# Parallel and series generator and batteries

Discussion in 'Power Electronics' started by Buckeye, Oct 23, 2016.

1. ### Buckeye

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Oct 23, 2016
I am trying to build a wind turbine to charge batteries and would like a 24v 12amp output. I am using a double turbine set up along with two batteries to charge. The generators are both listed as 12v and 6amps. The two batteries I am looking at are rated 12v 12amps. I will have the two turbines in parallel and the two batteries in series. If my understanding is correct, the turbines in parallel should produce around 12v and 12amps combined. The batteries in series should produce 24v and 12amps. Therefore I should reach my goal of 24v and 12amps.

I have been having trouble finding circuits like this online. I am not worried about the rpms of the generator right now and will have blocking diods to prevent the energy from the batteries going back to power the generators. I need help figuring out wether or not this will work without building the setup first. If I am missing something please tell me.

2. ### duke37

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Jan 9, 2011
To run a 24V system the batteries and also the generators need to be connected in series. You need similar turbines with the same wind speed.

3. ### Buckeye

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Oct 23, 2016
If I put the generators and batteries in series I would get 24v like you said but I need 24v and 12amps. If I put the turbines in parallel ( 12v 6amps + 12v and 6amps = 12v and 12amps) and connect them to the series batteries ( 12v 12amps + 12v 12amps = 24v and 12amps) would this work? And yes the turbines will be the same along with the wind speed.

4. ### Bluejets

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Oct 5, 2014
Parelallel 12v is still 12v.....no good for 24v.....series gen sets might give you a headache also... re. Regulation. Don't know what your reference to batteries rated at 12A means....usually they are rated at Ah.

5. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

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Jan 21, 2010
The easiest way might be to have each turbine charge of battery. This assumes they have similar output and both are on-line.

6. ### Buckeye

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Oct 23, 2016
I want to put the generators only in parallel. I know that in parallel I will get 12v and I want the generators to produce 12v. My question for the generators are because they are in parallel will the amps add together to produce 12amps? Both generators are 12v and 6amps each.

When I mentioned 12A for the battery I meant 12Ah.

7. ### duke37

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Jan 9, 2011
If the generators are identical with identical input speed then they can be connected in parallel and you can add up the currents.

If the speed is not enough to produce 12V then no charging will occur. You may not get 6A unless there is a gale.
It is possible to use a device to optimise output at varying speeds.

8. ### Buckeye

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Oct 23, 2016
Thank you, that cleared up the confusion with the generators in parallel.

What kind of device would optimise output at varying speeds?

9. ### duke37

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Jan 9, 2011
Look up
wikipedia
Power optimizer
Maximum power point tracking MPPT

I have not played with these. There are devices on ebay which will charge two 12V batteries.

10. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

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Jan 21, 2010
I would recommend that you isolate the two generators from each other with diodes.

11. ### BobK

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Jan 5, 2010
If you put the generators in parallel you will not have enough voltage to charge the batteries in series. You cannot charge a 24V battery from 12V.

I agree with Steve that each generator should be connected to one of the batteries.

However, you are going to need some kind of a power controller in between.

Bob

12. ### duke37

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Jan 9, 2011
I see no necessity for this, if the generators are simple DC machines, in parallel they will run at the same speed which will be as they would naturally run in similar wind conditions. If they are rectified alternators, they will have the diodes built in.

13. ### Bluejets

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Oct 5, 2014
Have to remember they usually contain some type of regulator which depends on battery potential to operate correctly. I go with Bob.

14. ### Buckeye

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Oct 23, 2016
I found this picture online that shows what I was thinking of building. The two turbines are connected to the batteries, but I can not tell if the turbines are in parallel or not in the picture. If they are I will base my design off of the picture.

I will have to add diods to the circuit.

15. ### duke37

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Jan 9, 2011
This is what Steve suggested many posts ago.
The batteries are in series also the generators.
Each generator charges its own battery.

16. ### Buckeye

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Oct 23, 2016
What would the picture look like if I wanted the generators in parallel and the batteries in series?

17. ### duke37

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Jan 9, 2011
It would not work, why are you fixated at running the generators in parallel which can only charge one battery?

18. ### Buckeye

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Oct 23, 2016
I wanted to have a final output of 24v and 12a. To achieve this I was thinking that I could use two 12v 6a generators in parallel to get 12v and 12a. Then that would connect to the two 12v 12Ah batteries in series to make it 24v 12Ah.

What components would I need to change to achieve the 24v and 12a? Would I have to switch the generators out for a single 12v 12a generator. Then put it into the series batteries to get the 24v 12a.

19. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

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Jan 21, 2010
Two more generators

duke37 likes this.
20. ### duke37

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Jan 9, 2011
You are getting confused between A and Ah.
12V and 12A = 144W
24V and 12A = 288W
Where does the extra power come from?
You need an extra two generators as Steve says.