I want some advice on motorizing my bike.

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SUMMARY

This discussion focuses on motorizing a bicycle using a DC motor and explores various power sources. A configuration of four car batteries in series for 48 volts is suggested, requiring approximately 20 amps for a 1 HP motor. Alternatives to heavy car batteries include using two 24-volt batteries or considering a gas motor for better power-to-weight ratio. Additionally, the idea of using an AC generator powered by pedaling to assist the motor is proposed, allowing for energy recovery during downhill rides.

PREREQUISITES
  • Understanding of DC motor specifications, particularly 48V configurations.
  • Knowledge of electrical power calculations, specifically P=IV.
  • Familiarity with battery types and their weight implications for electric vehicles.
  • Basic concepts of energy conversion, including mechanical to electrical energy.
NEXT STEPS
  • Research 48V DC motor options and their specifications for bicycle applications.
  • Explore lightweight battery alternatives for electric bicycles, such as lithium-ion batteries.
  • Learn about throttle control mechanisms used in electric vehicles.
  • Investigate AC generators and their integration with DC motors for hybrid energy solutions.
USEFUL FOR

DIY enthusiasts, electric bicycle builders, and individuals interested in alternative energy solutions for personal transportation.

math_way
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Hi!

I thought of motorizing my 2 wheeler.
1) Now i want to know how much Voltage (DC motor) is required to turn my wheel.
2) The source of energy? (Maybe Electric). If electric, I know it will be difficult to use batteries to run the motor. Considering car batteries, they are just too heavy. Any suggestions?
3) Throttle. I need some help on that as well, as in synchornizing the wheel movement with the throttle.

Thank You.

Regards,
math_way
 
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I'm assuming you want to go more than 10 feet?

If so...4 car batteries hooked in series for 48 volts outta do the trick.

I'm guessing 1 HP outta do...that's about 746 watts for a 48 volt dc motor.

P=IV

746=I*48

Current will be 15.54...so figure 20 amps with magnetic field losses and so forth...#10 wires outta do the trick to the motor.

For throttle...use the same thing they use on the tyco trains...that little slide device that controls the speed of the train.

Have a nice day.
 
But each car battery weighs roughly 20 lbs... and 4 such batteries will weigh about 80 lbs. That's a little too much weight... any alternative?
 
I have been looking into this too and I found this on eBay for pretty cheap, I think , lol

It's a kit, they have others if you look

http://www.ebay.com/itm/48V1000W26-Front-Wheel-Electric-Bicycle-Motor-Kit-E-Bike-Cycling-Hub-Conversion-/390406828047?pt=LH_DefaultDomain_0&hash=item5ae60f700f
 
math_way said:
But each car battery weighs roughly 20 lbs... and 4 such batteries will weigh about 80 lbs. That's a little too much weight... any alternative?

Sure...two 24 volt batteries in series for 48 volts. Your motor scooter will now go half the distance as the 4 batteries.

Electric powered vehicles are difficult to make...and as you can see the power to weight ratio is not very good. There are some electric cars now...but they aren't exactly lighting the world on fire. Not yet anyway.

Try a gas motor. The power to weight ratio is amazing.
 
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Here's possibly a better idea that would be more fun.

Power an DC motor with an AC generator into a full wave rectifier. The AC generator would be powered by your legs.

If you could get 1 HP out of your legs...this would translate into less than 1 HP to your motor due to heat and magnetic field losses...but still would be kinda nifty since you are just looking to play around.

Maybe you could add a small battery as well that could assist or get charged by your generator as well. Then figure out a way to charge your battery when you were going down hills and so forth...just like the hybrids.
 
psparky said:
Here's possibly a better idea that would be more fun.

Power an DC motor with an AC generator into a full wave rectifier. The AC generator would be powered by your legs.

If you could get 1 HP out of your legs...this would translate into less than 1 HP to your motor due to heat and magnetic field losses...but still would be kinda nifty since you are just looking to play around.

Maybe you could add a small battery as well that could assist or get charged by your generator as well. Then figure out a way to charge your battery when you were going down hills and so forth...just like the hybrids.

Nice Idea! I too thought of converting Mechanical Energy to Electrical Energy, therby powering my motor bike with the electrical energy. Sounds great! I'll see what I can do. And I'll update you on my progress. Thank You!
 

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