Help | KT Display settings

[eliyad888]

Hello everyone, recently my ebike motor went bad so I used the opportunity and bought from a shop nearby me a new 1500w fat bike (4in wheel) motor and after that I bought also a new KT 1000w controller and lcd8H display but the problem is that I don't know what P and C settings I should put in my display because I don't know if there is any connection between but the speed on the display isn't right and sometimes it even says zero.
It would be awesome if anyone could help me thanks a lot

 

[amberwolf]

What conditions cause it to show zero?

If it's random, there's probably a broken wire or poor connection between the sensor and the controller. (if it uses the motor halls to read speed from, and this is the case, it will also cause wierd motor behavior).

If it's not random, there will be a pattern, and knowing that pattern will help figure out why it isn't always working. (for instance, geared hubmotors without a wheelspeed sensor inside the cover (separate speedo wire) will only read speed while the motor is running fast enough to drive the wheel forward--otherwise there is no reading or low reading).

 

[docw009]

You didn't say, but the motor must run, and the LCD8H shows a speed when the throttle or PAS is working? It doesn't show speed when the motor is coasting?

Does your bike uses an external speed sensor? Did you have speed showing on the original bike display? Is the new motor a geared motor? If it is, it will spin freely in forward direction, but you hear/feel gears turn in reverse direction).

Start with P1 = 100 for a geared motor, especially if it's a fat tire model. The bafang motors used in the original Sondors bikes used 100. It has a real derivation, and is equal to the number oif motor magnets times the gear ratio of the motor. Many inexpensive fat tire motors are copies of those original bafangs and end up having the same P1..

The controller uses P1 to calculate the bike speed when there is no speed sensor. Some users will adjust P1 til the LCD shows the right speed, Make sure you have the right wheel diameter entered into the LCD display or the speed will be calculated wrong, The KT controller knows the motor rpm since it is spinning the motor. It uses that plus the wheel diameter to calculate speed when the motor turns.

When the motor coasts, the controller has to use a speed sensor to determine wheel speed. This is where the P2 parameter is used. P2 is either 6 or 1 for a geared motor, Use 6 for most bafangs, Other motors are P2 =1. or you use P2 =1 when there is an external speed sensor. When P2 = 0. you're telling the controller that there is no speed sensor. If you have a non zero value of P2, and you get no speed, then you may not have a speed sensor in the wheel.

If your motor used a 9 pin round plug and has a speed sensor, it's automatically located in the plug, and the KT controller picks it up. If the motor instead uses three thick wires with bullets and a 2x3 rectangular plug, the speed sensor would be the white wires in the latter plug, If you have no speed sensor in the motor, then you have to use an external wheel sensor.

 

[eliyad888]

What conditions cause it to show zero?

If it's random, there's probably a broken wire or poor connection between the sensor and the controller. (if it uses the motor halls to read speed from, and this is the case, it will also cause wierd motor behavior).

If it's not random, there will be a pattern, and knowing that pattern will help figure out why it isn't always working. (for instance, geared hubmotors without a wheelspeed sensor inside the cover (separate speedo wire) will only read speed while the motor is running fast enough to drive the wheel forward--otherwise there is no reading or low reading).

You didn't say, but the motor must run, and the LCD8H shows a speed when the throttle or PAS is working? It doesn't show speed when the motor is coasting?

Does your bike uses an external speed sensor? Did you have speed showing on the original bike display? Is the new motor a geared motor? If it is, it will spin freely in forward direction, but you hear/feel gears turn in reverse direction).

Start with P1 = 100 for a geared motor, especially if it's a fat tire model. The bafang motors used in the original Sondors bikes used 100. It has a real derivation, and is equal to the number oif motor magnets times the gear ratio of the motor. Many inexpensive fat tire motors are copies of those original bafangs and end up having the same P1..

The controller uses P1 to calculate the bike speed when there is no speed sensor. Some users will adjust P1 til the LCD shows the right speed, Make sure you have the right wheel diameter entered into the LCD display or the speed will be calculated wrong, The KT controller knows the motor rpm since it is spinning the motor. It uses that plus the wheel diameter to calculate speed when the motor turns.

When the motor coasts, the controller has to use a speed sensor to determine wheel speed. This is where the P2 parameter is used. P2 is either 6 or 1 for a geared motor, Use 6 for most bafangs, Other motors are P2 =1. or you use P2 =1 when there is an external speed sensor. When P2 = 0. you're telling the controller that there is no speed sensor. If you have a non zero value of P2, and you get no speed, then you may not have a speed sensor in the wheel.

If your motor used a 9 pin round plug and has a speed sensor, it's automatically located in the plug, and the KT controller picks it up. If the motor instead uses three thick wires with bullets and a 2x3 rectangular plug, the speed sensor would be the white wires in the latter plug, If you have no speed sensor in the motor, then you have to use an external wheel sensor.

Thanks a lot for the help guys.
So my new motor is using 2x3 rectangular plug and I checked a few tines and it's connected very well. The display shows zero and after a while while I am causing (at the same speed) it shows the speed and not the correct speed (it shows lower number).
The shop that I bought the motor from said that this motor isn't geared.

 

[docw009]

If not geared, then no white wire in the 2x3 plug. Set P2=0 and start with P1=20. Adjust it up til speed matches. If you still get no speed on coasting, the seller may be wrong. I think a direct drive fat tire motor is going to be somewhat weak for climbing.

You can always buy a wheel sensor and hook it up with P2-1.

 

[eliyad888]

If not geared, then no white wire in the 2x3 plug. Set P2=0 and start with P1=20. Adjust it up til speed matches. If you still get no speed on coasting, the seller may be wrong. I think a direct drive fat tire motor is going to be somewhat weak for climbing.

You can always buy a wheel sensor and hook it up with P2-1.

It worked, thank you very much for the help and just out of curiosity what's the white cable and why does it have to be not plugged?