Wind Turbine PMA for Backup Human Powered Bicycle Generator. Looking for advice on volts, cooling, manufacture, charge controller, ect.

[KITROBASKIN]

Years ago I purchased (Sportsman Guide?) an old but not used Chinese army radio battery charger that was hand pedaled. It had a folding seat to make something of a back packable load. There were many parts included in the unit and I had to configure pieces to get 12V but got to tell you, it was hard work to run a very small load. Never did feel any variable resistance in the pedaling but had to pedal pretty fast to get anything. This sounds like an interesting project though.

 

[DougfromdaUP]

How fast you pedal controls the generator voltage.
How HARD it is to pedal decides the current.
Below some pedal speed it will be really easy to turn, requiring almost no effort at all. There will be no charging current either.

Once you are going fast enough to reach the actual battery charging voltage, it will progressively become much harder to pedal, like going up an ever steepening hill, and yo will start to see an increasing charging current..
If you really lean into it and try to go even faster, the hill becomes very steep indeed, and the charging current much higher.
Torque is where the current comes from, the harder you push on those pedals, the higher the charging current.
If you back off a bit, it will become easier, but the charging current will also be less.

Exactly

 

[OzSolar]

The most elite cyclists, Tour De France, are purported to be able to maintain an average of around 250 watts. I think they need 12,000 calories a day to do that. So far. I've only been focusing my training on the calories. Up to 6,000 and once I get to ~8,000 I'll start training on the pedals.

 

[Warpspeed]

The most elite cyclists, Tour De France, are purported to be able to maintain an average of around 250 watts. I think they need 12,000 calories a day to do that. So far. I've only been focusing my training on the calories. Up to 6,000 and once I get to ~8,000 I'll start training on the pedals.

Its like running.
Anyone can run 50 yards.
Keeping it up over a 26 mile marathon is a very different thing.

An average of 250 watts over several hours is a lot, those guys are really serious.
Anyone can do 250 watts, but only for a VERY short time, a couple of minutes maybe.

Once you get into this human powered stuff, you begin to realize how truly powerful a single 250 watt solar panel is !!

 

[KITROBASKIN]

Years ago I purchased (Sportsman Guide?) an old but not used Chinese army radio battery charger that was hand pedaled. It had a folding seat to make something of a back packable load. There were many parts included in the unit and I had to configure pieces to get 12V but got to tell you, it was hard work to run a very small load. Never did feel any variable resistance in the pedaling but had to pedal pretty fast to get anything. This sounds like an interesting project though.

 

[OzSolar]

Its like running.
Anyone can run 50 yards.
Keeping it up over a 26 mile marathon is a very different thing.

An average of 250 watts over several hours is a lot, those guys are really serious.
Anyone can do 250 watts, but only for a VERY short time, a couple of minutes maybe.

Once you get into this human powered stuff, you begin to realize how truly powerful a single 250 watt solar panel is !!

I've certainly been quite humbled and left in awe by the pedal and hand crank to watt demonstrations I've been exposed too.

 

[Warpspeed]

I've certainly been quite humbled and left in awe by the pedal and hand crank to watt demonstrations I've been exposed too.

You are not alone.

 

[pollenface]

What is the difference between this and a charge controller? It seems like that is basically what it is? Just simpler?

Depends on the charge controller.

Some will buck/boost, some will brake, some will dump load. I'm just offering a cheap & simple suggestion. Take it as you wish.

 

[YahwehIsMyEl]

How fast you pedal controls the generator voltage.
How HARD it is to pedal decides the current.
Below some pedal speed it will be really easy to turn, requiring almost no effort at all. There will be no charging current either.

Once you are going fast enough to reach the actual battery charging voltage, it will progressively become much harder to pedal, like going up an ever steepening hill, and you will start to see an increasing charging current..
If you really lean into it and try to go even faster, the hill becomes very steep indeed, and the charging current much higher.
Torque is where the current comes from, the harder you push on those pedals, the higher the charging current.
If you back off a bit, it will become easier, but the charging current will also be less.

So how fit are you, how long do you want to pedal, it can be set up any way you want by altering the gearing.

It could be really easy, like going for 45 minutes while watching TV.
Or maybe a maximum effort for five minutes, where you get off that bike sweating and gasping for breath, your heart pounding and can hardly stand up.
When I was younger I could do 1/2 Hp for five minutes which is reasonable for an untrained healthy person in their prime.
That might be about 300 watts or something ? Dead easy for a couple of minutes, but that last fifth minute is a real killer.

A very serious champion cyclist should be able to hit 1Hp for several minutes.

The guy that flew the human powered Gossamer Albatross across the English Channel trained at about 1.5Hp for twenty minutes.
That is an incredible feat of strength and endurance by any standards.

So think in terms of designing for perhaps 100 watts max or less, or you will never be able to keep it up for long enough to usefully charge anything.

Alright, I think I understand. 100 watts was really what I was hoping for. I have a volt meter, but I will need to get an amp meter.

The "45 mins watching tv" is more or less what I am hoping for.

But I want to make sure I understand this correctly: Just hooking up the motor to a 12 vt battery will cause current to start to flow into the battery when the motor starts producing 12 vts, meaning that it will be pretty hard to get the motor up to even 14.5 volts or something when it is hooked up to a 12 vt battery? Is it possible to produce 20 vts? What happens to the battery if I were to get that high? Would it just basically be really hard?

Also, I would still need something in between the battery and the motor to keep it from spinning right? Would I just use diodes then? If so, what size should I need?

I also want to say, the one think having me continue to consider the AC system is the fact that I need to go quite far from where I am going to have this set up to my batteries. I understand that the rectifier would have a loss, but it seems like AC is just so much more efficient at going distances that I would regain the loss I will experience from a rectifier will be less than the loss that I would experience from having DC run the distance I need to, considering I don't have the funds to buy beefy cables for the 40 or so feet I need to have it travel.

 

[YahwehIsMyEl]

As far as something in-between the batteries and the motor, I am also just thinking about protecting my batteries.

 

[Hogheavenfarm]

Lots of responses, Good info - I am using an Fisher and Paykel washing machine motor, easy to get and AC output, although you may want to rewire the coils to meet your own needs (very easy). I do use a MW&S controller (400 amp) with a dump load which is an old Chromalox air heating element, but a stove element would do also. Because I am in a "low wind" area I use a 7 blade prop for it in the summer, and switch to a 3 blade for the winter blizzard winds. It works down to 7 mph winds. I am currently building a better housing for it as the 5 gallon bucket doesnt work very well.

 

[DougfromdaUP]

Alright, I think I understand. 100 watts was really what I was hoping for. I have a volt meter, but I will need to get an amp meter.

The "45 mins watching tv" is more or less what I am hoping for.

But I want to make sure I understand this correctly: Just hooking up the motor to a 12 vt battery will cause current to start to flow into the battery when the motor starts producing 12 vts, meaning that it will be pretty hard to get the motor up to even 14.5 volts or something when it is hooked up to a 12 vt battery? Is it possible to produce 20 vts? What happens to the battery if I were to get that high? Would it just basically be really hard?

Also, I would still need something in between the battery and the motor to keep it from spinning right? Would I just use diodes then? If so, what size should I need?

I also want to say, the one think having me continue to consider the AC system is the fact that I need to go quite far from where I am going to have this set up to my batteries. I understand that the rectifier would have a loss, but it seems like AC is just so much more efficient at going distances that I would regain the loss I will experience from a rectifier will be less than the loss that I would experience from having DC run the distance I need to, considering I don't have the funds to buy beefy cables for the 40 or so feet I need to have it travel.

All you need is a diode good for the amount of current you’ll be generating and some overcurrent protection-a fuse or breaker. That will keep your motor from draining your battery.
Yes, you will only make power when you spin your generator fast enough to get the voltage higher than the battery voltage.
Also yes, it will be very hard to get your motor up to 14.5 volts (if you have reasonable losses) because you’d have to fully charge your battery to get there. If I apply a voltage that puts 9,000 watts into my 48v battery the battery voltage goes up .01 volt every minute or so. I don’t know how big your battery is. But it will take a lot of sweat to put much power in.
As you attempt to pedal faster, the current produced by your generator wi shoot up, and the force required to turn the pedals wi shoot up. At 12 volts by the time you’re putting 100 watts into the battery it’s still only 8 amps. The cable you need isn’t that big.

 

[YahwehIsMyEl]

Lots of responses, Good info - I am using an Fisher and Paykel washing machine motor, easy to get and AC output, although you may want to rewire the coils to meet your own needs (very easy). I do use a MW&S controller (400 amp) with a dump load which is an old Chromalox air heating element, but a stove element would do also. Because I am in a "low wind" area I use a 7 blade prop for it in the summer, and switch to a 3 blade for the winter blizzard winds. It works down to 7 mph winds. I am currently building a better housing for it as the 5 gallon bucket doesnt work very well.

I have heard of this motor, though it is my understanding that you need to set up the magnets yourself? I would love a link to some sort of turorial on how to convert the motor over, as I am quite interested in it. Though I also wonder about the efficiency of such a device, do you have a chart of some sort showing the wind mph or rotor rpm / watts?

 

[Hogheavenfarm]

No need to set any magnets up. You can, but thats entirely optional if you need to build a motor to generate a specific amount of power at a certain rpm. simply re-directing (I wouldnt call it "rewiring" as its not winding coils or anything) the collection points you can make any combination you want, I have mine grouped as 4 groups of 3 coils per phase (Star pattern). These motors are available in many US and AUS washing machines, mine is from a Maytag. https://www.thebackshed.com/windmill/FPRewire.asp

 

[YahwehIsMyEl]

All you need is a diode good for the amount of current you’ll be generating and some overcurrent protection-a fuse or breaker. That will keep your motor from draining your battery.
Yes, you will only make power when you spin your generator fast enough to get the voltage higher than the battery voltage.
Also yes, it will be very hard to get your motor up to 14.5 volts (if you have reasonable losses) because you’d have to fully charge your battery to get there. If I apply a voltage that puts 9,000 watts into my 48v battery the battery voltage goes up .01 volt every minute or so. I don’t know how big your battery is. But it will take a lot of sweat to put much power in.
As you attempt to pedal faster, the current produced by your generator wi shoot up, and the force required to turn the pedals wi shoot up. At 12 volts by the time you’re putting 100 watts into the battery it’s still only 8 amps. The cable you need isn’t that big.

I see, would regular extension cord cable have a big loss to go 40 ft?

And I think I understand now. As I spin faster, and starts to produce volts higher than the battery level, it will add more resistance. So while spinning it faster would create more volts, the resistance applied from the battery is what creates the amps, and causes you not to be able to spin it faster? Is that the correct way to describe it?

 

[Hogheavenfarm]

Forgot, I do have charts (sort of) I kept while testing it. Mostly rpm vs volts at the time. There is another chart of other peoples builds as well with more detail.

 

[YahwehIsMyEl]

Forgot, I do have charts (sort of) I kept while testing it. Mostly rpm vs volts at the time. There is another chart of other peoples builds as well with more detail.

Wow this is pretty awesome!
What I don't understand about these motors is how they work. Where are the magnets? Or what is causing the electromagnet field that will create the power? Do I need to source the rotor separately?

 

[YahwehIsMyEl]

Wow this is pretty awesome!
What I don't understand about these motors is how they work. Where are the magnets? Or what is causing the electromagnet field that will create the power? Do I need to source the rotor separately?

I found the magnets... I was looking in the wrong spot. Makes sense now.

 

[Hogheavenfarm]

Here are the parts separately - only thing missing here is the aluminum cage that holds the bearings for that center shaft, I cut mine out of the drum (its embedded in it), and then burned the plastic off with a small burn barrel fire which worked nicely. The old bearings were shot so I put in new ones and made some brackets to hold it in place.

 

[YahwehIsMyEl]

Here are the parts separately - only thing missing here is the aluminum cage that holds the bearings for that center shaft, I cut mine out of the drum (its embedded in it), and then burned the plastic off with a small burn barrel fire which worked nicely. The old bearings were shot so I put in new ones and made some brackets to hold it in place.

Wow this is awesome! Thanks for the info! I am now considering this option more than I was.