Charge control @minimum cost.

Thread Starter

ouzcoskun

Joined May 12, 2016
32
Hello,
I just build 2 wind propellers and made 2 dynamos out of trash.
My first dynamo is made of an old air condition in house ventilation motor. I just added 4 magnets in it and it gives me approx. 12 - 30 Volts.
My second dynamo is made from an old water jet pump motor case. I added 4 magnets around it's rotor. I added used washing machine water inlet coils. I used old construction iron bars to fill them and with a diode gate for each coil I have increased the efficiency.
Now this gives me approx. 20 - 40 Volts.
I try to add them to charge 12 Volt Battery(s)
I need an automatic cut off charge circuit where it will give the current out for the leds when in the night I will turn the led lightnings on.
Shortly; my electronic device has to help using battery as a first electric source, has to help the battery to charge from the wind and the sun ( off course I will add solar panels) and has to help battery to charge from the electric network.
I am planning to use
BATTERY MANAGEMENT SYSTEM (LTC6802 & ARDUINO)
Do you have advice(s) ?
Thank you very much for your time and interest.
 

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wayneh

Joined Sep 9, 2010
17,498
The lowest cost solution could be a simple blocking diode on each source, with all sources ORed to the battery. We can't tell whether the dynamos are large enough to damage the battery. If they are, than you will need something more complex.

Do you know the power output capacity of your windmills? It depends on the cube of wind speed, so it would be great to measure the power at a certain wind speed. It also depends on the load, so it helps to vary the load over a wide range to find the optimum.
 

Thread Starter

ouzcoskun

Joined May 12, 2016
32
circuit.gif
I have this diode gates for each coil increasing me the efficiency of the system. Sure I will check more precisely the power of my windmills' dynamos. I just added them in serial to get the most since I do not have any other solution.
 

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wayneh

Joined Sep 9, 2010
17,498
That's very inefficient because there are so many diode voltage drops in a serial configuration. It's not so bad if the dynamos are all producing a relatively high voltage.
 

Thread Starter

ouzcoskun

Joined May 12, 2016
32
With this diode system (used in each dynamo) the efficiency increases because the main problem with the coils is; Each time a magnet get closer to a coil the circulation starts, but since the magnet moves, the direction of the electrical circulation in the coil changes its poles. And with this diode gates I got the maximum power from each coil, anyway the circulation poles are the gates are correcting them. But I do not know how to add dynamos and even solar panels one to another but serial.
 

wayneh

Joined Sep 9, 2010
17,498
Adding your dynamos in parallel (after rectifying) is an option but of course the choice depends on the dynamos and the load you are powering.
 

Kermit2

Joined Feb 5, 2010
4,162
You may need to add a relay and a "dump load" to the system.
Solar panels only might not need it, but in the months with high winds, wind generators tend to output more power than the batteries can take. When fully charged the relay "dumps" the wind generator output to another load, usually a heating coil, to prevent boiling away the battery electrolyte.
 

Thread Starter

ouzcoskun

Joined May 12, 2016
32
Thank you very much for your note. The charge circuit is already controlling the voltage with LM317 regulator and stopping the charge when it is over 12.50 V. on the battery. (approx) Do you still think I need this relay and dump ?
 

Kermit2

Joined Feb 5, 2010
4,162
Just disconnecting the source from the batteries will protect them, but without a load to provide resistance, the wind generators could over speed and damage themselves in high winds.
That is why a dummy, or dump load is used. One could just short the genny's output together and accomplish the same thing, but it is hard on the copper windings to short the output during high winds.
An old heating element from a stove or water heater can work well as a load.
 

wayneh

Joined Sep 9, 2010
17,498
Many windmills incorporate a mechanism to take them off wind when the wind velocity is excessive. An electrical load acts as a brake on the rotating blades, but that might not be enough. The wiring in the generator and/or the load will eventually be overwhelmed at some wind speed. It's a very "sharp" effect, since the available power in the wind goes up with the cube of the wind speed.
 
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