Supercapacitor E-Bike With DIY Motor

October 3, 2021 by Danie Conradie 26 Comments

Supercapacitor technology often looks like a revolutionary energy storage technology on the surface, but the actual performance numbers can be rather uninspiring. However, for rapid and repeated charge and discharge cycles, supercaps are hard to beat. [Tom Stanton] wanted to see if supercaps have any practical use on e-bikes, and built a DIY electric motor in the process.

One of the problems with supercaps is the rapid voltage drop during discharge compared to batteries, which can limit the amount of usable energy. In an attempt to get around the voltage limitation, [Tom] built his own axial flux motor for the bike, using 3D printed formers for the coils and an aluminum rotor with embedded magnets. He expected torque to be severely limited, so he also machined a large sprocket for the rear wheel. He built a capacitor bank using six 2.7V 400F supercaps, only equivalent to the capacity of a single AA cell. Although it worked, the total range was only around 100 m at low speed. When he hooked the motor up to a conventional battery, he did find that it was quite usable, if a bit underpowered.

The controller for the DIY motor was not capable of doing regenerative braking, so he fitted the capacitors to another e-bike that does have regenerative braking. Using this feature, he was able to reclaim some power while slowing down or going downhill. Since this type of charging cycling is what supercaps are suited for, it worked, but not nearly to the level of being practical.

[Tom]’s projects are a popular feature here on Hackaday, and he has also experimented with supercaps in RC “rockets” and a flywheel for energy storage on the same bike.

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EBike Conversion On A Budget Uses Skateboard Motor

August 28, 2021 by Mike Szczys 30 Comments

[Dave Schneider] has been chasing an electric-bike build for more than 10 years now. When he first started looking into it back in 2009, the cost was prohibitive. But think of how far we’ve come with the availability of motors, electronic speed controllers, and of course battery technology. When revisiting the project this year, he was able to convert a traditional bicycle to electric-drive for around $200.

Outrunner motor drives rear wheel via friction

Electric skateboards paved the way for this hack, as it was an outrunner motor that he chose to use as a friction drive for the rear wheel. The mounting brackets he fabricated clamp onto the chain stay tubes and press the body of the motor against the tire.

The speed of the motor is controlled by a rocker switch on the handlebars, but it’s the sensors in the brake levers that are the neat part. Magnets added to each brake lever are monitored by hall-effect sensors so that the throttle cuts whenever it senses the rider squeezing the front brake (effectively free-wheeling the bike), while the rear brake triggers a regenerative braking function he’s built into the system!

Sure you can buy these bikes, you can even buy conversion kits, but it’s pretty hard to beat the $88 [Dave] spent on the motor when the cost of purpose-built motors is usually several times this figure. The rest is fairly straight-forward, and besides ordering batteries and an electronic speed controller, you likely have the bits you need just waiting for you in your parts bin.

Electric Wheelbarrow Makes Hauling Big Loads Easier

September 19, 2018 by Richard Baguley 20 Comments

Gardening involves a depressing amount of physical activity: haul this over here, dump it there and then cover it with this. Things like wheelbarrows are still damn hard work, especially for people like who are somewhat physically compromised. That’s why we love this build from [Karl Gesslein]. He usually makes electronic bikes, adding motors to bicycles to roam the streets faster. But this time he applied his expertise to a wheelbarrow. He added a 3000W motor to the wheelbarrow, which drives the front wheel when triggered by the accelerator on the handle.

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Regenerative Braking Charges Your Phone

August 8, 2018 by Lewin Day 17 Comments

Way back when, if you wanted lights on your bike, you’d head off to the local bicycle store and purchase yourself a bottle dynamo. This would consist of a magneto that was attached to a bracket on the back of the bike and would rotate by rubbing against the rear tire, generating power for the lights. These fell out of favor over the years as batteries got better and cheaper and people grew tired of the increased drag and maintenance required. Despite this, the idea of generating power onboard a bicycle has never really gone away, and [Javier] has decided to have a crack with his imPulse project.

The formerly popular bottle dynamo had one advantage over contemporary models located in bicycle hubs – they were geared down to allow the generating device to make multiple turns for each revolution of the bicycle wheel. This is useful to allow the generating device to operate in its ideal range of rotational speed. Going for a more modern take, however, [Javier] has decided to leverage a stepper motor as his generating device of choice. Further taking advantage of modern technology, the imPulse system is designed to fit on to the caliper mounts of modern bicycles with disc brakes, allowing easy fitment while also leaving room for a geared-down drive.

[Javier] hasn’t just stopped at power generation, however – there are also plans for lighting systems and power distribution to enable the generated power to be used for a variety of purposes. It even has turn signals – though that’s not the first time we’ve seen them on a bike! Video after the break.

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An E-Bike Battery Pack Without Spot Welding

July 3, 2018 by Dan Maloney 44 Comments

In somewhat of a departure from their normal fare of heavy metal mods, [Make It Extreme] is working on a battery pack for an e-bike that has some interesting design features.

The guts of the pack are pretty much what you’d expect – recovered 18650 lithium-ion cells. They don’t go into details, but we assume the 52 cells were tested and any duds rejected. The arrangement is 13S4P, and the cells are held in place with laser-cut acrylic frames. Rather than spot weld the terminals, [Make It Extreme] used a series of strategically positioned slots to make contacts from folded bits of nickel strip. Solid contact is maintained by cap screws passing between the upper and lower contact frames. A forest of wires connects each cell to one of four BMS boards, and the whole thing is wrapped in a snappy acrylic frame. The build and a simple test are in the video below.

While we like the simplicity of a weld-less design, we wonder how the pack will stand up to vibration with just friction holding the cells in contact. Given their previous electric transportation builds, like this off-road hoverbike, we expect the pack will be put to the test soon, and in extreme fashion.

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[GreatScott] Tests His DIY Battery Pack On His E-Bike

May 28, 2018 by Steven Dufresne 19 Comments

[GreatScott] has now joined the ranks of Electric Bike users. Or has he? We previously covered how he made his own lithium-ion battery pack to see if doing so would be cheaper than buying a commercially made one. But while it powered his E-bike conversion kit on his benchtop, turning the motor while the wheel was mounted in a vice, that’s no substitution for a real-world test with him on a bike on the road.

Since then he’s designed and 3D printed an enclosure for his DIY battery pack and mounted it on his bike along with most of the rest of his E-bike kit. He couldn’t use the kit’s brake levers since his existing brake levers and gear-shift system share an enclosure. There also weren’t enough instructions in the kit for him to mount the pedal assistance system. But he had enough to do some road testing.

Based on a GPS tracker app on his phone, his top speed was 43 km/h (27 miles per hour). His DIY 5 Ah battery pack was half full after 5 km (3.1 miles) and he was able to ride 11.75 km (7.3 miles) on a single charge. So, success! The battery pack did the job and if he needs to go further then he can build a bigger pack with some idea of how it would improve his travel distance.

Sadly though, he had to remove it all from his bike since he lives in Germany and European rules state that for it to be considered an electric bike, it must be pedal assisted and the speed must the be progressively reduced as it reaches a cut-off speed of 25 km/h (15 miles per hour). In other words, his E-bike was more like a moped or small motorcycle. But it did offer him some good opportunities for hacking, and that’s often enough. Check out his final assembly and testing in the video below.

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Hoverboard Reborn For Electric Rollerblading

October 31, 2017 by Dan Maloney 8 Comments

Rollerblading is fun, but who needs all that pesky exercise? Wouldn’t strapping on the blades be so much more tempting if you had an electric pusher motor to propel you along your way?

We have to admit that we raised a wary eyebrow as we first watched [MakerMan]’s video below. We thought it was going to be just another hoverboard hack at first, but as we watched, there were some pretty impressive fabrication skills on display. Yes, the project does start with tearing into a defunct hoverboard for parts, primarily one wheel motor and the battery pack. But after that, [MakerMan] took off on a metalworking tear. Parts of the hoverboard chassis were attached to a frame built from solid bar stock — we’ll admit never having seen curves fabricated in quite that way before. The dead 18650 in the battery pack was identified and replaced, and a controller from an e-bike was wired up. Fitted with a thumb throttle and with a bit of padding on the crossbar, it’s almost a ride-upon but not quite. It seems to move along at quite a clip, even making allowances for the time-compression on the video.