Speed Issue On New Build

[AC9999]

I just joined but have been a long time reader. Thank you to all the well know members who seem to give the best advice in almost every post I happen to be reading. I've learned a lot. Ok now the details. My first build.
2005 Specialized Hardrock Sport
48v 1000w Mxus V1 motor with matching KT controller (15a 30a max) and KT-LCD1 display all from Changzhou Hua Yu Xin Feng Motor Co., Ltd.
48v 20ah Li-NiCoMn 18650 Triangle pack from Shenzhen Lamye Technology Co., Ltd. (specs of pack below)
GT Power 130a Wattmeter

The problem I'm having is not getting close to 20mph unless also peddling with the wind at my back on flat ground. Then I get 20-22mph. I myself am 225 plus the bike. I know it's not a V3 with 72v but shouldn't I be able to get close to 30? This is what all my research on here told me. I thought I did good. (I know I should have started with a weak setup and then been schooled on how to do it right but I did a lot of reading and skipped that part.) The speed limiter is maxed out and all my P settings are correct besides P5. Some say at 48v it should be 15 others say LVC + P5 / 3.77 which is around 22. Confirmation on this would be appreciated.

I originally thought I got ripped off on my battery because a low ah 36v pack would explain the lack of speed and torque. (I know don't buy from China buy from well known proven members who will support the sale. Just wasn't in budget. I did get a good deal if actually legit) But fully charged it does read 54v and will run quite a while. I just got done with a 15+ mile ride using mainly the throttle and I'm only down to 46v. Slow speed though, average 15-17mph. The pack is supposed to be BYD cells but it had a manufacturers sticker from Shenzhen AODA New Energy Technology CO., LTD in the box. Lamye claims they use them to ship because they can't. A little fishy. So are these BYD, AODA or just cheap Chinese cells? ? I had them send a single extra cell to examine. Pic below of cell and of claimed specs of pack. If the pack is legit I need to retract my dispute with them through Alibaba.

My wattmeter may be faulty or the problems with it may be a result of the underlying issue(s). It only shows the top 2 readings until voltage drops below 46. Then the bottom will cycle the readings properly. It won't show anything with battery fully charged until motor starts and voltage drops a bit. Pics are below of readings from an in progress ride of 15-17mph. I believe motor is Ok but have not checked internal wires yet.

So...Are those numbers correct? Can someone explain what I should look for value wise? Is there not enough power being pulled? Bad controller? What could be my issue?
An advance thank you to all that chime in and give me some insight into this issue. Here are the images.

 

[d8veh]

Despite their specifications, those wattmeters don't work very well with a 48v battery. If you search far enough back through the forums, there's a mod you can do somewhere to improve it. That's nothing to do with your problem.

P5 is a damping coefficient for the battery display in the LCD. It has no affect on controller or motor function.

KT controllers are normally set to current control, so power is limited on any level except 5 with PAS, but unlimited for throttle.

Your problem is that the controller's only giving 7.4 amps. The question is why? Are you using a throttle? Did you try it with PAS@

 

[AC9999]

Yes I've tried throttle and pas. Throttle gives me 15-17mph and pas on 5 with some hard peddling and wind at my back will top out at 22mph.
So I guess the question is what's the issue with the low amps. At least now I know where the problem could be. Possible solutions?
I know the P5 setting won't change anything but the correct one should at least properly gauge battery and LVC. What should that be set at?
Talking about remote shunt mod on the wattmeter?

 

[spinningmagnets]

Amps being limited by not setting up a jumper wire correctly will affect acceleration. I haven't used one of those controllers before, so I'm not familiar with it.

However, top speed is controlled by

1) System voltage
2) Motor Kv
3) Tire outer-diameter

I just thought, there might be a top speed limiting function on that controller (I don't know for sure). If there is, it is a way to have a street-legal speed on one setting, and unrestricted top speed on another setting.

 

[AC9999]

Everything is set correctly as far as max speed. (Although it reads 72kph even though its set to imperial, so 44mph) The KT-LCD1 does have the same style . functions as the LCD3 just not the higher advanced settings past the P1-5, no C settings accessible.

Voltage is 48v on a 20ah Li-NiCoMn pack. After a 15+ mile ride mainly throttle max speed at 17mph I had 46v left on battery. Even at full charge 54v I get same performance.

.....The MXUS "1000W" motor has a stator width of 28mm. The common winding option for this motor is a 9 x 7T (9 strands of copper in parallel x 7 turns around the stator tooth), and the resulting Kv is about 8.5 RPM per volt......

Tire size is 26. It is set correctly in the LCD1.

The complete system is plug and play all from the manufacturers of the Mxus motors. One complete kit. There are no additional wires to jump. If it was all solder and heatshrink matching up wires from different components and I missed something or miswired something then at least there would be a simple way to troubleshoot because that would likely be the reason.

Could it just be the amps on the battery pack are so low? No one ever chimed in on the image of the cell yet. I've been waiting for an email from rafeh1 at Calibike on a confirmation on the cell image since his packs are AODA cells. Well i guess the Amps would have more to do with torque and distance and the volts would control the speed. I'm stumped.

I know some of these troubleshooting questions from you guys seems like "I have no power. ""Did you turn on the power on button?"" " are needed to check the simple things first. I do get it. I am new. I could have missed anything. We all started at the beginning at some point. I appreciate the time you all take to help us all out. Thank you

 

[skeetab5780]

You could have just bought a really slow wind motor. I see them a lot on Ebay. My first kit was the original 48v 1000w Golden Motor kit off Ebay. It came with a 30a controller and in a 26" wheel with the same battery you have I could get 32mph at max draw/speed/full charged

I would start by swapping the controller out to get more amps to the motor. It is cheap and easy. Then if its still slow id sell your motor.

 

[AC9999]

That's just it though. It is a reliable motor from Mxus strait from the factory. Not ebay or amazon. The setup is a proven reliable system that yes like your first kit should hit those speed limits. The controller is a 30a max controller. Acceptable for this "higher end" well know name brand non hot rodded setup. I am trouble shooting with both the motor and battery suppliers to try and find out where the Amp limiting block is as well.

 

[AC9999]

Ok let's try this. How can I, following the path of electricity through all the components, measure input and output with a multimeter to see where the loss or block of power is. We all think it's a loss of Amps reaching the motor correct? What should be the measurements coming from battery going into the controller and then from controller to motor on a full load. I know I'll have to rig up a jumper setup between plugs to connect flow of other wires and put multimeter in line to read amps. It would be helpful to know the configuration of the KT controller plugs. Anyone have that?

 

[d8veh]

There's no problem with your battery or cells. If there were, the display would switch off when you drew too much current. Nothing can block the current. Instead, the controller allows it by the time interval that it opens the MOSFETS (PWM).

Maybe the controller is faulty. It measures the current though the shunt/s. Some controllers use solid state shunts, but most use a hoop of shunt wire. Maybe the shunt isn't soldered properly, so its resistance has increased, which would make the controller think that the current is higher than it is.

P5 is only a damping factor, like I already said, it stops the battery meter going up and down with the power and keeps it steady, a bit like car fuel gauges. The old ones used to go up and down when you went round a corner or up a hill. Now they have damping, so it stays steady. It doesn't matter what you set P5 to. You hardly see a difference unless you set it to zero.

One thing to look out for: can you make the current go way above 7.4A by going slowly up hill? When you open the throttle, does the current go right up and then settle back down to 7.4A , or does it never go over?

Something I don't understand. In your first most, you mentioned 15A and 30A. What's that all about?

 

[AC9999]

I understand about P5. It's a visual thing on battery bars. Got it.
Picture of controller below. Explains what I meant for 15a and 30a max.
I'm in South Florida. Not too many hills around. But when I try accelerating through some thick grass at a slight incline and I feel the motor struggling before adding some peddle power there is not much of an increase as far as I can remember I've not seen it go past 8a. I will double check this after I repair a solder point on wires and ride it enough to drain some power to actually see the lower row of values on the meter. What a PITA! Will the watt's up perform better with the 48v? At almost a $50 increase in price I'd imagine it would. I'll eventually move up to a CA on next build.

So it's probably a faulty controller. I will have to fight with them to get a replacement. Any way of testing it with multimeter to show proof that it's defective?

You see controller below. They do have a beefier controller made for their V3 3000w motor. It's a 60a max. Would that be compatible? Still run off a 48v? Might as well upgrade now so if I move up in voltage some day I already have a controller that will handle it and it's plug and play without getting one from Lyen and rewiring everything. If not I'll just get a replacement of the same model and upgrade on next build.
Thanks so much

 

[skeetab5780]

It doesn't matter where the motor came from...Most manufacturers make different windings(kv rating) there are slow wind hubs that only do like 15-17mph on 48v 26" wheel.

But that controller looks a little underpowered to me. Its probably 15a max.

 

[AC9999]

Do you see the image of the controller above? Clearly states 30a max. I have internal shots of the board as well if I need to post them. There is a quote above from teslanv speaking about this particular motor. He knows the Mxus brand very well. This motor is capable of speeds around 30mph with a 48v battery. It can also be pushed quite far past that with the proper cooling and increased voltage and matching controller. I'm not looking for all that or to sell the motor to try and fix the problem. I'm trying to troubleshoot the underlying issue of this capable kit not performing properly.
d8veh believes it is a faulty controller. I am in agreement because that would make sense. Once I can get a replacement I will know for sure.
If it was a bad decision on my part for buying an under powered setup it would beyond make sense immediately to me as being the reason for the low speed.

 

[wesnewell]

It would have to be ~5Kv motor to go that slow on 45V. I don't think they make one slower than 6Kv.. However if it is a slow wind motor it won't take a lot of amps to max out. When modifying my shunt I put the bike against the wall for max load and then hit the throttle to see how many amps it would pull. Not real accurate, but enough. If you do this and can't draw a lot more amps, then there's a controller problem. My controller cut out when it reached max amps. Don't hold it long there are you may burn the controller or motor up. A few seconds at most. This should give more insight into the problem. Or just hold the brake to see if you can get more amps. You need to be on the bike or the wheel might spin. Most 48V 1000W kits are 9Kv higher motors. Mine is ~9.75Kv. 870 rpm at 90V.

 

[amberwolf]

If you're willing to open up the controller, at least take off the end cap away from the wiring exit, youc an check to see if all the shunts are correnctly isntalled. IIf they left one out, asssuming two normally, a 15A controller would become a 7A. Or if it is not soldered in at one end.

 

[AC9999]

Maybe the controller is faulty. It measures the current though the shunt/s. Some controllers use solid state shunts, but most use a hoop of shunt wire. Maybe the shunt isn't soldered properly, so its resistance has increased, which would make the controller think that the current is higher than it is.....
...One thing to look out for: can you make the current go way above 7.4A by going slowly up hill? When you open the throttle, does the current go right up and then settle back down to 7.4A , or does it never go over?

....When modifying my shunt I put the bike against the wall for max load and then hit the throttle to see how many amps it would pull. Not real accurate, but enough. If you do this and can't draw a lot more amps, then there's a controller problem. My controller cut out when it reached max amps. Don't hold it long there are you may burn the controller or motor up. A few seconds at most. ....

If you're willing to open up the controller, at least take off the end cap away from the wiring exit, youc an check to see if all the shunts are correnctly isntalled. IIf they left one out, asssuming two normally, a 15A controller would become a 7A. Or if it is not soldered in at one end.

Ok with the bike against the wall and riding through some taller grass with motor struggling a bit it went to a little over 9A. What does this mean?

I took pictures of the inside of the controller as soon as I got it. I knew I'd have to see it for a date or board number or something. If I need other angles or to test something in it let me know. I really want to get this thing up to speed.

 

[d8veh]

The shunts are those two copper coloured wire hoops at the front. Check that they're properly soldered. I can't see clearly in the photo, but the front left looks a bit suspect.

If your controller or your motor was limiting the speed, you would only be using enough current to maintain that speed, which would be about 7 amps, but the controller should allow, and the motor should take, the maximum when you open up the throttle from a standstill, so I would expect to see on your wattmeter something like 25 amps as you pull away, gradually decreasing to 7 amps as you reach the slow top speed.

If it's the controller limiting the current, your wattmeter would show a more or less constant current of 7.4 amps while you accelerate.

We need to determine which of the two it is.

 

[AC9999]

Then I'd definitely have to say defective controller. I've never seen it hit 10A let alone 25A. Even with the above tests it only hit 9A.
Any insight to the beefier controller I asked about? I think they also have a 35A too. If the 60A is too much I'll see if I can get em to upgrade me to the 35A for my troubles.

Any help from anyone on the battery pack and cell I was asking about. Need to continue the fight... I mean discussion with my Chinese battery seller in a few hours about not believing a word they say. Any and all opinions on the type cell would be welcome. I already have my thoughts I just want to here from a few other to back up what I think.

Thanks for all your help.

 

[wesnewell]

The solder joints look suspect to me. Hard to tell for sure without looking at the bottom of board, but I'd guess both the ones on the left are cold, and suspect the same on the right. I'd take a good hot iron to them until you get a good solder connection.
https://www.google.com/search?q=good+solder+connection+photo&espv=2&biw=1740&bih=1003&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwj23PHouMfMAhXK7iYKHRzaDTAQsAQIGw&dpr=0.9

 

[skeetab5780]

Wait but the controller says its 30amps... It must be 30amps even though it draws 7... Haha

 

[AC9999]

Wait but the controller says its 30amps... It must be 30amps even though it draws 7... Haha

Really? Because nothing ever breaks and gets damaged or is defective right? I'm not saying i believe everything written on a sticker coming from china but hey everything we ride pretty much comes from there. You gotta sometimes take things at there word until you can prove otherwise. That means troubleshooting through all the possibilities until your left with the truth. It's a new build with new parts and I'm a new builder. Cut me some slack. I get a replacement sent and it works I know it was bad. I try re-soldering the shunts, which I'm doing shortly, and that works then I know that was the problem. None of that works then I know it's a bogus controller. I hate to see how you'd help someone with no clue and understanding of any of this. Everybody else has been so helpful with real direction on actually testing and fixing the issue. Your advice is go buy more gear and spend more money. I like working through problems and learning and gaining knowledge. Not take the easy way out first sign of an issue and say "Oh I guess it don't work. I'll just buy more stuff and replace what might be wrong without really knowing if it is or not."

 

[wineboyrider]

Might be a good time to look up solder shunt mods and beef up that controller a little bit. 8)

 

[aroundqube]

How does LCD-1 work with the controller? Are there levels of assist that have to be set on the LCD ? What if he unplugged the LCD ? Would the controller default to a low assist level ? Does it get the different levels of assist by working with the 2 shunts ? The reason I ask is that the solder at the shunts look to pool together. Can he unplug the LCD and jump some wires to the controller to command full assist ?

 

[amberwolf]

The reason I ask is that the solder at the shunts look to pool together.

Shunts are always paralleled directly like that.

The only problem with them might be if they are not fully connected to each other (and the board); their resistance would be higher and the controller would *think* current was higher, when it isn't.

That's how shunt mods work to give *more* current than actual, by reducing shunt resistance so the controller *thinks* current is *lower* than actual.

 

[AC9999]

How does LCD-1 work with the controller? Are there levels of assist that have to be set on the LCD ? What if he unplugged the LCD ? Would the controller default to a low assist level ? Does it get the different levels of assist by working with the 2 shunts ? The reason I ask is that the solder at the shunts look to pool together. Can he unplug the LCD and jump some wires to the controller to command full assist ?

There are 5 PAS levels. Well 6 in you include 0 which is no assist. There is a difference between them so that is functioning correctly.

Ok I did some soldering on the shunts after squeezing them together a little. I also beefed up the long run in back and the one behind the fets. They were not really done well. Look better? I also included a shot of one of the fets. 80NF70 specs say 68V and 98A.

Now to put it all back together and see if it helped. I'll let you know after a bit.

 

[AC9999]

Well that didn't work. It was running at the same speed and acceleration but couldn't get a read on the amps yet due to the crappy GT wattmeter not being able to function at higher volts. I ordered the watt' s up yesterday. Hoping that'll be better. Anyway after a few minutes of riding it seams something shorted out.
The motor will slightly lunge forward and stop. No rotation just a weak lunge when I press the throttle. Now what? I'm dead in the water. Did I fry my motor?
Did the shunt mod and beefing up those long runs work but the controller really was damaged and couldn't take it?
Help.