0:31 I've never seen a motors looking so happy before

I don't know if anyone has explained this yet, but the problem is magnetic induction in one moter feeding inverse flow into the other. It is creating an oscillation back and forth between the two. As one spins faster than the other it acts as a generator to the other. This is demonstrated when you turn one by hand the other rotates in the opposite direction.this means the moters are constantly fighting each other. If you wish to run two on the same controller you could try either run them in series while doubling your voltage or add some capable diodes to prevent backflow. I would recommend two moter controllers however. One side effect of this is the dynamic breaking, so coasting would be an issue.

The wise thing to do would be to use two speed controllers and two motors connected to a single throttle source. That's how quad copters are built. Each motor has its own speed controller, and the speed controllers are synchronized when you calibrate throttle position.

I'm happy to see that I'm not the only one who knows about amp load increasing to cook the speed control under load.

I know this video is from four years ago. In that time period commercial e-bikes with dual hub motors have come to market. I have one. Mine is an EMX-Xtreme 500 from Fabulous Ebikes that has two 500w hub motors running on a single KT controller. KT (Kunteng) sell a controller designed to support two motors. In use I'm finding the set-up works really well. With each motor having 80Nm of torque the bike has relatively great acceleration and hill-climbing. On level terrain it appears both motors just share the load put on them by the pedal-assist settings. I can switch on or off the front motor while riding. On level terrain, switching on the second motor does not double the amperage draw. It stays practically the same whether one motor or two. On the EMX-Xtreme 500 the bike comes standard with a 48v 30Ah (1.440Wh) battery. With that I've had real world ranges per charge of 110.4 miles to 156.9 miles. Fabulous Ebikes also sell models with 60v 23.4Ah (1,400Ah) battery and a pair of 750w hub motors, again with a single-controller solution.

By the looks of it, it seems to make more sense just to add a second speed controller ( or one designed for dual motor setups.) Either way, it's still a good experiment and I'm glad you took the time to figure it out so the rest of us don't have to

not even one day past and I had my question answered super cool thanks to ev costumes for your time

Interesting, I had not even thought about the possibility of running two motors on the same controller, but I find it an interesting experiment.

old time big cassette recorder feeling

Nice. I’ve actually did the same thing but instead of one controller I did it with two 48v controllers and 2x 1000 watt hub motors. and rewired the controller to work with one throttle. My goal was for more torque but also gained a little bit of more speed from 28 mph to 34 mph

Running both like this will be fine but they will be noisier under load than normal as no hall effect sensors are used. Controllers are cheap, so it would make sense to use 2 controllers, then you can use the hall effect sensors. They can both be connected to the same throttle without issue.

That was good. He learns the lessons so that we don't have to. Well done. .

Very good vídeo bro!

Like stereo, harmonics on two slightly different frequencies due to the reasons you explained. However your test stand may play a part in this as well but only testing would tell for sure. Also, what if you added a third then a fourth hub on this stand and see what it sounds like then. This test was very interesting. Thank you.

Nice , i think you may Use a chunk diod at the end of the motor on the left to not give a feedback voltage and try again.

Your assertion at 9:29 is very correct. I was very glad to see that you do not recommend doing this. There are other reasons why this is real bad in real word usage. Watch what happens when you connect the 2 wheels to a common surface where the cant readily slip between each other. Or you can try using a chain or cog belt between them. In other words locking them to try to spin alike. You will burn things because the motors are never identical. I did these tests years ago with help from Neu Motors and Castle Creations. The noise you are hearing is a harmonic vibration because of the difference between the motors. Best way to do this cheap is use a common feed to separate controllers. But you can still get fighting between the 2 motor systems because of motor differences. Now I had great results using the hall effect switches as regulators to make the separate motors spin at the same speed and stay synced. But that took more processing from outside the controllers. Now this could be accomplished with the use of Raspberry Pi or the like.

Interesting to watch. Thanks for doing the leg work! Luckily the controller is the cheaper part.

Thanks for a great experiment! Newby here. I was considering upgrade options to a 750W48V folder, adding a 500W36V front hub in parallel on a shared 35A controller! hahaha... Maybe just add a 52V20AH batt-w/blender in a rackbag and upping the controller from 22A to 30A? Seems easier adding batteries to a single controller than adding motors...

Thanks, an extra knowledge

Induction resistance and feed back. The pluses have a feed back and you're feeding them to the other motor, there is a build up which amounts to the "losses" you saw which is around 50% of the power (cycle). Put on diodes and a load cap. Then it will work fine. Isn't the controller and motors miss matched?

Very nice that you show this can be done. Perhaps you could try the experiment again but with a higher ampage speed controller.

Very interesting result! It points to high motor losses and ways to improve it. That fact that total losses are more than the sum means that there are high losses in the controller that increase as more motors are added. This will probably be due to the conduction losses in the controller it suspect, more investigation is needed.

with 2 controllers you still splice in both hall effect sensors for one controll, this is all you had to do and they would sync. In addition they are both running the same direction, one side if used on a trike would require you to swap any 2 wires on the motor going backwards around.

Very good, thanks for video!

I have 2 hubs at 22amps each 36v, I use 2 controllers and one throttle you only need the throttle signal wire on the 2nd controller, obviously, top speed isn't increased but torque and acceleration are great fun but due to lack of weight over the front wheel it spins on hard acceleration from a standstill and the extra weight is a downer. for the extra weight, I'd just buy a new controller with higher amps as long as your battery will take it, but it looks cool with 2wd and lots of people are interested and ask questions if you like being sociable.

Try with wiring 4 diodes (2 for each motor), in order to eliminate feedback loop.

with this sistem you can have a total traction on your bicicle , its a good idea good video

From anywhere I can buy and exact price Good job 👍

I have tried too but in 500 watts and so far so good.

Twin 350w hub motors in fat wheel downhill bike with 24v 500w bottle and rear rack batteries. Rear rack holding controller unit. All cables routed through jumbo alloy frame. Bluetooth the display and speed sensors. Thats a sensible build.

[Update on my build below] Great video and awesome (if utterly confusing and contradictory comments!). I'm trying to build an electric hand truck (i.e. convert one to electric) and although several companies make them, the ones they make are over-built for my purposes and VERY expensive (since they're build for industrial use.) I need one to help carry loads uphill on an elevated boardwalk to lake cabin. As far as I can tell, I want low speed and auto-braking and short duration (compared to scooters, etc). The distance is a few hundred feet uphill x 3-5 trips, the weight is

I would think there would be miscommunication with the hall effect sensors. They have to be able to tell the motor where the windings are but if both motors are in different positions the controller won't send a proper signal to the motors.

Very nice sir, now you kmow im not lying.. We used 1kw controller on 2 500watts hub motor. I think this setup will burn the controller if the 2 motor have load. Thank you sir

I actually thought it would work because the motors are as you said identical. Neet thing to know.

Thank you man! Saved me alot of trouble!

How about mounting it to a common axle? I'm thinking of placing two direct drive motors from a washing machine (which are not the same as these but also BLDC) on the same axle and connected to the rear wheel via a chain. My theory is that if I place hall sensor wires to one of the motors and align them properly in phase they would turn just fine. I'd use a 2kw controller in that case.

id bet that with some sort of suppression it would work. id bet the resonance is because the motors become slightly out of phase and start generating their own voltage which is sent to the other motor and back causing both to oscillate. could also probably wire them in series if you had enough voltage.

Well with old school tech it's supper easy. Never tried with modern motors big enough to run a bike or scooter. However brushless setups in models are possible so long as you stay inside your power limits for the speed controller.

Question someone explain please , i thinking about adding duel hub motors kit to my wheelchair from a factory are the compatible with each other ? I'll like to know before purchasing this unit

Try some big diodes on teh phase wires to prevent induced currents from one motor screwing with the other.

could there be some -off road applications , such as -farming-mowing - hillclimbing , trail riding -ect...that allow for constant "wheel slip"? jeeps of yesteryear were kept in 2wheel drive , -on the pavment-because of simular reason , but off road the wheels slipped in the soft dirt/sand . no problems there , in the 4wheel mode.

As a guess I would say its because of the Motor Sensors. The motos get to a certain speed and one of the needs a slightly differnt timing, but the ESC is prolly only doing the toiming based on one of the motor's feedback, then pulsing it the way it thinks it needs. Another intresting phenomena occured but wasnt mentioned. I noticed when he put load on the left motor, the right hand motor slowed down too. Thats going to be to do with the sensors, ill bet! Did you put the sensor wires in paralel or series? or not at all, or only hooked up one motors sensor wires?

The sound difference is just an acoustical phenomena, since the two motors, even if are same model, are not perfectly equal , so there is some sort of beats between the two sounds that are not perfectly the same

I would like to see behind after he hooks up everything!

well done for the experiment i think we can't run the two motors with one motor feedback hall sensors because it is nearly impossible as you said in your video to have the same position and same speed at the same voltage to synchronize the two motors it is like you run one of the 2 motors without a feedback just rotate the field that is the reason of the crawling and cogging (strange sound) so i think we can run the two motors without problem only if we synchronized the sensors signals of two motor (maybe AND gate for the same sensor in both rotor for example (h1motor1&h1motor2)) so we guaranteed the same position of the two motors

This necessarily was running either sensorless, or with the halls from one motor connected. In sensorless, the determination of motor position will be off, because current & voltage are used to determine that, and connecting two motors obviously throws that off. The result is cogging which will vary in severity from loss of efficiency to burning out both motors and possibly the controller.

You need to add diodes (big ones) between the motors. You have back emf current going from one to another.

Very good explanation thanks for the video my Friend🙌🙂🤝🤝🤝

can i ask something, compare 2 controllers 2 bldc with 1 controllers 2 bldc, which is the best? and why?

Great vid, but would be better if you showed how to have them going in different directions like you would on a trike axle

I knew the experiment result before you started it, because of the physics of running BLDC without sensor. Of course, it's no point in connecting sensors together. This setup will work only in case the motors are ideally synchronized. Any small deviation will lead to oscillation in both motors and reading of feedback by controller will be something weird because rotors are in different positions. This "strange sound" is resonance of this system and in fact it sounds strange not only in resonance. All the time it's consuming excess power to keep oscillations going (but rotors are trying to sync). It's OK to some point when motors are rotating independently without ground contact. If you try to place them on a bike and turn somewhere, there the biggest problem will occur because motor speeds will be slightly different. They can behave unpredictably.

Perfectly fine for a slippery or dirt surface condition riding but not for pavement just like an all wheel drive vehicle in the old days when the front and rear wheels were locked together they bind up and often to get out of all wheel drive you had to back up.

Yes, of course, this is possible unloaded but with any significant load imbalance on either motor your looking to fry some FETs.

And if so how long do you think it will last how long do you think it will run with a atypical linthium battery or even a solar panel.

The explanation to the big loss is magnetic induction. One motor create opposite flow of current to the other motor. To overcome the induction the control produce more current to overcome the induction to make the speed of both motors the same. Thats where the 26w came from. Also the battery will suffer in when you use it with a load.

Hi, I'm only newby and learning from guys like you. I saw that these motors can also be used as power generators!? Could you make a video of parallel discharging and charging on second wheel motor! Maybe on separate switchable set's of batteries as known that is harmful for cells to be drained and charged at the same time. Would be interesting👍 liked and subscribed already

Hi... Just found it. Well done

Cool!! But I wounder if you could run in series instead of parallel.. would love to see this..

Nice video! Wake park,(for pratic wakeboard) wich this two motor like this, to pull like 100kg person for 2 min go and reverse, you think is possible?

Hey, man, I saw in the video that you put both in parallel engines, I have to tell you that if you put a diode on his way out of any of you both engines would take the electric contrast between the two, and he would not stop, no one would move when motor tour. A greeting from Spain and I feel the translation.

Para funcionar em paralelo os motores tem que estarem em perfeito sincronismo

Good to know, thanks for testing this. I've always wondered what a two hub drive would feel like, but figured the added weight wouldn't be worth it. It would probably make sense to have extra weight at the wheels for a very high power / high torque setup in order to keep traction. I've also been wondering if we ran a 1000w mid drive with a 1000w front hub motor would they compliment each other?

Sry if this question has already been answered ... with having only the stator windings in parallel and only one motor having the hall sensors connected to the controller, what are the result in Power consumption? My thoughts ... having dual conflicting input signals is probably having an effect on the controller output. With only one unit giving feedback to the controller, the output frequency will be equal to both units, as the second is purely slave unit with the results being a closer to a doubling of the overall current draw. Now if that slave is proportionally under more load, what is the outcome?

Very Nice

two motors connected in paralel -become motor-generator system with oscilation of mechanical energy between one and another - it cause looses, if they will be on one wheel or even maybe on real cycle - Imho it will fixed by flat and dependent rotation of both motors, without ping-pong energy exchange between motors

I suspect this’d be a lot worse on an actual bike. In this setup, the motors are free to ‘align’ their phases, as they’re spinning in air; on a bike, they’d be forced to travel the same speed (staying out of phase) or, even worse, to travel at different speeds when cornering.

thanks, one question, this kind of motor does not have hall on it right, but if I have two hall sensored motors I could install it with no problem?

This is sound beautiful

Excelente 🇩🇴🇩🇴🌎

How do i make 2 parallel. Hubs and what do I need tolook out for?

Mr EV, apart from the uneven current voltage, are there any other problems, for using two bldcs with one controller??

I tried using two motor controllers and two motors connected to one throttle. There must be some kind of feedback because the two motors spin and the power is good, then the controllers immediately turn off or go into so protective mode and are unresponsive. If I turn battery off and on they work again for about one second. Either motor and controller by itself works fine, but together they somehow interfere. The motors are configured (via activating learning mode) to spin in opposite directions since they are left and right wheels and their mounting locations makes that a necessity.

Please try them in series Please!

Awesome you could make a dual-motor ebike with this!

Brushless motors cannot be connected in parallel or in series. That would only work if the motors were mechanically connected to each other in exactly the right position and the Hall sensors were only connected to one motor. Exactly this is not possible with our intended use. Motors with brushes, on the other hand, can easily be connected in parallel or in series.

I I have one motors already dorms the second motor need to be the same and do I have to add a battery as well ?

how can i move it in two directions .... can move forward and can move backward???

Not sure this is a good idea due to back emf. I would say under load the controller, and probably the motors will run hot and with low efficiency. The controller uses the back emf for timing, and with two motors connected the timing won't be handled correctly. Interesting concept to try, but in reality it won't work well, or for a long period.

Would this work better if you had a 500watt controller as both motors equal 500 watts?

Очень интересно и полезно

yes that will work but remember they are sharing the voltage and current so it wont be double power or speed,it will likely actually preferm in real world worse than a single one unless you get an unlimited controller giving full battery voltage use with a continous 50 amp power handling rating

Yes, but badly. :P I tried this with a controller with hall sensor support. That particular variant ran faster with hall sensors enabled. So I lost a lot of top speed.

Interesting :) so it works but with big losses

im trying to find out the measurement between the spoke holes on my hoverboard hub ebike conversion so i can start to build my rim for my ebike.before i start to drill my holes for my spokes

Oh ya I see. So I am still wondering about speed controller kits for power wheels. I have the dune racer which has 2 motors in the back for the 2 rear wheels. The speed controller kits that I seen only has voltage +- input and voltage +- to motor. So it is going to be parallel if I connect both rear drive motors to one controller. I don't think I want to parallel it. How does traxxas emax work....

Very nice👍

The contrôler is processing the feedback from all hall sensor at the samedi time?

1. Peak current for one motor was 0.95А. 0.95Ax37.7V~=35W this consumption we see when the motor is under load, starts to spin. After spinning up the consumption falls down to 22Watts. 2. For two motors it was 2.2A(82W) and 1.8A(68W). It is 41W and 34W per motor. Thus two motors in parallel are "less power effictive" than one in about 41/35( or 34/22)=1.17(1.54) times. 3. This demonstration shows only basic values. We still don't know what it means in real life for bike or scooter. For example with two motors there can be less speed and more power(higher acceleration, more average speed on rolling road or mountains). 4. 41W is not dangerous for 250W motorwheel. 5. 2.2A is not dangerous for 15A controller. 6. We don't know minimum resistance limit load on controller and don't know the wheels resistans and that is why it can be dangerous for controller. But i think if it works then it can be used after some temperature tests. Why not?

love this

Can please show a simple wiring diagram for this, thanks

Great experiment. Maybe have a bigger controller more amps

0:29 LOL, Looks like a happy face!

Control individual 2 motors? Left or right? For wheel chair...... thanks

Does the speed limiter come along with the throttle? What is the throttle you are using ?

Running these on the same axle will cause all kinds of issues with torque transfer. An equivalent effect being that of wind up in a locked axle on a car going around a corner. Everytime you turn the wheel you're going to be fighting the motors trying to push the wheels straight again.

Try putting the motors in series. If it runs too slow, increase the battery size 6 volts at a time until it runs correctly.

How many volts should have the battery for two motors that each have 1000W of power, connected to two controllers?🤔

I'm interested whether 2 500w bafang geared hub motors would run upto 3000w and pedal like a normal bike.

Maybe you have to put a capacitor on paralel circuit?

Add for bouth motors, one way diode's and they will work! They act like this because one motor is trying to charge the other one so on....they act like a generator...if they have one way diodes, they will work 100%! Ty !