24V/36V YIYUN YK31C Controller for brush motor review and manual

Maybe it also happened that the control unit YK31C on an electric bicycle or a four-wheeler or electric scooter.In this article I will describe a relatively good substitution for the old control unit, you will learn the pros and cons, there is also a good manual to connect the circuits to the control unit

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Review Pros and Cons
Detailed description of brush ebike controller YIYUN YK31C
Schematic manual
Technical parameters of brush controller
Buy in shop

Where to buy

Review with Pros and Cons

Now I am describing my experience with the YIYUN YK31C Speed controller for brush motor, I tested about 12 pieces of this product and all worked OK.  Read the pros and cons of this product:

YK31C dc brush motor controller
YK31C dc brush motor controller


  • A small box, will fit almost everywhere
  • It has battery protection, and if the voltage drops, the control unit switches off
  • Compatible with parts for electric bicycles  36V/48V batteries,brakes,throttle and meters.
  • s costly about 10-17 $  even with shipping


  • It’s not completely waterproof (little water does not matter eg rain).
  • In the case of a long-term very high load, it can burn down,(the control unit is small and the heat has no place to escape)

Review conclusion:

It is a good device  with a good price.You pay from 10-17 usd (even with shipping) and you will get a stable device with good performace and with basic funtions.

For long-term high current consumption, the control unit needs to be cooled (Such as a long hill climb).

  • My rating is positive before writing reviews I tried about 12 pieces of  YIYUN YK31C.

The best use this 24V/36V YIYUN YK31C  is for  brush motor this include e-bike,mini elektrobike,electric  cart ,e-scooters and and so on.

Detailed description of brush ebike controller YIYUN YK31C

YIYUN YK31C controller can buy in diferent voltage and watage variation i seek this version in table:

24V 36V 48V
250-350W 250W-350W 250W-350W
500W 500W 500W
800W 800W

  • It ranges from the version of how much current it can bring eg. 24V 350W má maximum current about 25A
  • The controller is stored in the aluminum cover,and secured by cross screws.
  • Cable wires with connectors are about 15cm long
  • On the top of the cover there is a description of the wiring but it is Chinese so I will show below how to correctly connect the control unit
  • Supports the Hall sensor three-wire control throttle
  • In YK31C is used CNX-50 for motor or battery and CNX-54 for throttle , other connector is CNX-54 its good explained on this page
  • The controller has an integrated battery protection, for example, when the 24V system is switched off at 20.5V at 36V it is 31.5V and at 48V jet approx. 43.5V
  • If you need more speed buy yiyun 1000W controller 36V or 48V

Here is manual for YIYUN YK31C Controller  how  to properly plug the connectors

  • Battery :Thick Black (Power Negative) /Thick Red (Power Positive)
  • Motor :Thick Yellow (Motor Negative) /Thick Blue (Motor Positive)
  • Ignition Switch :Thin Red(VCC)/Thin Blue
  • Indicator : Thin red (Indicator power output) /thin black (indicator negative)
  • Brake: Thin yellow (Brake signal)/thin black(Negative Power)
  • Speed governor : Thin blue(Speed handlebar Signal input) /Thin black (Negtive Power) /thin red(5V Positive Power)
  • Charge Port: Thin red (charge input power Positive) /thin black (Power negative)
  • Brake Light: Thin red (power Positive) /thin black (Power negative)
  • Most often works with SLA lead batteries but can also be li-ion or li-po, lifepo4.

Here can  download manual with wirring controller manual for YIYUN YK31C Controller

YK31C diagram

  • An important note when connecting the throttle must be good wires !! Otherwise an electric scooter will not work

On schematic is called “speed governor” is connector for thortle Well see how the wires are arranged

  • First is blue signal wire (Also often marked green)
  • Second is black (- 5V negative )
  • The third one is red (+5V positve)

But on the throttle the most common electrical wires are connected as follows

  • First  is black (- 5V negative )
  • Second is  is blue signal wire (Also often marked green)
  • The third one is red (+5V positve)

Connect the wires to black, red to red, and color to color – You have to reassemble the wires from the connector again.

For interest, you can see the disassembled control unit that I serviced. It is a control unit for the brush motor that does not work.

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Some time ago I repaired an electric quad, I changed the control unit for YIYUN 36V 500W controller but for children’s electric quad bike is power 500w too much.YIYUN not have current limiter  (maybee sport wire can make faster controller) , i add pot to throttle signal wire (green) pot is 3.3 KΩ can you use trim or pot. Maybe a good lower resistor could work well for 500 ohms.

Can use switch on in the third picture key position 1 means that the signal wire goes through the potentiometer – slow speed, position two means that without the potentiometer full speed.

OR can use less power 500w or 250w controller

Technical parameters of brush controller

  • Voltage:  24Volts or 36v or 48V
  • Rated power:  250-800 watts
  • Match Motor: depend on the power version of the control unit (24,36,48, can be 250W,350W,500W,800W)
  • Current Limit:28A+-1AShort Voltage
  • Protection:20V+-0.5V (for 24V)
  • Brake handle: mechanical normally open
  • Speed Regulator 1-4 V(Throttle )
  • Size 102x65x38mm

If you have any questions, write them in the comments

86 thoughts on “24V/36V YIYUN YK31C Controller for brush motor review and manual”

  1. Good work you did translating meaning of the Chinese words.
    Can you explain what is meant by “Brake” only.
    Brake light I understand but Brake is for what intent please.
    Thank you for your time,

    1. Thank to good question
      Brake = Two wires from the brake sensor

      The brake sensor is the most common micro switch in the brake that interrupts the circuit when braking

      When braking, the control unit disconnects the electric motor

      1. Hello

        Brake handle: mechanical normally open….Does it mean that we have to jumper it to get working the motor?

        Thank you very much.

        1. I have the power hooked up and voltage is 25vdc. I have the lock/power/ignition jumped. I can get no voltage from motor wires while operating the twist grip throttle.

          1. j’ai connecter une batterie 24v au cable battery, j,ai connecter un moteur 24v dc aux bornes de motor en respectant la polarité,j’ai relier les 2 fils rougr et bleu ensemble (keu switch,j’ai relier le connecteur speed vcontrole et en tournant la poignée au maximun ça ne fonction pas. OU est l’erreur pour que ça fonctionne
            Merci beaucoup pour votre aide.

      2. Hi. Thanks for the review. It helped me in the connection.
        But I have a question. Do we need a separate battery charger for charging the batteries? Or can we connect normal 230V AC current (as commonly we have in India) directly to change port so that controller take care of charging the batteries by giving appropriate current and voltage?

        1. Hi no 230V dont conect to controller (burn it) , to charge port can connec out from charger 24V or 36V depend on version

  2. I’m curious about the Charge Port connection. Does this mean it has a charger built in and I simply need to put 120V to that? or does it mean I need a Charger and then just use those wires as the Battery connection from the charger? I’m assuming its the second option but I thought I’d check.

    Also I wanted to be able to limit the speed so a small child can ride it, but then crank it up when dad or big brother wants to take it for a rip (electric go kart) I’m assuming a potentiometer in line after the throttle should work for that. I realise it will only limit the power not the top speed (rpm) but hopefully it will work out well enough.

    Oh and I got 48v version, and I’m hoping to wire in a wireless kill switch, is the Ignition connector also 48v or will it be 12v? This effects the switch I get. Could also cause an issue with the main ignition switch I’m realising immediately after ordering…

    Thanks for your help

    1. Good day …on charger port is 48V (if you have 48V yiyun controller) do not connect 110V connection is direct to battery ,, do not put 110v to battery …

      Cann you add potetiometer to green signal wire.

      I not measurerd voltage on Ingnition connector,I have to verify it, I will do a video with the control unit measuring the voltage. Maybe there is only 5V

  3. Just bought the same product, but its not working, the motor runs as soon as I connect the clips. Speed adjust and brakes do nothing. Any helpful ideas?

    1. i have the same problem. once battery is connected motor runs at full speed. no throttle control at all. i have foot throttle and hand throttle and have checked with both but same issue.

    2. Hi I have this as well but it is intermittent . if you move the control box and put pressure on the wire bundle it may be better . problem in mine was at the connector / bad crimp job .make sure all plugs are seated and there are no shorts .

  4. It seems like this module is come with battery charger unit. Wonder if this could be used for all battery types..Sealed acid, LI ion, Ni metal hydride… This for sharing

  5. I bought your product 36V 1000W. Why you don’t specify on the controler very important parameter – amperes (10A, 15A, 20A……..)??????????. Without this parameter the motor will burn down. CORRECT THIS ERROR!!!!!!!!!!!!!! I saw your roller on 8 demountable controler. Where to find the reference to your controler 36V 1000W, there 10 sockets.

  6. Have you seen the yiyun controller going full voltage to motor with no input from the throttle before?

    The first time: Been riding the razor for two days and today all of a sudden it went full voltage to motor as soon as i turned it on. Had to pull a cable off a battery to get it to stop. to troubleshoot I unhooked everything but the motor and batteries and it still goes full throttle. I pulled the controller apart and there is no black/fried spots or smells. ❓

    Second time with a new controller
    Rode the gokart for the two days probably over 1 hour on it. Today I plugged it in to charge and as soon as I plugged it in, it went full throttle again.. Doesn’t matter if everything else is unplugged she still goes.. Wondering if it could be my power switch or possibly something else?

    500w unite motor
    36v 10ah batteries
    12ga wiring

    1. Hi CK,

      these SPD’s are designed for long term use. you can use them for 30 – 45 min and let it cool down.
      Try to replace the MOSFETs (check which one is not functional) an dtry again.

      good Luck.


  7. I wonder, I read here that the brakewires, if disconnected, stop the motor. Does Thie mean that I have to Connect them to drive? I have no brake handles with switches so I just shortcuts the two brake wires?
    Thanks for replying

  8. Hi I m Hanumanth, when I m connecting the battery power to controller the motor running directly at full throttle speed with out giving acceleration….
    Can you please suggest me what I should do…

  9. Attachment

    I would not use this for anything more than a 350w motor at 24v. There is very little difference between the36v and the 48v version. Slightly bigger capacitors and slightly better spec MOSFETs. I will attach a picture of my current unite 800w scooter controller next to the two versions of the yk31s. 5 x low spec MOSFETs with 60v caps vs, 13x decent MOSFETs and 80v capacitors. The wire gauge is also very telling 12awg at best left vs 10awg right. The one the right cost an extra $10.

  10. i have tried to connect the wires like it is said but it does not work. Should I connected a switch to the port and turn it on so that wires will join together then the throttle will function.
    Kindly advice

  11. Hi, I bought a YK31C here in Germany, but my version has much more cable than the Picture above and (maybe all) websites show.

    Do you know a different version of YK31C?

    On my Version there are 3 Wirepairs labeled with brake, 4x red/blak are unlabled, there is a red/blue/yellow/black one unlabled and a blue/red (with fuse) unlabled, than a single yellow, single blue – and two lon thing black, one grey and one brwon cable.

    The label on the device shows it is the YK31C DC36V, 800W, 1-4V.

    Regards from Germany

  12. Hi i have an electric quad and its was all running fine all of sudden it stop working i took it apart and found it all runs on a yiyin yk31c bushless motor and i have power comeing out of everthing but asa i twist the throttle the motor dosent do nothink….so check motor on battery and works fine so brought new throttle and tryed that and still dosent work just can any one help

  13. Hi sir i want to know about brake light connection.
    Can i connect this to a simple led which nornallyworks on 3v such leds can i use to this brake light connector…my controller is of 24v…
    And also sir how can we assure that the battery is fully charged…my charger is of 24v 1.8A…

  14. Hello, can you help me? I have a 24v 250w controller and when i connect the battery the protection fuse burn out.
    it’s like there is a short circuit inside the controller.
    I’m conecting the battery after all other connections.
    Can you tell me what can be wrong?
    Thank you!

  15. I have the 24v 500w YK21c did not connect all wires but scooter works . Problem is no reverse,I checked throttle wires have +5 on red but I don’t have -5 on black , blue only has +5 when push forward button . I’m guessing I don’t have something connected.
    Please advise

  16. lever switch normally open so when you brake contacts close so joining wires on lead would stop motor

  17. I have just fitted one of these (36v 800W version) to an old powabyke & it seems fine. I only did it to get rid of the annoying soft (delayed) start on the original. Although this is an old powabyke it must be a later version as the others had a throttle that stopped with the signal high but this one is the normal type. It would cause the throttle to work in reverse otherwise. If you are careful you can convert those reversed thottles by taking them apart & turning the magnets around.

  18. My 24v/350w brush controller faulty due to use over voltage how can recti
    ify and what possible major fault in ckt mosfet transistor and dual diode ok
    Where maintenance point

  19. What voltage should the charger be for the 24v version. My old charger is 30v thought that my be a little high . Should I replace with a charger that put out 24v ?

    1. Is okey good charger for SLA battery or li-ion , muss have 29.3V not exceed this limit for battery damage , controller is OK

  20. Hi all,
    have you any idea how is controlled the charging process? How is indicated that the battery is charged fully?
    The charging is finished automatically?

  21. Hi Man, nice website! So I got the YK31C controller and the vgeby throttle controller. I am insure if I connected this thing proberly. may I send u some photos? with my adress?

      1. hey yes! I connected the three wires from.the throttle. there are two more.wires from the throttle blue and yellow. I dont know where to connect them. If i connect the batteries the motor immediately starts going instead of being throttle controlled. Do you have a picture of the right connections since u have the same hardware? thank you very much

  22. Attachment

    Hope you can help. Doing my own e-bike design but I get no voltage going to motor. I have tested Throttle and it works. I connected Throttle black red and blue wire to controller black, red and green wire. I am getting 24 volts to the Power Lock. Closed the connection for the Power Lock using a wire to join both leads. When I put a volt meter to the leads that go to motor, I get no voltage even though I am on full throttle. I am attaching a picture. I would really appreciate any feedback.

  23. I have the yk31c all I want to use are the 3 throttle wires do I hook them to the 3 wires from the controller that are together. I have a off/on switch on my positive batt. with a fuse, the only wires I switched are the motor wires so it will turn the motor in the direction I want it to go, iff that matters, but my throttle will not work and I have no other options that I know of, the motor will run with the restart knob, but it’s not what I want. any help would be appreciated. thank’s

  24. Attachment

    hy! my kid was playing with switch back and forth now i’m wondering how this thing is done together to make it work! what kind of scheme would work for me.
    Thanks for healp

  25. hi,

    can you tell me, what resistors are controlling the low voltage cutoff? I need to lower it.

    thank you.

  26. Attachment


    I have the 24 volt 500 watt version of YK31C Board is marked YK31A
    How can I prevent this controller from burning up the Mosfets?
    using a MY1020D motor, the two MEILAI INNOVATION SIN6812 Mosfets
    burned up for no apparent reason. There is no suppression of motor spikes from the load, is that why this controller failed? This seams to be a common problem with this design

    1. Hi,

      Just swap the mosfets with more rugged versions. IRF3077 for instance. They can take 75V and put out 120A each (in theory). The RDSon is very very low, making the consumption 3 times as little as the SIN6812 FETs. The FETs won’t get warm at all in that kind of design.

  27. Hello, I have Yi-Yun 36v 1000w motor controller. What does the “Sport” connector (small yellow & small green wires) connect to? And if I don’t have a power lock do I need to connect those two wires together for operation?

  28. I have the YK31C 24v 500w controller and a 24-36v 450w currie brushed motor .can I use a 36 v battery with that controller.

  29. hello I plan to buy a yk13c but I wanted to know if instead of a throttle grip we can use a magnetic sensor mounted on the pedal? thank you so much

  30. Attachment

    Or is there someone who can help me with schematic of this second board to rewire it again because im not sur that its wired right, i dont know how to wire the motor , cells , brake …. Because the wire are not labeled

  31. My motor does run very slowly, measured battery 36 V but YK31C comes only 4- 5 Volt out with throttle max

    Could this be a contact problem or bad mosfet?

  32. pls advise
    i am using my ebike for many years

    suddenly now i have a failure
    when i switchon the driveunit the motor immedeately the motor start running without moving the trottel.
    the speed is moderate and when actuating the trottel the speed can be increased ore degreased as normal
    when i disconnect the plug of the trottel the motor stops.

    pls advise do i have to replace the trottle or the contorunit YiYun tech model yk31c

    could you make me an offer

    regards jan willem buitenhuis

  33. I am in need of a brushed 36 volt 800 watt controller with high and low range.
    I can find lots of single speed controllers but no two speed controllers.

  34. Can i use the indicator plug to connect all the lights and horn in my scooter? Or is there a current limit for this port? Would it be better to connect them directly in the battery in parallel with the controler?

  35. Just purchased a YIYUN YK31C Speed controller for a project – however after purchasing I noticed there isn’t a reverse set of wires from the box. I was wondering if I use a twist throttle (motorcycle type) with the forward and reverse switch if it would work on this controler.

    1. Controller not has reverse , but many scooters has big reverse switch on wiring to motor for change polarity ,you can change polarity with relay , coil trigered by switch button on throttle

  36. I have a YK31c Controller to a MY120 500 watt DC motor . i have connected all the wiring as per the diagram . the motor runs fast ,the throttle does not function .
    Any advice ??

  37. What type of plug-in connectors are on the YK31c Controller? – Need to make up my wiring connection using the same plug connectors.

  38. I got the well it says 500w yk31c controller with a 450Watt conversion kit, I’m curious about getting a bit more power out of her, can I really increase to 36 volts and or 48 volts?

  39. Hello, thanks for the excellent write-up. I have a unit with the same model number, but it is 12v. I’ve used it sucessfully to repair a Razer 360 trike thanks to your help.

    I do not understand your example of a children’s quad bike. Why need to limit the current? The controller only delivers what the motor demands?

    1. This control module has good performance for small children 5-7 years old it will be a lot, it depends on the level of the rider

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