charge controller for wind turbine

[sandyshore]

we are making a wind turbine and need to buy a charge controller that stops the batteries from overcharging with a dump load facility

all the ones we can find are related to bought wind turbines and they cant be used on home made turbines

can anyone help?

[KathyLauren]

they cant be used on home made turbines

That sounds like nonsense. A charge controlled knows volts, amps and watts. That's all it needs to know.

If you ask a salesman what controller is suitable for your turbine, he's going to give you that answer because he doesn't want to be held liable if you fry something. So, you have to do your own homework and know ahead of time the volts, amps and watts and which controllers can handle them. Then, if the salesman asks you what it's for, don't answer. Just tell him that's the model you want.

[sandyshore]

thank you

however all the ones that we can find slow down the wind turbine and then stop it once the batteries are fully charged

this will be impossible with our home made turbine

[Odsox]

No, not so.
Any charge controller will work with any form of generation whether it's a home made wind turbine, commercial turbine, hydro turbine, solar PV panel, conventional battery charger or even a petrol/diesel generator.
All the charge controller does is monitor the battery voltage and when it determines that the batteries are fully charged it switches the incoming power to another pair of contacts.
What you connect to those other contacts is up to you, it can be a resistor dump load or a low voltage immersion heater or an inverter permanently connected to a suitable load like a heater.
All you have to do is make sure that the dump load you choose is matched to the maximum power coming from the wind turbine when it's really windy. So if you have a 12v turbine that can generate a maximum of 240 watts you need to dump 20 amps.

You say that it's impossible to slow your turbine, why is that ?
You have to have some way of slowing your turbine otherwise it will destroy itself in very high winds (which would be extremely dangerous) and it needs to be an automatic process for those times when an unforecasted gale springs up in the middle of the night. Either you need to furl in some way or put a big load on to electrically slow it down.

My turbine supplies our house lights through an inverter when the batteries are reasonably charged, but if the batteries are fully charged it switches over to supply our house sockets as well. But if that is not enough it's last course of action is to switch the DC line to a dump load of 2 ohms suspended in a paint can full of oil.

Hope some of that helps.

[dave45]

Any charge controller will work with any form of generation whether it's a home made wind turbine, commercial turbine, hydro turbine, solar PV panel

Not strictly true either. My BP Solar charge controller controls the solar PV panels by shorting them out. It does it with fancy algorithms (that they don't explain) via pulse width modulation. When it starts to control it will short out say 10% of the time, and as the battery voltage rises it shorts out 90% 91% --- all the way to 100%.

Now shorting out a PV panel does no damage.

Shorting out a WT is effectively putting the brakes on.

Shorting out a WT in pulses creates one hell of a bad scenario - intermittent braking causes huge amounts of vibration and noise (and must cause humungous amounts of inductive voltage spikes) ... I know I tried it on mine ... for a few seconds.

So PWM controllers are no good for WTs. The dump-load controllers are fine, but can waste a lot of energy if your dump load doesn't do anything useful.

PS - Just checked Marlec's website and their new controller seems to do just what I said not to do


so now I am confused ......