There’s a bunch of different electric scooters available nowadays, including those hoverboards that keep catching fire. [TK] had an older Razor E300 that uses lead acid batteries. After getting tired of the low speeds and 12 hour charge times, [TK] decided it was time to swap for lithium batteries.
The new batteries were sourced from a Ryobi drill. Each provides 18 V, giving 36 V in series. The original batteries only ran at 24 V, which caused some issues with the motor controller. It refused to start up with the higher voltage. The solution: disable the safety shutdown relay on the motor controller by bridging it with a wire.
With the voltage issue sorted out, it was time for the current limit to be modified. This motor controller uses a TI TL494 to generate the PWM waveforms that drive a MOSFET to provide variable power to the motor. Cutting the trace to the TL494’s current sense pin removed the current limit all together.
We’re not saying it’s advisable to disable all current and voltage limits on your scooter, but it seems to be working out for [TK]. The $200 scooter now does 28 km/h, up from 22 km/h and charges much faster. With gearing mods, he’s hoping to eke out some more performance.
After the break, the full conversion video.
Continue reading “Converting an Electric Scooter to Lithium Batteries and Disabling the Safeties”
Do you have a spare mobility scooter sitting unused in your garage? Or, maybe you’ve got a grandmother who has been complaining about how long it takes her to get to bingo on Tuesdays? Has your local supermarket hired you to improve grocery shopping efficiency between 10am and 2pm? If you answered “yes” to any of those questions, then the guys over at Photon Induction have an “overclocked” mobility scooter build which should provide you with both inspiration and laughs.
They’ve taken the kind of inexpensive mobility scooter that can be found on Craigslist for a couple hundred dollars, and increased the battery output voltage to simultaneously improve performance and reduce safety. Their particular scooter normally runs on 24V, and all they had to do to drastically increase the driving speed was move that up to 60V (72V ended up burning up the motors).
Other than increasing the battery output voltage, only a couple of other small hacks were necessary to finish the build. Normally, the scooter uses a clutch to provide a gentle start. However, the clutch wasn’t up to the task of handling 60V, so the ignition switch was modified to fully engage the clutch before power is applied. The horn button was then used as the accelerator, which simply engages a solenoid with massive contacts that can handle 60V. The result is a scooter that is bound to terrify your grandmother, but which will get her to bingo in record time.
Continue reading “Making a Mobility Scooter Drastically More Mobile”
We’re all familiar with hybrid gas-electric cars these days, but how about a hybrid scooter that uses supercapacitors instead of batteries? Our hats are off to [Alex] from Labs Bell for the almost entirely-DIY conversion.
The hybrid idea is to drive the vehicle’s wheels with electric motors, but generate the electricity with a normal gasoline engine. This allows the hybrid to control the engine speed almost independently of the wheel motors’ demand for power, allowing the gas engine to run at its most efficient speed and charge up batteries with the extra energy. As an extra bonus, many hybrids also use regenerative braking to recoup some of the energy normally wasted as heat in your brake pads.
[Alex]’s hybrid scooter does all of the above and more. Since the stock vehicle is a 50cc scooter, any increase in acceleration is doubtless welcome. We’d love to see the scooter starting from stop with a full charge. Using supercapacitors as storage instead of batteries is a win for charging efficiency. In urban stop-and-go traffic, the natural habitat of the 50cc scooter, the regenerative braking should help further with gas consumption.
What’s most impressive to us is the completely DIY hybrid control unit that takes some simple inputs (wheel speed and throttle position) and controls regenerative braking, the gas engine’s throttle, etc. Since the hybrid control system is currently under development, there’s even a button to switch between different trial algorithms on the fly. Very cool!
Oh yeah, and [Alex] points out the fire extinguisher on-board. He had occasion to use it for his hybrid motorcycle V1. Safety first!
Please don’t judge [Alan] on his choice of vests. This project is from 1999 when it was common to see people rockin’ these threads. Anyone who has ever spent time on the University of Minnesota campus in Minneapolis, Minnesota will know that parking is at a premium. [Alan] had a 12-15 minute walk from his parking garage to his office and was considering a cheaper parking location that would balloon that to 20-25 minutes. But engineers don’t see problems, they see project ideas. He started work on a tiny electric scooter that could slim down his commute. Obviously he did find some success, but it was interspersed with failures that make his scooter the Fail of the Week.
Continue reading “Fail of the Week: Commute-Shortening Electric Scooter”
We’ve seen a fair share of carputer builds involving a Raspberry Pi in the last few months, but even the power of a Raspi can’t compete with the awesomeness of this Arduino-powered scooterputer.
Like all awesome projects, this build is the product of a massive case of feature creep. Initially, [Kurt] only wanted a voltage monitor for his battery. With an Arduino Duemilanove, a voltage divider, and an evening of coding, [Kurt] whipped up a simple device with three LEDs to indicate the status of the batter: either low, good, or charging.
The project was complete until he ran across an awesome OLED screen. Using a touch screen display for just battery monitoring is a bit overkill, so [Kurt] made a trip over to Sparkfun and got his hands on a temperature sensor, real-time clock, accelerometer, GPS sensor, and even a cellular shield.
The resulting scooterputer is a masterpiece of in-vehicle displays: there’s a digital speedometer and GPS unit, and the cellular shield works as a tracking device and a way to download real-time maps of the scooter’s current location with itouchmap.
While the majority of the electronics are hidden under the hood of the scooter, the display of course needed to be out in the weather. To do this, [Kurt] found a nice enclosure with a rubber boot that perfectly fit the OLED display. The display is connected to the Arduino with a cat5 cable, and everything should hold up pretty well as long as [Kurt] doesn’t drive through a hurricane.
You can check out a video of the scooterputuer below.
Continue reading “Scooterputer, the all-in-one scooter computer”
Travel backpacks are so passé. All the cool kids, like [Niklas Roy] are using scooter trunks for easy travel. Think of it, not only does it remove the need to carry your heavy baggage, but you get to coast along for the ride as well. We wonder what the officials at air, train, and bus travel hubs are going to think?
The idea came from seeing a similar build with a flight case (plywood box with metal edges and hardware). In that project the flight case folded out to be something of an impromptu street kiosk. But [Niklas] knew the aluminum camera trunk he uses for travel was going to work great in the project. He designed a bracket to replace the steering column on his kick scooter. It holds the case securely in place, but still allows the scooter to fold down to be stowed in the train overhead bin.
At first we thought this would have been better if integrated into the trunk itself. Keeping the two parts separate means you can leave the case wherever you’re staying and take just the scooter for day trips.
This all-terrain electric scooter can destroy the speed limit in a school zone without even trying. [Ben Katz] built from the ground-up and did an amazing job of documenting the journey.
He strated by redesigning the suspension of a plain old kick-scooter to use these large inflatable wheels. This includes a suspension system that helps cushion the rider from the bumps of an uneven driving surface. The increased deck height leaves plenty of room for the locomotive parts. You can see the three cylinders mounted near the rear wheel. Those are the motors, connected to a single drive shaft with a gear box which [Ben] built. The drive shaft powers the rear wheel via chain drive. Batteries are housed in the rectangular enclosure in front of the motors.
Don’t miss the video after the break. [Ben] takes the thing on and off-road, averaging 15 MPH while topping out at 24!
Continue reading “All-terrain electric scooter build”