Help please on slow speed of wheel

[milly]

Hi,
I hope someone can help with my problem. I just built a tricycle into a electric one for a friend who had a stroke and when turned on it runs very slow once you turn the throttle.
I am using a front hub motor a brushed one poss powabyke, a new controller and new throttle, controller is for a brushed motor. With the front wheel off the ground the wheel hardly moves at any speed ( can even be stopped by hand).
I have so far upgraded the wire I was using incase it was to thin tried a different throttle wired 2 front hubs direct to battery pack and they both turn fast, replaced on/off switch with a battery isolator switch and its still the same .
The controller is a 36v 250w 15a it is a yiyun tech yk71.
I shall give you details of how I wired it I do not have pics.
The wiring code from controller was translated by a tiawanese friend for me as it was in chinese.
Speed limiter black and black, brake yellow and black, throttle red+ black- blue signal, power thick red+ thick black- motor thick blue+ thick white-
I wondered if the motor and power wiring may be conected wrongly (i.e. power is really motor supply ) as she said the translatation may have a mistake which she made. I dont want to swap round and blow it if not
I hope someone can help and its something simple I have missed
Many thanks in advance for any help you can give.
Milly

 

[Punx0r]

Yikes.

Have you taken voltage measurements of the output from the controller to the motor? Throttle signal voltage?

Is the throttle the correct type for the controller?

 

[Dauntless]

Just guessing, but if it's a 26" wheel it's probably spinning around 150rpm and getting you 12mph on it's best day. If it's doing less than that it's hard to say much before checking connections, battery power, etc.

 

[e-beach]

Hey milly!



Lets start like this....Do you know the motor is good? If so how do you know?
I have your controller as a 24v controller. Did you plug a 36v battery into the controller?
http://www.tncscooters.com/YK71/YK71.pdf

Pictures are very helpful around here....Just keep the file size under 500kb so you can post them without a problem.

 

[Ykick]

Wow, 3 years - long time no see....

This would appear to be your controller:
http://www.tncscooters.com/YK71/YK71.pdf

If it were my problem I'd check voltage Motor connector (blue/white) under WOT with the motor disconnected. If close to battery pack voltage then check with motor connected.

Voltage will deliver wheel speed as long as enough current is available to spin the motor up.

 

[dogman dan]

Apparently the motor spins good, with good torque, if connected direct. That pretty much eliminates the possibility of it being a brushes problem.

Unless there is a very poor connection to the battery, looks like you got a winner on that controller. Fortunately, controllers that size are very very cheap.

I'd be inclined to just try another myself. One possibility is that the throttle out wire is only 1v. That's the red wire to throttle. that would make full power 5v signal back in impossible. If the red isn't 5v, the blue cannot be 0-5v.

You don't have that speed limiting wire connected? black to black. That would cut your wattage enough to be very weak.

Red black is typically the battery in wires. Other colors out.

 

[Ykick]

Apparently the motor spins good, with good torque...

How do you arrive at that conclusion from this:

With the front wheel off the ground the wheel hardly moves at any speed ( can even be stopped by hand)...

 

[milly]

Thank you for your replys I shall try seeing output voltage and throttle voltage and motor conection tomorrow after a good nights sleep.
To answer some questions Both controllers state 36v on them think amps is 15 and I have tried with the speed limiter conected and disconected.
kind regards
Milly

 

[milly]

Power on wires to motor 36v OK Throttle wire 5v OK. Just conection to wheel to check now

 

[milly]

Hmmmm, I am confused now I tested throttle again and I had 4.8v on red+ to black- On signal wire from red+ to signal throttle shut 3.8 if I remember rightly and and nearly 0v with throttle open.
The conection into motor reads 36v
I cannot measure amps would that be useful if I could get a amp meter or not required
There may be a slight variation with the meter I was using being a cheap one and trying to hold both meter probs and hold throttle open with belly
Could I need a different throttle. I think the one I have is a hall effect one and not a potentiometer one.
regards
Milly

 

[e-beach]

If you were able to put a watt meter between the controller and the motor, that would give you an accurate measurement of the volts and amps the controller is delivering to the motor.

As for the Hall sensor throttle, 3.8v seems a little low, but Hall sensor throttles rarely delver much more then 4.5vdc.
They usually deliver around .8vdc at rest to 4.4vdc wide open throttle. It is possible to purchase and upgrade to a hall sensor that delivers more voltage, (allegro A1301 perhaps) but that should be for another day.

I am still wondering about your controller because the specs on the number you gave us clearly states 24v.

 

[milly]

Hi e beach,

I have checked both controllers and they say 36v on the label I would assume if 24v they would not give any outyput as they would be zapped with the extra voltage, but I am not sure of that assumption being no expert in these matters.

 

[e-beach]

I have checked both controllers and they say 36v on the label

any way to give us a picture of the model number of your controllers?

I would assume if 24v they would not give any outyput as they would be zapped with the extra voltage, but I am not sure of that assumption being no expert in these matters.

Not necessarily...most controllers are built with some extra "headroom" in their components for extra voltage. The only way to know for sure is to open the controller and look at the voltage ratings on the capacitors and power mosfets.

I just reread the whole thread to make sure I haven't missed something...let me make sure I understand what you have done

Ok, with the battery fully charged and the battery and the controller wired as per the instructions posted above, have you disconnected the motor from the controller, put the probes from your multi-meter into the blue and white connectors and pressed the throttle and got 36v to the blue and white connectors?

 

[milly]

In answer to the question yes I did get 36v from the motor wires ( blue and white ). I shall post pic when I get back from doing a bike build ( luckily not electric bike)
demo at our local peoples market in Lampeter.
Many thank for your time
Milly

 

[Tench]

Measure the throttle output voltage from the green signal wire to the black - wire, it should go from 1v to 4v as you open the throttle, your previous post says you measured from the signal to the + wire. this wont tell you if the throttle output is correct.

 

[milly]

Thank you Tench the voltage from signal wire to negative wire is 0.83v rising as the throttle is opened to 3.59.

Inclueded is pic of controller as requested earlier.

 

[e-beach]

OK, I am now very sure you have a 24v controller. I just compared your label with the specs of a Yiyun 24v 250w controller for sale on eBay. I think the 36v on your label is a misprint....

Check out these eBay specs and you will see everything on your label is the same but the 36v.
http://www.ebay.com/itm/24V-250w-Br...her_Vehicle_Parts&hash=item3a8990864b&vxp=mtr



I am beginning to believe that the over-voltage protection, what Yiyun calls "Short Voltage Protection" is what the problem is. (It is also why I wondered about you getting 36v from the blue and white wires.)

If you can separate a 12v cell from your battery pack and try to run the motor at 24v it might work provided the controller hasn't been burn out by the 36 volts that was hooked up to it.

Try to run it at 24 volts and see what happens.

 

[milly]

Thank you e beach it would appear that may well be the case. I am going to order a new controller and throttle and see what happens.
regards
Milly

 

[Paderolis]

Hello! I know this is my first post, but I wanted to share something. I have a eZip Trailz I bought a few months ago new, it had the 24 volt system. After reading about mods I wanted to upgrade it to a 36v system, this required a new throttle and controller as it is a 2013 model and can't be overvolted. The first controller and throttle I bought off of eBay from two different suppliers and when they arrived the throttle was a 4 pin and the controller was a 3 pin. Besides that the controller wires were way different from the bike wiring, and I didn't want to hack up the wiring on the bike!

I found a 36 volt throttle / controller Currie bundle pack online that was plug and play for my eZip minus the PAS, and it worked great for awhile! After some time I started having problems with the bike randomely becomeing unresponsive, and to make a long story a little shorter after some testing found the controller to be the problem. To confirm this I wired in the eBay controller and the bike worked normally without any hiccups, but I noticed it was a lot slower now! It felt more like it was on 24 volts again! I checked the specs on both 36V controllers and noticed the eBay controller had a max output of 15A and the Currie controller had a max output of 30A. When I wired the Currie controller back in, the bike ran quicker again but of course stopped after awhile because the controller was bad.

I have since bought another Currie controller and all is well! I typed ALL of that to ask this: Is it possible the max amperage rate on the controller is too low and that is why his bike is so slow at 36 volts? I am still learning about all of this, so I am genually curious! Thanks; and this is an awesome site!

 

[e-beach]

Hello! ....(snip).... Is it possible the max amperage rate on the controller is too low and that is why his bike is so slow at 36 volts? I am still learning about all of this, so I am genually curious! Thanks; and this is an awesome site!

That is a valid question, but the specs on the controller are a bit of a quandary. The Controller seems to be rated at 24volts by the manufacture, but has 36v on the label. Also on the label is what appears to be a "short circuit" rating (high voltage cutoff) of 31.5 volts which means if milly hooked up a 36 volt battery then the circuit or fuse in the controller would trip or blow. Only milly could tell us if it did. milly would have to open the controller and try to diagnosis it.

And yes, this controller is only 15amps, but the real problem IMO is that the controller is mis-labeled at 36v when is is really a 24v controller.

 

[Paderolis]

Hello! ....(snip).... Is it possible the max amperage rate on the controller is too low and that is why his bike is so slow at 36 volts? I am still learning about all of this, so I am genually curious! Thanks; and this is an awesome site!

That is a valid question, but the specs on the controller are a bit of a quandary. The Controller seems to be rated at 24volts by the manufacture, but has 36v on the label. Also on the label is what appears to be a "short circuit" rating (high voltage cutoff) of 31.5 volts which means if milly hooked up a 36 volt battery then the circuit or fuse in the controller would trip or blow. Only milly could tell us if it did. milly would have to open the controller and try to diagnosis it.

And yes, this controller is only 15amps, but the real problem IMO is that the controller is mis-labeled at 36v when is is really a 24v controller.



Okay, I understand; thanks! A mis-labeled controller will definitely cause some issues!
I hope the OP gets it figured out!

 

[Gregory]

The 31.5V on the label is the standard LVC for a 36V SLA battery. Its not over voltage.

As dogman alluded to , have you tried to run the motor straight off a 12V (no higher or it may spin too fast) battery to check the motor is OK?

 

[Ykick]

The 31.5V on the label is the standard LVC for a 36V SLA battery. Its not over voltage.

As dogman alluded to , have you tried to run the motor straight off a 12V (no higher or it may spin too fast) battery to check the motor is OK?

This, although full voltage wouldn't overspeed anything IMO. Just be careful to assure the wheel is off the ground.

 

[e-beach]

The 31.5V on the label is the standard LVC for a 36V SLA battery. Its not over voltage.

Opps... ...... but, the label is still inconsistent with the specs.
http://www.tncscooters.com/YK71/YK71.pdf

Unless the yiyun tech yk71 is marketed as a 24 volt and 36 volt controller. The same model number but two different voltages... .... http://www.cn-dcmotors.com/en/ProductShow.asp?id=220...



http://www.aliexpress.com/item/Yiyun-lb27-yk71-brush-controller-24v36v250w/1332244978.html.... :|

My thinking was that milly already tested the motor directly.

 

[Ykick]

wired 2 front hubs direct to battery pack and they both turn fast

OK, finally found it. My bad reading comprehension....