small generators in parrellel to charge a battery

[oosnahvie]

what is the smallest fan-style generator without getting needlessly expensive that can generate a good charge?

 

[Boncuk]

Use the stepper motor of a 3 1/2" floppy disk drive. Connect a bridge rectifier to each coil and parallel the outputs.

 

[oosnahvie]

but how much power generation would that give me? in other words if i wanted a fan straight shaft to a generator no larger than 2 inches in diameter, is that around? and how much could it generate? and could i use multiple of those in parellel to charge a large battery?

 

[tcmtech]

It might light up an LED in a real strong wind!

 

[oosnahvie]

so like how much wattage in say 60 mph of wind? or how many would be required to charge 4 Kw an hour continually in 60mph winds?

 

[tcmtech]

Probably about 20 thousand.

Given even a rough estimate of 50 watts of usable energy per square foot at 60 MPH the output for a 2 inch dia blade with good aerodynamics is still only about 1.1 watts. Realistically with efficiency drops and other parasitic looses .2 watts would still be a generous value.

Why so small and what are you intending to do anyway?

 

[oosnahvie]

hybrid car idea which obviously won't work for several reasons but you know what they say... try try try again lol

 

[EN0]

Yes indeed, "Try, try, again" but in different ways. Think outside the box and inside as well.

 

[audioguru]

Many fan blades in the slipstream of an electric car will seriously ruin its streamlining so its battery must provide much more current to run the car, with hardly any power for charging. Lose, lose.

Hybrid cars use braking to generate some power to re-charge the battery. They also use a gasoline engine driving a generator to re-charge the battery.