Convert Alternator to Brushless Motor 

If I understood that right, the voltages on the rotor are trial and error, limited by the 12V on the stator. Is there a way to calculate the perfect ratio for the two voltages? What specs might we need to do that? Is the ratio linear or does it change by the amount of voltage put on the rotor?

finally someone that explanes it in detail. not just a video of them cutting wires removing stuff and never saying a word. thanks i am going to try this today.

You’re the best presenter because you talk as you demonstrate. Others are doing like magicians. Its up to the viewer to interpret if he is good enough to pick up.

Actually, the voltage on the rotor will only influence the maximum torque the "motor" will exhibit. The reason speed is lower when using two cells to power the rotor is that the rotor draws too much current, hence a drop of voltage for the electronic driver which feeds the 3ph stator. This is why there is an electronic regulator to control the rotor current. The way to set the current on the stator is you must feed as much current as necessary so that no slippage arise. Some 3ph drivers have a power input separate from the supply input such that you can put the power input in series with the rotor winding. This way the rotor is then feed with a current dependent on the power required by the driver. Otherwise you need to drive the rotor current determined by another electronic circuit. Or use a resistor to limit the current, but this method will loose battery power into heat from the resistor. Be careful not to feed too much current into the rotor for it can easily burn. Great video. Thanks for sharing.

RU-vid is a 5 star app to me, and very helpful in showing DIY video’s

The two brushes connect to the the slip rings on the rotor. What you call the "Middle part ". It rotates, and is a rotor. The stater is stationary and outside the rotor mounted in the housing.

I keep coming back to your video because you get to the point without telling me how good you are. Really appreciate the simple list of components required

This is an excellent video despite some of the terminology being wrong (as various commenters have pointed out ad nausea). I like the fact that you showed exactly what you were doing and the result. I have some theoretical background in how everything works so I don't care about all that. I just wanted to see how you take it apart to get an idea of how complicated the process is. Keep up the good work!

The center part that spins is called a "rotor", because it rotates.... sometimes it is called an armature. A stator is from the latin root word "static" meaning it does not move... it is the laminated iron part with copper windings around the outside of the device. In this instance the stator is obscured by the casing. Also, you put the brushes back in, so not really brushless eh?

You need to re-title this. "How to use a car alternator as a motor with electronic speed control" maybe? To make it brushless you'd need to replace the wound rotor with a permanent magnet one.

I had been thingking about using ESC for controlling motor 12v alternator, finally I found on this video, this is the answer, ok thanks for your share

Cheapest way to power up a DIY small multihull fishing 🎣 platform. Recycling Alternators to motors......... thank you for sharing your videos. I can use this information to power my home built boat 🚣‍♀️. Peace

At 5:15 ,The copper slip rings are not for the stator. They provide a current path for the field, which is wound on the rotor. The part that spins. The field requires only a small current to excite the main output coils that are wound on the stator ; the stationary coils, which produce 3-phase alternating current. The diode- triple converts the A/C into ripple DC, which charges the battery. Vehicle alternators do not make efficient motors. Not designed for that purpose. The pulley shaft on most of them are not even keyed for the purpose of driving the pulley, but rely solely on the shaft nut to squeeze the pulley to the shaft. Even under load, the rotor does not require a large amount of torque to rotate. Real motors require a key way or spline shaft to drive a load, as well as a ruggedly built rotor.

Very bold and with rudimentary tools. Scrap yards cur the wire coming out of the alternator because unscrewing the nut usually break the insulator. I recommend grinding the nut. (Penetrating fluid may work but you usually end up breaking the insulator. Then game over! )

Thanks a lot for this video. I knew the theory of converting alternator into a BLDC motor but I was not sure about overheating by lower RPMs (which means lower frequency.) One of my customers asked me how to do that so I sent him Your video. You did really good job.

Great video awesome information and great walk through, grab a few more tools and a few more connections lol

Those funny little screws are Torx screws. You need a Torx toolkit.. 👍👍🙂

Good job in describing/teaching. I've been trying to learn how to do this and I understand so much better now.

The middle part is the ROTOR because it ROTATES. The clue is in the name. 😉

The local scrapyard should sell you a good alternator for less than you paid for that one.

The coil in the middle is called the rotor. Those brushes are at if not very close to end of life. You should have to load them with spring pressure to make sure there is contact. You could have intermittent contact if they are super worn and judging from the strong moon curve in them, they are pretty worn. The STATER is the larger windings that run along the outer part of the workings. The plus terminal on the brushes is called the field. Typically controlled by the voltage regulator, (That piece you broke off) working in a way that a small applied voltage renders a multiplied voltage on the output, provided the rotor is turning. I'm questioning if the voltage to the rotor was backwards but it was hard to see how you had them wired to the battery pack. FYI, you don't even have to run a power rotor, you can replace the coils with magnets, like a motor. I used to work on an assembly line for a reman shop. I found this video pretty educational however.

Changing the field voltage (the dc voltage) is like changing the motor Kv. Higher voltage means lower Kv and lower voltage means higher Kv. Permanent magnet motors can't change Kv on the fly but this type of motor (with a wound rotor and controllable field) can.

Good Video Young Man & by now i think you know the Diff between Rotor & Stator Great work!!

Bring out all 6 wires, and you can switch between delta and wye on the fly, and basically have a 2 speed motor.

nice one. Thanks for sharing your knowledge

No need open the coils, nice explained, Thank you

Yeah theading for this video says converting an alternator into a brushless motor when in fact its not brushless because he installed the brushes back in the alternator. Just a little FYI for those of you that didn't catch that so it isn't infact a brushless motor as advertised.

You incorrectly refer to the rotor as the stator. The rotor is the magnetic field created by the application of 12volts DC or less to the brushes. It rotates, so it is the rotor. The stator is a 3 phase array of windings which is supplied with the main motor current. It doesn't rotate so it is the stator. The high current to the stator is controlled by the ESC which puts out a 3 phase AC pulse width modulated current.

First off, good work on your project. Just want to clarify that delta or wye configuration don't effect the speed of the motor and mostly are used for starting and running currents. Also you can't for sure tell the difference between how they are connected on the inside by just observing 3 wires, since both configurations will have 3 leads out. Best way would be to separate all the coils and do ohm check to determine the true configuration. Also since alternators don't have magnets inside them, you are feeding the rotor a small voltage to create the magnet, and doesn't mean you need 48 volts to run the motor. When voltage is high, you have higher magnetic effect and your driver doesn't have enough current to overcome the magnetic field generated. A drive with higher current output should do the job, most alternators will produce around 90A, so somewhere around that number would make the motor work too.

Rc brushless motors spin faster in delta configuration that's why they use more amps than y configuration

I wish you would explain more are you connecting body of alternator with hot wire from battery??

Awesome really love this subject

Just wondering why the title says “brushless”

WHAT AN EXCELLENT VIDEO! MAKING A BRUSHLESS ELECTRIC MOTOR CAN HAVE MANY APPLICATIONS. I BELIEVE POWER AVAILABLE IS ONLY BASED ON SIZE SPEED CONTROLLER YOU CHOOSE, AND THE AMOUNT OF BATTERY VOLTAGE YOU APPLY.

Friend your effort on this motor is very good 👌 friend

What about a big truck altanator. Semi truck . I'd love to see if I could get one of the to run on a vfd.

Good job. I redid the generator and installed it on an electric car. The video is on my channel.

wouldn't the armature be burning out? having it constantly connected to the battery and the motor not running, while your adjusting things. Do you know what the issues were in the beginning when it would only run then stop , for about 4s? Love you work and channel. I love how you explain every thing while you are working and diagnosing. Thanks Mate, Keep up the great work

Thanks for sharing..great video and instruction.

Thank you 🙏 a lot of useful information.

My man you still have da brushes 😂

New brushes on your brushless conversion? Interesting ! You took off the bridge rectifier and regulator... then sorted the remainder ...Hang on, why are you refitting brushes to that Alternator ? ? ? Aha I guess that you didn’t remove the Armature and fit it with magnets to give it a permanent magnetic field . This is why you need battery power to energise the armature ...

If I am understanding what I am seeing, you are running this on those 3 or 4 and no more than 6 little batteries and you did not connect to any other power source, right? If so I am really impressed with the torque when you kick that thing over! My question is rhetorical - no answer required unless someone wants to correct my understanding or lack thereof. Great and interesting video.

Hi, At 3.30am you told to explain the different alternators in a next video. I have disassembled a stator from a 24V 120A alternator to measure each coil. in total there are now 12 separate wires coming out of the stator. How can I reassemble it into a star configuration? I'd be happy to send a photo if possible. Thanks in advance!

Nice video, good explanation and it's indeed a motor...just not a brushless one...it has brushes on the rotor...

What type of batteries can it use? Wondering because i got a nimh laying around and im planning on building a electric go kart

The Y vs D configuration has nothing to do with rpm. It is the number of poles that decides the rpm.

Not a brushless motor.... You have to apply a voltage to the brushes and energize the coils in the rotor so that it acts as an electromagnet. Then when you run the power from the brushless motor controller to the 3 winding wires in the stator it will run. Regulate the voltage and current running to the rotor and you increase/decrease the strength of the field and vary motor power.

Good stuff. I have an old, but good condition alternator from an old Mitsubishi V3000. I want to maybe make my old bicycle into a E-Bike by using this method.

Call your local pick it yourself wrecking yards and ask how much alternators are, some are crazy cheap as they mainly want the melted scrap value and selling parts is pure gravy.

on this alternator what power of battery will be needed to power a go cart or golf buggy for 50km range. thanks .

Hi! How can I choose the battery for my alternator? Which are the characteristics I should look at? Great video man!

If you take a brush wire and wire to winding and wire the other 2 windings together the one winding is negative and one brush wire positive and only need on 12 volt feed for both

Do u need the ese or can u Olson only run on a batery

Ok I did what you said. But my alternator locks up when powered then spins free after power off? Any thoughts would be great

Good Job , this helps as to understanding the Concept !

"I'll have to buy some new brushes for my brushless motor."

great video! how to connect it if alternator have a 4 wires??? thanks

What would you charge me to build one for me and how do you get it to produce power for a plug 8n

Bro I have an alternator with 4 wires which is in star connection. Can you please help me with the viring?

Hi, thanks for your work on this. Really great. I was wanting to convert an alternator to a motor and run it off a 12V vehicle battery. Would a 48V ESC work? Or would you need a different setup

can't get my head around one thing, how do limit ur speed range, i'm working on the same project more or less, but i'm using an arduino board and a potentiometer, and I still get a really high output frequency of the ESC(1KHZ). I only need 60HZ

incase is hasn't been mentioned the middle part with the slip rings and brushes are the rotor not the stator still well done

Could this alternator now be used as a generator and a motor as in regenerative braking?

Thanks for sharing . Great help

does increasing the voltage to the coil increase torque while lowering speed?

building a bicyckle with my delta alternator,awesome?going to build one for my other bike with a y diagram version,and find me a couple speed controllers?

I would have cleaned my commutator too. Those copper leads get carbon fine buildup that causes issues with consistent rotation down the road as the brushes wear out. I think a battery lead cleaner will help with that, or green Scotchbrite pads.

Hi guys. Would reverse go via the controller? I found a fairly big unit from a Cat engine. It has ac connections on the outside already. Do I still tear it apart?

These are the same tools I had when I was 12 YO, 59 years ago.

I appreciate your details of wiring the alternator. But, you failed to describe or explain how you were controlling it at the end. You somehow setup your remote control to operate it, but what are those details?

I would recommend not removing the fan/blower if you want your motor to last

Good video nicely done. Thank you.

What you call ese is actually esc Electronic speed control

Could a 12v car battery power a 1000w speed controller i have no idea about this kind of stuff

What can you do with the 3 wires if you don't have a speed controller? Maybe just make it run full power?

So basically just doing the necessary steps to switch output to input?

You call it a brushless motor but you use the carbon brush?

WOW nice pile of tools there Chief

I have only one question relating to it being brush-less, i.e.How is it a Brushless motor - if you still use the brushes in it to operate it? You said you'd need New ones. So as far as I can tell you've converted the alternator into a motor successfully - but not a brush- less motor - as such. But why not just use a 12volt car starter motor as a 12 volt motor to power things instead? - just remove all the gear from the starter motor shaft that makes it 'throw in' to the Flywheel and add your own pulleys etc to the drive shaft of the starter motor to run whatever you want to run on a 12volt motor as the Starter motor would be much more powerful - without too much difficulty to convert it to a usable motor instead as it wouldn't require all this tinkering - with the electrical side of things or at least not as much on altering the drive shaft - to make said powerful motor. Having said that though - How long would it take to flatten or run a car battery down using - either motor - i.e. your converted generator one or an alternate car starter motor to power things? I'm more interested in the longevity life of the Battery that powers the motors in any case as it would need to run for hours before flattening the battery. On that side of things I would be even more interested if you could show how to hook up a working alternator to a starter motor and what things may be required on the electrical side of things from a car - to have the car alternator recharge the 12 volt car battery - as the starter motor is operating - whatever needs to be powered. Maybe two alternators could be used - one converted and one not - hooked up together via pulley and V belts or existing pulley or timing belts etc and utilizing all the electrical stuff - like car voltage regulators etc to recharge the 12volt DC motor via the working alternator - whilst the converted alternator motor is running - so the battery life is theoretically extended - so that it is not flattened too quickly. Possible? I dunno? BUT I would indeed - like to find out. :) I would prefer as brush-less motor, nevertheless - but stater motors are not Brush-less and continuous running would wear the brushes out very quickly I should think - hence my interest in your conversion. I have an old GMC 850 watt 240 volt output Generator that I recovered from what was thrown away - that I want to convert to an electric one - just for lighting a small campsite home/caravan and single garage shed located there - instead of a petrol/gas powered one and a relatively new but defunct 240 volt compressor - that I want to fit a motor to - in order to run it 'off grid' as there is no mains power to the country property that I obtained very cheaply - because I'm not permitted to build a house on that camping block. I think the 850 watt generator part of the GMC generator is still intact and operational - but I need an electric motor that runs on a DC Battery - to run it to see if that is actually the case. Hence my interest in your conversion. I also want to fit a motor like your conversion - to the Air compressor to use off grid also on a DC car battery. But since I'm not electrically minded - I find that conversion of yours a little daunting. ;) And the other possible conversion of a car starter motor even more-so. What advice can you give me on my 'starter motor' alternative to the Alternator motor - that I've just stated here, that I'd like to use a DC motor for?

why one would want to turn one into a motor I don't know but it was an interesting video

As an alternator, it will easily put out 100+volts if the regulator is disconnected and rpm high enough (I've seen 6v alternators on small motorcycles put out over 90AC volts, no load). I would think most automotive alternators can also put out around 45amps at low end and vehicles with high electrical loads 100 amps or more. (It's been a long time since 20 amp alternators were 'enough') Therefore, you can put 100+ v into it at lower amps or, high amps at less volts. The stator will need a controller switching each phase to get any decent torque.(or wire it as a low volt 3 phase motor?) In effect, you have a very crude stepper motor or a brushed 3 phase motor. The rotor will only need a small voltage to create a magnetic field, the outer winding's will control the torque.

Thank you!

Bro thanks 4 your vid, could you pls say me if this alternator worked well? and about how much time it worked using what voltage ?

How much tork does it make... could you use someting like this for a boat?

thanks I like this video

does it need to be a working alternator or will a broken one work?

What you change alternator on the side like you said he's one of those have four wires coming out of it so what did you change alternator because of wires did you change alternators honest

This is a really interesting idea, when choosing an alternator are some better than others? For instance would a truck alternator be stronger than an alternator from a smaller car? Are older alternators easier to disassemble? Thanks! Great video.

Is the 3 wires is for the stator?

good job

Yes i wonder what a semi alternator would be as well and if you can put a speed controller on it.

You do not have to take anything else out of the alternasir. What is that mechanism that you that is blue and yellow and the you hook the wires too

I don't have a brushless controller yet but I do have an electric chainsaw that I can no longer get batteries for so I took the control unit from it which is for a brushless motor and all mine does is twitch like yours did at first. Any suggestions

Nice work

I wonder how efficient is it as a motor? How much torque?

Your very smart

Hi. I don't understand how it is brushless as it appeared that you put the brushes back in and connected a red and a black wire to them? Or did I miss something?

Would it be possible using switching relays to switch between motor and alternator functions so it could be used to start an engine then charge the battery whilst running.

Ok i have neodimium magnets, aproximately the size of a quarter. I have a used ford alternator. I have a 1/4 horse 3 speed 1 phase motor. Hopefully after i complete the alternator modification, i will not fry the 1/4 horse motor. Ill post the results. Fyi. The alternator is a 1972 ford 55amp , ill post the alternating current output upon completion. Btw, what is being removed are diode trios(2) and the rest of the wiring to make the alternator direct current. By installing the magnets n.s.n.s.n.s etc you are creating an alternating current generator. The ford alternator im using , previously had an externat voltage regulator. Peace yall. Ill letcha know