own electric motorcycle!

Please take a look and let us know what you think!

-Ben Nelson


This weekend, I had a chance to take a Flux Mopeds EM1 electric scooter out for an extended test ride. This is the 2014 model, which features a few upgrades from their previous version, including a higher voltage battery pack, regenerative braking, and improved motor control.

DSC_2588Overall, this is a very likable vehicle. The scooter is technically a “moped”, so keep in mind that it’s in the same class as a 50cc gasoline scooter. That means you don’t need a motorcycle license to ride it, you can park it at a bike rack, and registration is very affordable. (Keep in mind that laws on mopeds vary from one state to another, so check for your local laws.) The scooter comes with a 74V 24AH lithium battery, which is enough to take you 20-25 miles. If that isn’t enough for you, you can get an optional SECOND battery to double your range. My demo unit had both batteries, but I found that in my driving, I would have been fine with just the one.

The EM1 uses a 1500 watt brushless DC rear hub motor. While 2 HP doesn’t sound like a lot, it has a surprising amount of torque, and brought me up to 30 MPH pretty quickly. One of the great advantages of a hub motor is that there’s no chain. That means no chain NOISE and no chain maintenance or replacement.

I had several events that I had to get to this weekend – everything from running errands to attending a family reunion. The weather looked good, so I gave the scooter a workout. I did three maim trips of 14, 17.5, and 8.4 miles. On one of those, I was riding in the dark and intentionally taking a route that included a very large hill. The scooter slowed a bit on the hill, but did NOT feel overtaxed or otherwise negatively affected. The headlight offered fine night illumination.

My first trip was running errands. I went to the post office, library, and auto-parts store. At the post office, I was able to parallel park in a spot that a car wouldn’t have fit. Likewise, the library has a tight parking lot, so I instead parked right at the bike rack. When I was done at the library, it was almost hard to leave because of interest in the cycle from other library patrons. At the auto parts store, I bought 5 quarts of oil and a filter for an oil change on my truck. I simply bungeed the oil bottle to the rear cargo rack.

Other trips on the scooter were to some family events. The cycle is great in city traffic. It easily accelerates and keeps up. Acceleration is very smooth. The scooter is so quiet, I could listen to conversations of pedestrians.

Charging on the Flux is pretty slick. The scooter features a removable battery pack and an external charger. The battery pack weighs just over twenty pounds and lifts right out from under the seat. You plug the charger into the pack and into the wall outlet and then turn it on. The five amp charger will bring the pack to full capacity in less than five hours. In my usage, it never needed more than about two and a half hours to full. At maximum draw, the charger used just over 400 watts. I found this interesting because I happen to have a 400 watt PV solar panel at my house. I tracked my total energy usage for the scooter AND total energy creation from the PV for the weekend. Sure enough, I made more energy with the solar panel than I used on the scooter. I think that in this case, it would be fair to call it a “solar-powered scooter”.

The removable battery pack system allows people to wouldn’t otherwise have access to electricity in a garage or parking lot to be able to charge. For example, anyone living in an apartment or dormatory can simply bring their battery pack indoors to charge. This would be great for charging at work or anywhere else that you spend time, but don’t have access to outdoor electric outlets. If you ride in cold weather, it also means that your battery has been indoors all night and is already toasty warm, too! In short, the removable battery eliminates the need for a garage or public EV charging.

Even with two batteries in place, there’s still just enough room under the seat for the off-board charger. It was nice to have a place for it to keep the charger with me. Although I didn’t need it and didn’t use it, it was still nice to have with for peace of mind. With two batteries and the charger, I had ZERO range anxiety while using the scooter.

List price on the 2014 EM-1 is $2399. (The original version is still available as well at $1999.) For comparison, a 49CC 2013 Honda Ruckus goes for $2,649, and a 2013 Metropolitan base goes for $1999. On the other hand, by going electric you also have no gasoline cost, no oil changes, and never have to learn how to fix a carburetor. EVER.

Fuel Economy:
I tracked my miles and electric use for the weekend and found that I had traveled 39.9 miles on 2.92 Kwh of electricity. Assuming that gasoline has 33.41 KWH of energy in it, that means that I used 1/11.44th of a gallon of gas to go 39.9 miles. Thus, on a gallon of gasoline, I could have gone 456 miles. Hmmm. Not bad. I don’t know anyone driving a Prius getting 456 miles per gallon! To be completely fair, that’s still a little bit of an “apples and oranges” comparison, but it really shows how EVs are champs in the efficiency department!

Overall, it’s really hard not to like the Flux Mopeds EM1. It’s simple to run, fun to ride, and cheap to operate. It excels in the city and solves the “chicken and egg” problem of charging. Two-wheeled EVs are also great for people who still want to keep their gas car, but don’t have room or money for a full-size electric car.

Bottom Line:
The EM1 is appropriate technology for the modern world, an affordable electric that everyone will like. You owe it to yourself to go test-ride one.