Siamese Electric Motors


I’ve been meaning to post something about these for a while. Jim builds motors for EV hobbiests on the side – one of his cooler creations is the siamese electric motor. Some others have used belt drives to combine motors, but Jim actually builds the motors into a single unit. He built this set of 8 inch twins for the White Zombie drag racer.

I pumped Jim for more details, but he’s not done tweaking his next set of siamese motors. So, why is this even a hack? It’s a nice piece of machine work, but it gets interesting if you consider some stock specs. Most EV cars get 9″ motors – these are rated at 19hp or so. They take some monster hardware just to drive – high amperage, high voltage. Running a pair of 8hp motors can produce similar power with significant cost savings – everything gets cheaper. To generalize, you need a $1500 motor and $1000 controller just to get in the game. Not to mention that rebuildable forklift motors can be had for a song.

Electric 7 EV


Yup, more EV stuff today. This car [Cache mirror]is just so impressive that I think it’s definitely worthy. The car is a Birkin S-3 reproduction kit. Instead of the 4 cylinder, he put in a 3 phase 100HP, yes, 100HP electric motor. That’s pretty kickin. The *really* interesting twist is the battery pack. Multiple hybrid car battery cells (think prius NiMH) were salvaged to provide the juice. It runs around on tires designed for the EV1.

Sequential Battery Charging


I’m getting pretty interested in building an electric motorcycle, and I ran across this little hack to charge multiple batteries with one charger. It uses a 4020 counter that’s pulsed by my dear friend the 555 to activate a series of relay pairs to switch a single charger sequentially between battery cells. A more advanced version could use a microcontroller to monitor the state of each cell to ensure even charging. If you’re thinking of constructing an uber-ups, this could be useful.

Electric Motorcycle


Lets face it, riding a segway or any other electric scooter just doesn’t get quite the respect that we’d wish. Eliot pointed out this video of an excellent electric motorcycle conversion in action. It’s a such a clean looking conversion that I couldn’t resist posting it. The major components to do the conversion were six SLA batteries with a DC converter that acts as a speed controller. I think it sounds like a giant R/C car rolling down the road.

I’ve been meaning to build an electric bike myself. I think there’s a huge potiention for EV home builders and bikes. The component cost is significantly less for a bike, and it’s just ideal for one-off development. Perhaps the day of the dorky EV is ending? [via kneeslider]

[Update: Calling this a motorcycle is a bit generous. Since it’s a 50cc chassis originally, it’s technically a converted moped. Still, I wanna see Woz charge one of these with his segway…]

Improved VW Solar Charger

Batwatch

VW has been shipping their cars to the US with small solar panels inside to keep the batteries from going dead during shipment. Dick Streefland picked one up and added a small monitor circuit to monitor and charge his battery. Batwatch is based on the Atmel ATtiny13V and measures the voltage on two sides of a resister to determine the voltage of the battery while the solar panel is charging the system.

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