1st Build Q100--performance problems

[ammodave]

I just assembled my 1st bike using BMS Battery components (350W Q100 328rpm front drive, KU65 controller, 36v 10.4ah bottle battery) and it runs poorly. Max speed (loaded or unloaded) is about 12mph and the motor sounds like it's cycling or missing causing a speed limiting hesitation. Fully charged battery is about 42v by my meter. I've swapped around wire colors of the bullet connectors between the motor and the controller but the hesitation remains. I also swapped the wire colors at the five wire connector between the motor and the controller without any change. The PAS, cruise control and speed limiter connectors are not connected. Any suggestions what to try next? Does the Q100 normally run smoothly or is the cycling normal?

 

[-dg]

I just assembled my 1st bike using BMS Battery components (350W Q100 328rpm front drive, KU65 controller, 36v 10.4ah bottle battery) and it runs poorly. Max speed (loaded or unloaded) is about 12mph and the motor sounds like it's cycling or missing causing a speed limiting hesitation. Fully charged battery is about 42v by my meter. I've swapped around wire colors of the bullet connectors between the motor and the controller but the hesitation remains. I also swapped the wire colors at the five wire connector between the motor and the controller without any change. The PAS, cruise control and speed limiter connectors are not connected. Any suggestions what to try next? Does the Q100 normally run smoothly or is the cycling normal?

I don't have that motor, but that does not sound right at all. Things to try next:

- run it sensorless (5 pin connector unplugged), the KU65 will do this fine and testing this will tell you if the problem is just the Halls.

- try a different controller, or that controller on a different motor if you have either available.

- measure resistance between each pair of phase wires to check for shorts.

- spin the wheel forwards, it should be about like spinning a normal bike wheel

- spin the wheel backwards, there should be light drag and a quiet whir from the gears. Crunching noises not good.

 

[wesnewell]

No load speed should be 25.35mph in a 26" wheel. 26*3.14*328*60/12/5280. Wheel dia.XpiXrpmX60/12inches/5280feet per mile =mph

 

[ammodave]

I've tried it with the 5 pin sensor connector disconnected with no improvement. The wheel spins freely forward and only a slight resistance backward. Unfortunately, I only have the one controller so swapping it out is not an immediate option. I just did a quick check with an ohmmeter and found no shorts between any of the phase wires. Got any more ideas? I really like this set up if I can just get it to work properly. Can you recommend a US based retailer for a replacement controller? I realize virtually all the parts are made in China but I would prefer not to deal with overseas shipping.

 

[d8veh]

The most likely problem is the multi-pin connector down by the motor. Did you push it in until the line is level with the edge of the outer?

If you get a replacement controller, it has to be a high speed one.

The 328rpm motor doesn't run at all well in sensorless mode. Check again your hall sensor connector and check that there's no damage to the wire especially where it comes out of the motor. If the hall connection is faulty, the controller will switch to sensorless mode.

 

[ammodave]

I checked the multi-pin connector down on the fork and it's fully seated (with the arrows lined up). I removed the protective spring that protects the wire as it enters the hub. The outer insulation is undamaged. Do you think the KU65 controller is unsuitable for my application or just faulty. Can you suggest a US source for a replacement controller? Any easy way to troubleshoot this controller?

 

[chisixer6]

I have greenbikekit version of the q100, on 16"(305) rear drive wheel. I use their mini controller 36v Con61, with 12s LIPO, I match hall and phase wire color to color. It runs good, max speed with me about 20mph. this bike is a blast to ride compare to my bigger and faster ebikes, lightweight, heaviest thing would be the six 6s LIPOs.

 

[dogman dan]

The common problem is a poor connection on a wire. If you get a nicked phase wire, reducing it's wire size enough, you can get similar problems. If one phase can only get 2 amps, it's nearly like having one phase wire disconnected.

The other possibility is having the wrong wire order, but that is very hard to do in sensorless mode. Sensorless, it should run fine in one direction or the other.

I'd look real close at those phase wire plugs, and the insulation around the axle exit, etc.

 

[ammodave]

I've inspected the wire going into the hub and don't see any damage to the cable's outer insulation. All the wires at the 5 pin connector look good and the individual connectors are properly crimped. Is there any way to check the resistance of the phase wires to identify hidden damage inside the outer insulation of the large cable going into the axle? Can anyone recommend a better controller that's available in the US?

 

[wesnewell]

There are lots of places in the US that sells controllers. The problem is that they all come from China. So by buying from a US dealer, the markup is many times higher than buying direct in most cases.My 72V 1500W controller from China cost <$35 shipped a couple of years ago. Still under $50. From a US dealer you will pay many times that. Do a google search and you might find what you want. Examples.
http://www.ebay.com/itm/Brushless-Controller-36v-Sensorless-or-Sensor-With-Thumb-Throttle-/251123784270
http://www.aliexpress.com/wholesale?SearchText=36v+brushless+controller&catId=0&initiative_id=AS_20130413100728

 

[d8veh]

If you look on that motor connector, as well as the arrows, there's a line around the inner one. You have to push them together until the line lines up with the edge of the outer one.. If you didn't know that, it's easy to have them not pushed in far enough.

The KU65 controller is perfectly matched tothe Q100 motor. It has automatic configuration, which can detect phase angle, phase sequence and hall sensors IIUC.

 

[ammodave]

I checked the motor cable and it's fully seated down to the line but I still have a 12mph motor (unloaded). Is there any way to electrically test the controller to see if it's faulty? It seems warm to the touch after only 1-2min of operation. What's the advantage of add'l mosfets in a controller?

 

[d8veh]

It'll be a problem with your hall sensors or phase wires somewhere. Just to eliminate it, try pulling apart the phase wire bullet connectors, squeeze down the barrels and re-connect. Sometimes they feel tight, but it's the plastic shrouds making the resistance while the important bits are loose inside.

If that doesn't work, it may be worth taking a look inside the controller to check that all the hall wires are properly soldered.

Without a motor tester, you can check the halls with a meter with your probes pushed in the back of the connector while it's connected. Check in turn between the black and each of the blue, green and yellow wires. You have to rotate the wheel slowly backwards to see the halls pulsing on/off. Check that they all go on to the same voltage (about 4v) and off to0v. Give your meter time for the reading to stabilise between each switching. It helps to have someone holding the probes while you rotate the wheel.

 

[ammodave]

I double checked the fit of the bullet connectors and checked them with an ohmmeter to insure there is good continuity. When I checked the green, yellow, and blue wires I got a consistent minimum of .1v and a max of 5.02v on all three (using black as a ground). The voltage between black and red is a constant 4.36v. What kind of voltage should I be seeing on the bullet connectors? BMS Battery includes what they call a "meter" with the kit. It's basically an on/off switch, battery indicator, and 3 speed control. Can I "hot wire" around this and remove it as a possible culprit (i.e. it's stuck on low speed)? It's connected to black, red, blue, and green wires coming from the controller.

 

[d8veh]

To check the phase wires, you check continuity between each one and earth. There should be none. Then check continuity between each pair. There should be continuity.

Did you tighten the connectors like I suggested?

I can't see how the 3-speed switch would cause your problem, but it's logical to disconnect it until the problem is sorted.

 

[ammodave]

I tightened the bullet connectors and verified continuity with an ohmmeter. In the previous test you suggested, I got 0-5.2v on each wire turning the wheel backward. I checked for continuity as suggested in your latest post and got the following results: with power off there is no continuity between black and the blue/green/yellow wires, there is also no continuity between the blue, green, and yellow wires individually. I was leaning toward the 3 speed switch because the motor runs normally if you keep the speed below 12mph. Once it hits 12mph it starts to cycle on and off like a speed limiter is at work. The controller also has a speed limiter but I did not connect it. If I just disconnect the 3 speed switch, I am also disconnecting the on/off switch so I don't get any power to the motor or throttle. The connector for the 3 speed, on/off switch has 4 wires: blue, green, red, and black. Which of those wires would I need to jumper together to turn on the system?

 

[d8veh]

You short the blue to red to activate the controller without the panel, but I know that for some of these systems, the default situation is then that the throttle's off, and I've no idea what happens with PAS. It could be min or max or nothing because the green wire sends data to the controller. Hopefully yours will be OK because it doesn't have the throttle-off switch.

 

[chvidgov.bc.ca]

On my Ku65 controller, the three speed switch buttons on the "LED meter" doesn't actually do anything to the unloaded speed of the motor, spinning it in the air. I think the switch buttons work when PAS is used, otherwise not? I'm not using PAS

 

[ammodave]

Update: I shorted the red and blue wires together at the female "meter" connector coming from the controller leaving the remainder of the "meter" wires unconnected. Unloaded, the motor now spins to 34 mph; however, when I ride the bike it still tops out at about 12mph with the motor cycling off and on. Am I right in assuming the controller is limiting the wattage to the motor under load and 12mph is the best I can hope for with this particular (maybe defective) controller? Anyway to coax more watts out of the controller or do I need to just buy a higher wattage controller?

 

[Sunder]

Update: I shorted the red and blue wires together at the female "meter" connector coming from the controller leaving the remainder of the "meter" wires unconnected. Unloaded, the motor now spins to 34 mph; however, when I ride the bike it still tops out at about 12mph with the motor cycling off and on. Am I right in assuming the controller is limiting the wattage to the motor under load and 12mph is the best I can hope for with this particular (maybe defective) controller? Anyway to coax more watts out of the controller or do I need to just buy a higher wattage controller?

Still doesn't sound right to me. I have a Q100 running at 48V with a 20A controller. It tops at at about 22mph with 72kg of rider on it, but there is no feeling of the motor cycling on and off - it's perfectly smooth and constant - you simply run out of torque to go any faster.

Sorry I can't help you diagnose, I can only tell you what you describe doesn't sound like a limiter. It still sounds like something's broken.

 

[ammodave]

I agree; I've given up on my speed limiter theory. Something is apparently malfunctioning and I'd fix or replace it if I knew what the problem is. Controller?

 

[d8veh]

Does it run smoothly up to 12mph and then start cycling on/off, or is it a bit rough during acceleration?

 

[friendly1uk]

Have you checked the voltage on all 3 phases while running?
I'm no expert, but if I had to scratch around for an idea I would consider a phase is down. With less magnetic flux density, the motor finds less resistance to turning. Kinetic energy would carry the wheel around still and the timing would still work, although perhaps move a bit. You would loose a third of your power though, and it would run a bit rough, although somewhat rhythmically.

I seem to be hitting a few bases. Does this sound about right?

I would swap the controller if I was working blind, because there cheap.

 

[ammodave]

d8veh recommended I check the phase wires by measuring voltage while turning the wheel backwards. I did that and got a consistent fluctuation between about 0v and 5.2 v as the wheel turned backwards. It accelerates smoothly up to about 12mph and then the motor starts cycling (like it's being turned off and on) and maintains a constant 12mph when being ridden.

 

[d8veh]

It accelerates smoothly up to about 12mph and then the motor starts cycling (like it's being turned off and on) and maintains a constant 12mph when being ridden.

From memory, joining the white wires makes it behave like that. Look in the controller to see if there's a solder blob/whisker shorting out the two pads.