Step 8: Build the charge controller

Now That I had all the mechanical parts sorted out, it was time to turn toward the electronic end of the project. A wind power system consists of the wind turbine, one or more batteries to store power produced by the turbine, a blocking diode to prevent power from the batteries being wasted spinning the motor/generator, a secondary load to dump power from the turbine into when the batteries are fully charged, and a charge controller to run everything.

There are lots of controllers for solar and wind power systems. Anyplace that sells alternative energy stuff will have them. There are also always lots of them for sale on Ebay . I decided to try building my own though. So it was back to Googling for information on wind turbine charge controllers. I found a lot of information, including some complete schematics, which was quite nice, and made building my own unit very easy. I based my unit on the schematic of the one found on this web site:


That web site goes into a lot of detail about the controller, so I'm only going to talk about it in fairly general terms here. Again, while I followed their general recipe, I did do some things differently. Being an avid electronics tinkerer from an early age, I have a huge stock of electronic components already on hand, so I had to buy very little to complete the controller. I substituted different components for some parts and reworked the circuit a little just so I could use parts I already had on hand. That way I had to buy almost nothing to build the controller. The only part I had to buy was the relay. I built my prototype charge controller by bolting all the pieces to a piece of plywood, as seen in the first photo below. I would rebuild it in a weatherproof enclosure later.

Whether you build your own, or buy one, you will need some sort of controller for your wind turbine. The general principal behind the controller is that it monitors the voltage of the battery(s) in your system and either sends power from the turbine into the batteries to recharge them, or dumps the power from the turbine into a secondary load if the batteries are fully charged (to prevent over-charging and destroying the batteries). The schematic and write-up on the above web page does a good job of explaining it. Much more information on building the charge controller, including larger and easier to read schematics, can be found on my web site at http://www.mdpub.com/Wind_Turbine/index.html

In operation, the wind turbine is connected to the controller. Lines then run from the controller to the battery. All loads are taken directly from the battery. If the battery voltage drops below 11.9 volts, the controller switches the turbine power to charging the battery. If the battery voltage rises to 14 volts, the controller switches to dumping the turbine power into the dummy load. There are trimpots to adjust the voltage levels at which the controller toggles back and forth between the two states. I chose 11.9V for the discharge point and 14V for the fully charged point based on advice from lots of different web sites on the subject of properly charging lead acid batteries. The sites all recommended slightly different voltages. I sort of averaged them and came up with my numbers. When the battery voltage is between 11.9V and 14.8V, the system can be switched between either charging or dumping. A pair of push buttons allow me to switch between states anytime, for testing purposes. Normally the system runs automatically. When charging the battery, the yellow LED is lit. When the battery is charged and power is being dumped to the the dummy load, the green LED is lit. This gives me some minimal feedback on what is going on with the system. I also use my multimeter to measure both battery voltage, and turbine output voltage. I will probably eventually add either panel meters, or automotive-style voltage and charge/discharge meters to the system. I'll do that once I have it in some sort of enclosure.

I used my variable voltage bench power supply to simulate a battery in various states of charge and discharge to test and tune the controller. I could set the voltage of the power supply to 11.9V and set the trimpot for the low voltage trip point. Then I could crank the voltage up to 14V and set the trimpot for the high voltage trimpot. I had to get it set before I took it into the field because I'd have no way to tune it up out there.

I have found out the hard way that it is important with this controller design to connect the battery first, then connect the wind turbine and/or solar panels. If you connect the wind turbine first, the wild voltage swings coming from the turbine won't be smoothed out by the load of the battery, the controller will behave erratically, the relay will click away wildly, and voltage spikes could destroy the ICs. So always connect to the battery(s) first, then connect the wind turbine. Also, make sure you disconnect the wind turbine first when taking the system apart. Disconnect the battery(s) last.
<p>Hi there, I need some help, I have a 30v ametek motor that delivers 12/24VDC, and a charge controller to handle 12/24v and 20amp, the controller input is only negative and positive, originally made for solar panel, no dummy connector, the question is if I could use it installing a dumm load between the ametek and the controller, I will also install a blocking diode. Could someone confirm this please ? regards, Juan</p>
Hi there, <br>Quick remark on shorting out the motor to brake. Although this method can be used, it is not very good for the motor. When shorting out a motor you dissipate the power (100 Watt and more) over the resistance of the internal windings. This energy is dissipated purely by heat, so the windings get very hot and can damage the insulation. Damaged winding insulation makes the motor useless, so be careful. If you only do this very seldom, I think it wont hurt, especially when the motor runs much below the nominal speed.
im planning on building a tree hiouse. and i think htis would be perfect for suplieing electricity for it. is there any way i could convert the electricity coming fromt he turbine into an electric outlet? if anyone oculd hlep that would be sweet.
I'm not really shure you can turn it in to ac from what I've read I think its only gona be dc o and to let you know for the future you spelled supplying wrong <br>
is gonna a new word?
<p>yah i know - you could spend an eternity correcting bad spelling and grammer - you might as well hold back the tide with a spoon.</p>
<p>Yuppers. And so is 'Ustacould' an 'Ta' an 'DaKine' an 'Jus' an 'Opala'...lol</p>
by using a battery, inverter, and transformer, you could make an uninterruptible power supply of sorts, witch would be charged by the turbine when not in use- then convert (or invert) the dc power from the battery into ac, then through a 1:10 step-up transformer (assuming you are using a 12 v car battery) to the load when needed. hope that helps.<br><br>brief synopsis:<br><br>turbine====battery====inverter====transformer=====load
* <br><br> add a diode here<br> /<br>turbine====battery====inverter====transformer=====load<br><br>( so that the battery does not turn the turbine backwards)
even easier, car battery and car power inverter to invert 12 vdc into 120vac plus it already has the wall outlets for you, the only other thing you'll need is a cigarette outlet for a car and hook it up to the battery<br><br>turbine==rectifier==charge controller==battery==cigarette outlet==inverter==playstation 3 and Flat screen LED TV + friends and beer!!!
I'm sorry I don't really understand
<p>I found a very interesting article about the 3 most important things about wind energy and what to look for when you want to buy a wind power system <a href="https://www.patriotdirect.org/3-things-you-need-to-know-about-wind-turbines/" rel="nofollow">https://www.patriotdirect.org/3-things-you-need-to-know-about-wind-turbines/</a></p>
<p>Since the swept area of the blade is what does all the work, you could get a lot more force out of these blades with a slight change in orientation. It seems like a lot of the blade is perpendicular to the wind direction which means it's not doing anything. Also how do the blades bend or twist when under load? Because if the leading edge were to twist back ever so slightly they would be creating drag in the wrong direction. I think that would be the advantage of attaching the blade by the leading edge, any twist would be to your advantage</p>
<p>ok i'm building a solar power and wind turbine set up.go on amazon and get a 10 dollar charge controller hook a dc motor to the charge controller(wind mill) it has a diode and voltage limit built in.then from the charge contoller to a 12v battery.then hook a 12volt to 120volt inverter.to the battery the charge controller protects the battery from over charge.when the sun shines or the wind blows the battery gets charged.so you will have power at all times.also on amazon for cheap you can get a slip ring to keep the windmill wires from twisting up.hope this helps.</p>
<p>Hi Guy's I am on with building a wind Generator to power my Garage from a Battery Bank, I have a Permanent Magnet Motor which came from a exercise machine, it works from 100V &amp; is Rated at 200W, when I turn it with my battery drill it is throwing out around 36 to 40 volts, will this do to charge my battery bank?? Cheers.</p>
can we upgrade a small capacity dc motor by by wounding more no. of turns to stator. please reply...
<p>Mr. Davis, I have a question about changing wind direction. How many times could your turbine twist around before it damages the wire going down the inside of the tower? Think of a flag that has been wrapped around a flagpole by changing wind direction. If this tower is set up and taken down with your campsite, then this may not be a major problem, but if it's a more permanent installation, then it could potentially start a fire, I think. Don't commercial turbines have some sort of swashplate arrangement that lets them rotate freely without this concern?</p>
Nobody responded to your question, so ill help a bit. Research &quot;Slip Ring&quot; and you might be able to solve your problem. You might be able to engineer one out of conductive materials and insulate the exterior to keep from damage, short circuit, electrical shock...
Just a quick question, it didn't look to me like you had any sort of battery on there. I don't know a lot about this stuff, but as consistent as the wind is, wouldn't you have issues with not having any power being fed to your laptop and other stuff when the wind isn't blowing? Even with the controller, did it still make lights and things flicker and have periods of no power? <br>Fantastic instructable though, very in-depth and easy to understand.
<p>i imagine a solution to the inconsistent power coming from the turbine would be vehicle batteries, they would receive the power from the turbine inconsistently, much like an alternator in a car, and then the power would be distributed with a steady flow from the batteries to the laptop or lights. if you want a higher voltage than the typical 12 volt car battery, you could simply join several batteries together and/or use a transformer to receive the desired voltage.</p>
<p>at a 25 mph wind how many kilo watts per hour would this produce </p>
<p>Thanks for the instructable! Here's mine</p><p> <a href="http://www.instructables.com/id/DIY-Wind-Turbine-2/" rel="nofollow">http://www.instructables.com/id/DIY-Wind-Turbine-2...</a></p>
<p>can 12 volt DC motor produce at least 60 watt ? </p>
<p>see this link for more help </p><p>http://a13b2p5kghw10m9deflkvdgz1v.hop.clickbank.net/</p>
wow thank you so much you just might be a genius lol. I need enough electricity to power a medium size lighting system, and pumps for a hydroponic garden do you think this will do the job and if not what do you think I will need to do to make it work?
Fisrt, I take my hat off, your project is amazing. I'm building one right now, i'm done with the main part of the charge controller. Have 2 questions for you. <br>1.- What total resistance and wattage should use for dummy load. whats a minimum safe, supposing i'm using a generator just like yours? <br>2.- i want to connect a wind turbine and 2 solar panels, how many amps should have the blocking diodes to be on the safe side? <br> <br>Hope you have the the time to answer and i appreciate that you share these things, hopefully we can make this kind of energy affordable for more people (i live in a third world country, buying this stuff new costs a literally a fortune). <br> <br>
While your charge controller will charge batteries, it has no topping charge circuitry. Because of that, your batteries will not last as long as they could. Given that they are a major expense, it may be worth while to buy a commercial one or add the necessary circuity.
Thanks for the post, and I was surprised to see how many different kinds of <a href="http://www.tlgwindpower.com" rel="nofollow">wind powers</a> you can make for your home that are cost effective.
You were stuck building a <a href="http://www.globalmoldinc.com/global-tri-pac.html" rel="nofollow">tower instead of packing</a> for your vacation? Very devoted! Way to go! Thanks for the article! It's great!
can we buil the wind turbine without the charge controller
That depends. Can we destroy whatever we connecct the turbine to?
I have a question regarding the 99v ametek motor and charge controllers. So far I have only been able to find charge controllers that accept 12, 24 and 48v dc as input from either a wind turbine or solar panel. So what if anything needs to be done to step down the voltage from 99v to 48v dc to the charge controller? Or do I even need to change anything? Can I just wire the 99v ametek dc output to the 48v charge controller?
Unless you gear it up, your 99v Ametek will only be producing 30v MAX at wind turbine speeds. A 12v charge controller will handle this easily.,
I have a 180v 4000rpm dc motor from a treadmill. <br>will this work better? <br> <br>Thanks.
Well if you were to do the math, 180/4000=12/266. <br> <br>Yes. That will make a fantastic wind generator. <br> <br>Seriously people, the algebra's not that hard.
Thanks, I was just in a rush.
K so I'm just a kid with out a 1,000,000,000,000 dollars and what to run an old fan motor as a wind turbine attached to my roof with power cables coming through my window to power my clock and charg my iPad I have it drawn out in my head I just need some help of how I get it rotating and producing power I have no clue how to set this up to make power plz help
You really can't use a fan motor because it has no magnets in it.
does it now? (all electric motors require magnets to work)
&nbsp;More accurately&nbsp;electric&nbsp;motors require &quot;magnetic fields&quot; to operate. Prior to the advent of modern Permanent Magnets ,DC motors used electromagnets to provide the stationary field. Light&nbsp;weight&nbsp;DC motors where an exception to that. There where AC motors of similar construction, you will still see those in corded power tools, often these are 'universal&quot; motors, meaning the can operate&nbsp;off&nbsp;AC or DC of the same voltage, <strong>UNLESS </strong>they have a variable speed control, then using them with DC&nbsp;generally&nbsp;fries the speed control.
AC motors dont have magnets, pull apart an old box fan and see if it is magnetic, it isn't. What you could do kid, is go to radio shack and buy some magnet wire also called enameled wire and make your own DC motor, take apart an old 80mm computer fan and look inside, that is basically what you will be building. The only other thing is to get your parents to buy you some neodymium magnets off ebay. then look at this instructable on how to put it all together.<br><br>http://www.instructables.com/id/DIY-1000-watt-wind-turbine/<br><br>It's not as hard as it looks and you dont need all that resin to hold everything in place, especially if you get the counter sunk neodymium magnets that you and screw onto a piece of wood, obviously your not trying to power your house but this instructable will tell you how it works and how to build one from scratch. hope this helps<br>
Your just a kid who doesn't have 1000000000000 dollars, but you still have money to burn on an Ipad :)
do it yourself - http://www.umeluieruki.ru/
For an extra power source during calm weather, could you cover the blades/tail in solar panels?? :) <br>
You probably could, but they wouldn't really be worth it. For one thing, most cheap solar panels are flat, which doesn't work for catching the wind. For another, if you put leads on the solar panels, they would become tangled and cut really fast. Also, when they are placed vertically (such as on a blade), they catch sunlight for only a short period of time. In fact, the extra weight on the blades would probably lessen the power produced. You would be much better off by putting them on a flat surface or in a panel.
Here is an easy yes or no question. Will the char controller work for any motor of any voltage rating? Mine is a 120 volt DC motor salvaged from a blender (If that helps any).
i can used motro ca,?
hi i can get hold of a pillar drill easily, it is rated 1420 rpm and 240 volts,<br>so 1420 divided by 240 =5.92 rpm - per volt <br>would this be a good motor/generator for a wind turbine? <br>
hi just wondering, if a motor is producing a DC current to charge a battery then is there any need for a rectifier/bridge rectifier to stop the charge from the battery reverting to powering the motor?<br>thanks.

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