KT-LCD3 questions - help please.

[LIMI200]

Hello, I have recently switched my controller to a KT controller and a KT-LCD3 display with also a wuxing thumb throttle and it all works kinda well and I had a few questions regarding the settings.

I am not sure what is the correct P1 and P2 settings for me, I have a BFSWX02 48v 250w motor and if I am correct I only know it has 6 magnets in it, so if anyone please could help me know the correct parameters I would appreciate it. Currently it is set as P1 = 86 and P2 = 6, it seems like it kinda gets my speed correct but just to make sure I want to know I am safe.

Also I have my P5 set as 0 because I don't know the correct setting for my battery and when I look at the display VOL (at max battery) it says about 53 volts even though my battery is 48v only, weird?

Thank you.

 

[Deleted member 4366]

P5 ism a display damping factor for the voltage. All it does is slow down the response of the display. With a damping factor of zero, the display will show the voltage going up and down all the time, depending on how much power you use, i.e. It shows voltage sag. If you set it to a higher value, it smooths out the display so that the voltage can be used more like a fuel gauge. If you remember the old car fuel gauges that went up when you went round a left bend or when you were facing uphill, that will be P1=0. Modern ones just show you the fuel going down gradually until the warning light comes on. That's P5 = 14

P1 makes little difference in most cases, so leave it in the default value unless your motor gives severe vibration or stuttering at some speeds/powers. If you get that, come back and ask again.

P2=1 if you have a motor with an internal or external speed sensor. It affects the speed display. P2=0 will show the speed of the internal motor, which will go to zero when you're free-wheeling. It's OK for direct drive motors, where the motor is always rotating with the wheel.

Your battery should be 54.6v when hot off the charger and around 40v when empty. 48v is roughly the middle value.

 

[LIMI200]

P5 ism a display damping factor for the voltage. All it does is slow down the response of the display. With a damping factor of zero, the display will show the voltage going up and down all the time, depending on how much power you use, i.e. It shows voltage sag. If you set it to a higher value, it smooths out the display so that the voltage can be used more like a fuel gauge. If you remember the old car fuel gauges that went up when you went round a left bend or when you were facing uphill, that will be P1=0. Modern ones just show you the fuel going down gradually until the warning light comes on. That's P5 = 14

P1 makes little difference in most cases, so leave it in the default value unless your motor gives severe vibration or stuttering at some speeds/powers. If you get that, come back and ask again.

P2=1 if you have a motor with an internal or external speed sensor. It affects the speed display. P2=0 will show the speed of the internal motor, which will go to zero when you're free-wheeling. It's OK for direct drive motors, where the motor is always rotating with the wheel.

Your battery should be 54.6v when hot off the charger and around 40v when empty. 48v is roughly the middle value.

Thanks a lot for the replay Dave, really informative , also I had a question about the P2, at default it used to be 1 as you said but when I tried all numbers from 0-6, only 6 shows most accurate speed, so I don't know if it depends on the P1 or something, and no my motor doesn't have any weird vibrations or anything but I don't know if a wrong number will affect my motor in the long term.

Also, one more thing.
Why once I switched the controller and the throttle, when I full throttle and then release the throttle fully for about a second and then full throttle again it has a really annoying delay, sometimes ranging between 1 to 2 seconds.

 

[Deleted member 4366]

P2 is the number of magnets in the speed sensor, which is normally one if you have either a speed sensor in the hub or the wheel. If the value 6 gives accurate speed, then it's using a motor hall sensor to get the speed intstead of a speed sensor. which motor do you have?

The throttle one is unusual. I've not heard of that with a KT controller before. I can't think of any settings that affect the throttle, so maybe it's a thottle problem, like a faulty connector.

 

[awol]

Thanks a lot for the replay Dave, really informative , also I had a question about the P2, at default it used to be 1 as you said but when I tried all numbers from 0-6, only 6 shows most accurate speed, so I don't know if it depends on the P1 or something, and no my motor doesn't have any weird vibrations or anything but I don't know if a wrong number will affect my motor in the long term.

Also, one more thing.
Why once I switched the controller and the throttle, when I full throttle and then release the throttle fully for about a second and then full throttle again it has a really annoying delay, sometimes ranging between 1 to 2 seconds.

I have been messing about with setting P1 recently as my speed was showing incorrect on a new LCD3. I made sure P2 was correct to the number of speed sensor magnets then used a GPS speedo to give my speed on my mobile phone. Then increased P1 until my speed matched.
The default P1 was 87 and I ended up changing it to about 202 I think which matches my calculation of 16magnets x 12.6 reduction ratio.

 

[Wheel-E]

Why once I switched the controller and the throttle, when I full throttle and then release the throttle fully for about a second and then full throttle again it has a really annoying delay, sometimes ranging between 1 to 2 seconds.

My Kunteng controller (with KT-LCD1) does that. I need to do a bit more testing to understand exactly what's going on but the throttle is delayed by a second or so only if the wheel is moving. It's bloody annoying.

 

[Nealh]

My Bafang cst I use P1/ 84 to match gps speed and p2/0 for real worlD mph and freewheeling mph, using P2/6 I get 0 mph freewheeling.

 

[LIMI200]

P2 is the number of magnets in the speed sensor, which is normally one if you have either a speed sensor in the hub or the wheel. If the value 6 gives accurate speed, then it's using a motor hall sensor to get the speed intstead of a speed sensor. which motor do you have?

The throttle one is unusual. I've not heard of that with a KT controller before. I can't think of any settings that affect the throttle, so maybe it's a thottle problem, like a faulty connector.

Hey again, my motor is BFSWX02 48v 250w, I also did some research and found out that it has 6 magnets speed sensor inside, so I guess P2=6 is correct?

It also seems by the replay of Wheel-E that he has the same issue, I will look into it more.

 

[Wheel-E]

Just had a quick test. It seems the delay is proportionate to the speed.

Throttle actuation when wheel still = Instant response.
Wheel spinning slowly = Small hesitation before throttle response.
Wheel spinning at full speed (27.5MPH) = approximately 1.5 seconds until I hear and feel the motor kick in.

If I use the throttle, keep it pressed a bit, then increase throttle the response is instantaneous. It's only when you relase the throttle an re-engage that there seems to be this delay.

Controller is KT36ZWSRM-GP05

 

[awol]

Just had a quick test. It seems the delay is proportionate to the speed.

Throttle actuation when wheel still = Instant response.
Wheel spinning slowly = Small hesitation before throttle response.
Wheel spinning at full speed (27.5MPH) = approximately 1.5 seconds until I hear and feel the motor kick in.

If I use the throttle, keep it pressed a bit, then increase throttle the response is instantaneous. It's only when you relase the throttle an re-engage that there seems to be this delay.

Controller is KT36ZWSRM-GP05

I'm sure I had a similar problem before I started adjusting setting P1.
Out of interest maybe check the LCD speed on the road against a GPS speedo app on a mobile.

 

[Deleted member 4366]

Hey again, my motor is BFSWX02 48v 250w, I also did some research and found out that it has 6 magnets speed sensor inside, so I guess P2=6 is correct?

It also seems by the replay of Wheel-E that he has the same issue, I will look into it more.

It doesn't have 6 magnets. There's a lot more than that - closer to 18, I'd say. Reduction ratio is around 5, so the ideal P1 must be in the region of 90.

 

[LIMI200]

It doesn't have 6 magnets. There's a lot more than that - closer to 18, I'd say. Reduction ratio is around 5, so the ideal P1 must be in the region of 90.

Yea when I meant 6 magnets I meant 6 magnets in the speed sensor, I know it sounds weird since there is usually 1. And yea I guess there is about 18 to 20 magnets in the motor itself.
Thanks again

 

[LIMI200]

Just had a quick test. It seems the delay is proportionate to the speed.

Throttle actuation when wheel still = Instant response.
Wheel spinning slowly = Small hesitation before throttle response.
Wheel spinning at full speed (27.5MPH) = approximately 1.5 seconds until I hear and feel the motor kick in.

If I use the throttle, keep it pressed a bit, then increase throttle the response is instantaneous. It's only when you relase the throttle an re-engage that there seems to be this delay.

Controller is KT36ZWSRM-GP05

Wow, thats exactly what I'm dealing with, I showed the seller from aliexpress and he said:
"This is the future of the KT controller. To prevent big current at the start."

Does that sound legitimate, anyone else has that problem? @d8veh

 

[Deleted member 4366]

It would help if you tell us which motor you have and whether it's sensorless or not, and whether your controller is sensorless.

 

[LIMI200]

It would help if you tell us which motor you have and whether it's sensorless or not, and whether your controller is sensorless.

Motor: 8Fun BFSWX02 48V250W(13) - It is hall sensored & it has 6 magnets speed sensor inside.
Controller: KT48ZWSRT-LCD-C&D 48V350W - It is compatible for hall sensored motors. On Aliexpress: https://goo.gl/cezKPV

 

[Deleted member 4366]

I've never seen throttle delays in a sensor controller, though they're common in sensorless ones because the controller needs time to figure out the position of the motor, which it gets very quickly from the halls.

 

[Wheel-E]

I've never seen throttle delays in a sensor controller, though they're common in sensorless ones because the controller needs time to figure out the position of the motor, which it gets very quickly from the halls.

It's really noticeable when you slow at a roundabout (brakes cutting the motor), for example, see it's clear and then engage the throttle and then a big wait before you feel the power.
I'm wondering if that when throttle is engaged, the power is ramped up gradually which accounts for the apparent delay when going faster.

 

[Deleted member 4366]

Throttle ramps are pretty normal.

 

[Nealh]

No delay with my 2 sensored KT's and even my Luishi unsensored has no delay.