Difficult question need Help!!!! please
So I just purchased this electric moped http://www.powersportsmax.com/produc...ducts_id/14516. i want to create a recharging system while riding utilizing a fan or "turbine" connected to a dc motor seeing as in how 25 mph will be generatiing quite a bit of wind. I need to know which motor would be sufficient to offset the power usage of the moped while riding? I know it's a high aimed goal but i think it would be possible? Any help would be much appreciated. Also, another Idea I had was running the dc generator by putting something like a wooden dowel on the tire causing it to spin or along the belt to the rear wheel, spiining the motor like the wheel would. Would an of these ideas work? Cn someone provide some knowledge on these ideas? Thank you.
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It doesn't work that way -- the additional load you put on the existing motor would be more than any energy created.
What you're trying to create is basically a perpetual motion machine -- and it just doesn't work. The only time what you're talking about makes sense is when you're intending to slow down already, and many electric bikes already have a feature that recovers some of that energy -- it's called regenerative braking. It's also found in hybrid cars (and really, it's the #1 reason for making them hybrid in the first place.) In any event, if you're after regenerative braking, you don't want to use fans or turbines -- you want to use a generator coupled to a wheel. And since electric bikes already have one -- the main motor -- they just use that. (Motors and generators are basically the same thing.) |
Originally Posted by dougmc
(Post 14690929)
It doesn't work that way -- the additional load you put on the existing motor would be more than any energy created.
What you're trying to create is basically a perpetual motion machine -- and it just doesn't work. The only time what you're talking about makes sense is when you're intending to slow down already, and many electric bikes already have a feature that recovers some of that energy -- it's called regenerative braking. It's also found in hybrid cars (and really, it's the #1 reason for making them hybrid in the first place.) In any event, if you're after regenerative braking, you don't want to use fans or turbines -- you want to use a generator coupled to a wheel. And since electric bikes already have one -- the main motor -- they just use that. (Motors and generators are basically the same thing.) |
What I am essentially wondering is, if I supply the battery will more power that it takes to operate? Will it charge? If not, which seems to be the case, why?
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Originally Posted by James123456
(Post 14691074)
What I am essentially wondering is, if I supply the battery will more power that it takes to operate? Will it charge?
But if this current is coming from a windmill that is being powered by the bike itself, which is powered by a motor powered by the battery ... your windmill will slow the bike, which will put more load on the battery than it will add to the battery. The laws of physics are not on your side here. Now, if the windmill is charging the bike while it's parked due to it being a windy day, that's another matter -- but if the wind comes from the motor moving the bike, no, that's not going to work. Look at it this way ... if this worked, why don't cars have air turbines on top? If we could make an electric car that charged itself while it was driving so it only needed a small battery to go hundreds of miles, we would, and everybody would be driving one because they'd never need gas or charging. But the laws of physics don't work that way. |
Understandable. My previous part was meant in complete disregard top the windmill idea. If i were to just have the dc motor being spun off of thebelt or tire. Could i apply more power to the battery? Could multiple motors offset the initial load plus the additional load needed to spin the motors?
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I get this all the time between the electric car and the electric bike. I
am surprised at some of the people that ask it, people who I would think would really know better. Repeat this until you understand. There are losses in ANY system, it may be friction, resistance in wiring, wind resistance or any other number of things. You ALWAYS get less out than you put in. |
Originally Posted by Metal Man
(Post 14691514)
I get this all the time between the electric car and the electric bike. I
am surprised at some of the people that ask it, people who I would think would really know better. Repeat this until you understand. There are losses in ANY system, it may be friction, resistance in wiring, wind resistance or any other number of things. You ALWAYS get less out than you put in. |
Originally Posted by James123456
(Post 14691589)
well how far could i extend my range? If i were to add motors sucj as the one s in my previous post?
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Originally Posted by dougmc
(Post 14691647)
You would reduce your range.
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I am accepting the no turbine idea. But if a motor like the one i posted a link for was added along the drive belt and operated at the full 750 watts...still nothing? I would think that that amount of power would offset the drag or resistence and produce a usable amount of electricity. It would be direct belt to motor. No turbine at all. Can i get an equatios maybe to figure some of this out instead of asking generally the same question?
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If you run your added motor as a generator it will require power from the first motor to generate electricity. If you run it as a motor you will be powering two motors.
Let me answer your question with a couple of questions to help you understand this. How much power do you think it takes to run a generator? Where does this power come from? |
In other words, what everyone is trying to say, the ONLY way you will get any additional power is to run a second motor as a regenerative powering motor to slow you down.
If the scooter already has regenerative braking, then that's your best bet. |
Originally Posted by SpecialX
(Post 14692091)
If the scooter already has regenerative braking, then that's your best bet.
They probably won't produce enough power while moving to power the thing by itself (unless they're huge) but they'll charge things a little -- even when parked. |
Im not grasping the whole regenerative breaking adding another motpr concept.. as for the questions. I dont know. That is what i am tryong to figure out. I need to know how much power will be used to operate the 750 or larger watt motor i posted the link to at full power. If someone can give m e an answer, preferably numerical, to that i can see how it will draw the current in comparison the initial500 watt load. Sorry to,keep annoying those of you who see this as simple, i just dont without numerical proof...
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How much power will a 750 watt motor take at full power? 750 watts would seem to be the answer, though in reality such a motor can probably handle a lot more than that for a short period. (The power ratings are usually largely about cooling.) Though I really don't understand what you're asking.
But as for recharging your battery to extend your range ... you want numbers? Suppose your electric bike will use 250 watts to propel you at 20 mph on level ground. You then add a generator that is powered by the wheels (or a turbine powered by the air, whatever) and this generates 40 watts of power that you add back to the battery. However, you now find that your bike needs 350 watts to go at 20 mph on level ground. So you've spent 100 extra watts to generate 40 watts, reducing your range. As for what regenerative braking (not breaking) is, consider that it's off most of the time. But if you want to slow down, rather than hit your usual brakes, you hit the regenerative brake, which slows the bike down -- by using a generator to charge the battery. So you recover some of the energy as you slow down, and that does extend your range. And since motors and generators are the same thing, in general you don't even have a separate generator at all -- it's done with the same motor you use to power the bike in the first place. |
That was the original answer I was seeking. Sorry about the typo on breaking/braking, I was using my phone.
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The reason I asked about the motor is becaused it wouldn't be using the scooters power source (directly), it would be creating power using the drive belt to spin the motor thus using it as a generator. The amount of resistance needed to spin the motor would be the only resistance (beside the slight bit of weight added). That's why this is not clicking. My question about how much power was more aimed toward how fast would that motor need to spin in order to create it's peak power? ( Spinning from the drive belt)
In referece to your recent example: If the electric bike will use the initial 250 watts to propel me at 20 mph I would need less than 250ohms of resistance ( to allow the motor to put out above 500 watts) to add more charge to the battery correct? And that is not possible...correct? |
And if my scooter doesnt have regenerative braking, could I add a dc motor like my idea that would be engaged while wanting to slow down?
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Originally Posted by James123456
(Post 14693928)
My question about how much power was more aimed toward how fast would that motor need to spin in order to create it's peak power? ( Spinning from the drive belt)
In referece to your recent example: If the electric bike will use the initial 250 watts to propel me at 20 mph I would need less than 250ohms of resistance ( to allow the motor to put out above 500 watts) to add more charge to the battery correct? And that is not possible...correct? And if my scooter doesnt have regenerative braking, could I add a dc motor like my idea that would be engaged while wanting to slow down |
a motor and a dynamo are both a few coils of wire rotating around a permanent magnet.
1 goes when the power is applied, the regeneration is having it make a little juice when its off , and in coast down.. won't be 1:1 of course.. |
New question. How could I increase my top speed? And if I were to wire a battery in parrallel to extend my range what battery would work well?
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Originally Posted by James123456
(Post 14718165)
New question. How could I increase my top speed?
And if I were to wire a battery in parrallel to extend my range what battery would work well? |
Ok just brainstorming. Would jt have to be in series to keep the same voltage?
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If you have to ask your last question, you should probably start googling battery technology first..
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