best electric bicycle for hills image
Q. The only thing I've heard is that they even out hills a little. What else have you heard? Are they worth the high price?
Answer
You can buy a nice shop quality bike for the same price as a cheap electric bike. You will benefit from the exercise and be a lot healthier. Don't expect the batteries to last long on the cheap bikes so you end up with a 70 lb bicycle or ending up pedaling harder then a regular bike. Expect to buy a new battery pack every 6 months or so.
You can buy a nice shop quality bike for the same price as a cheap electric bike. You will benefit from the exercise and be a lot healthier. Don't expect the batteries to last long on the cheap bikes so you end up with a 70 lb bicycle or ending up pedaling harder then a regular bike. Expect to buy a new battery pack every 6 months or so.
How much energy loss would be if I used generator and motor to propel a bicycle instead of pedaling directly?
cdr
I'm thinking of making a lightweight scooter that can be propelled by electric motor, but can be pedaled if the battery is gone. Instead of making the pedaling component main function, i want to pedal to store/generate electricity. Does this physically/electronically make sense, or would there be too much energy loss? What if I can find very efficient motor and generator?
Answer
About the best efficiency you can get with electric machines (motors/generators) is 90%, and this might be tough to find. Smaller motors are more likely to be about 80%. If you do get 90% on both, you can multiply 0.9*0.9=0.81 or about 80% total efficiency (ignoring friction loss etc. which you would have some of anyways). If your willing to pedal about 20% harder than a direct connection ... your good to go.
I have a couple of pretty big (about the size of car starter) 50V DC motors. When I hook them together and turn the shaft of one with my hand, the other turns almost as fast. They are pretty efficient ... so I think you have a chance.
Consider charging the battery with the motor as well. You could recover some of the power with regenerative breaking or when going down hill etc. and reuse it.
I'd do some efficiency tests with the generator/motor before you decide to build this thing ...
About the best efficiency you can get with electric machines (motors/generators) is 90%, and this might be tough to find. Smaller motors are more likely to be about 80%. If you do get 90% on both, you can multiply 0.9*0.9=0.81 or about 80% total efficiency (ignoring friction loss etc. which you would have some of anyways). If your willing to pedal about 20% harder than a direct connection ... your good to go.
I have a couple of pretty big (about the size of car starter) 50V DC motors. When I hook them together and turn the shaft of one with my hand, the other turns almost as fast. They are pretty efficient ... so I think you have a chance.
Consider charging the battery with the motor as well. You could recover some of the power with regenerative breaking or when going down hill etc. and reuse it.
I'd do some efficiency tests with the generator/motor before you decide to build this thing ...
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Title Post: What is riding one of the electric power assist bicycles like?
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Rating: 83% based on 9498 ratings. 4 user reviews.
Author: Unknown
Thanks For Coming T0 My Blog
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