is it possible to generate power to charge a 12 volt battery from a MOVING bicycle?

Question

I know....I'm probably insane, but I thought that I would give it a shot.
I know I've heard of stationary bikes that can do it...however, to me that is useless...I'd like to actually be going somewhere and generating the electricity too.... I cant seem to find this answer anywhere on the internet.

so for all of us nerds out there...is it possible to generate power to charge a 12 volt battery from a MOVING bicycle?

Answer 1

Have you ever pedaled a bike with a 3v generator? It would take 4 times the effort. I don't think it can be done.

Answer 2

Sure it could be done- why not?

We'd have to make a bracket to mount the alternator on the front tire, with the shaft rubbing up against the tire- maybe modifiy the pulley by putting some kind of rubber around it, and we need some kind of spring pressure to hold the alternator tight up against the wheel. This isn't impossible, but somewhat difficult.

We'd need some kind of battery start to set the coils on the alternator to start the field windings. Maybe one of those little 12 volt generators that rub on the tires might provide the field power for the alternator.

Since we're using an alternator with a built in regulator thats not a problem so we get 13.8 VDC out the regulator.

So, we've got 3 wires- frame ground, we ground that near the bikes frame. We've got a black ground wire out of the alternator that needs to go to a battery, along with the red wire to the battery. Lets put a 120 amp circuit breaker on the positive side for safety- don't want to blow up the frame or the battery. We could mount the battery in some kind of a harness over the rear tire. Batterys gonna need to be a Gel Cell- regular car battery will spill acid everywhere due to vibration.

Cost: Good used alternator,,,,,,,,,,,,,,,,,,,50.00
Good battery,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,50.00
Wire and connectors,,,,,,,,,,,,,,,,,,30.00
Circuit breaker,,,,,,,,,,,,,,,,,,,,,,,,,,,12.50
Stupid stuff that got missed,,,,,,,,,,,20.00

Call it 200.00 to make this happen.

Problems that will be encountered: A)This monsters gonna be a pain to steer. B) Weight is going to be around 45 pounds.

The big quesiton is- a human produces around 6/10ths of a horsepower. The smallest alternator is around 45 amps @13.8 volts DC- this comes out to about 500 watts, roughly 2/3rds horsepower- so the big quesiton is, can a person power this bike even allowing for the gear reduction of the 26" bike wheel down to a 2 or 3" gear hub? I don't know- if the battery is discharged completely this may not work. If the battery is partially discharged,,,,,I don't know.

Answer 3

Generators are available for bicycles. They generally produce a nominal 6v at about 5Watts. They are very simple and the output is AC. The voltage varies a lot with speed but you can either buy or build a regulator to charge 6v batteries.
Search for "bicycle dynamo" on the web.

With not too much thought you could build a voltage doubler to produce 12v if you really want to.

5Watts will run lights on a bicycle and charge a battery.

Answer 4

In theory, yes. You could use a generator hooked up to the wheel to generate electricity. The speed at which you could pedal would determine the voltage, and the endurance, or how long you could pedal, would determine the amperage, or amount of electricity. You would need to be a pretty avid biker, and be able to maintain a constant speed or just have a transformer built in to keep it at a steady 12 volts. I hope that I helped!

P.S. I prefer to be called a geek, because geeks get it done and nerds don't know how to. :P.

Answer 5

the bicycle is generating power! say the bicycle is not moving and is on a stand with a magnet near the wheel but does touch it and the wheel is able to move through it when you pedal. The wheel has a coils of wires around it, when you pedal you generate a current, power. If you have a capacitor you can store the energy. When coils of wire move through a magnet or vice versa it generates electricity.

Answer 6

yes, but you will have to try harder. A stationary bike doesnt have to content with things like friction, and energy lost to overcoming obstacles. Everytime you hit a bump with youre bike while moving, that is energy lost.

Answer 7

you know what i really dont know but i sure would like toknow. i wish science in school was this interesting maybe then i wouldn't be geeting e's

Answer 8

it can be done but it would not be easy to peddle while it was generating power, the more power the harder it gets

Answer 9

Yes if your speed is sufficient.
It is you who has to deliver the energy.
Th