Kt Controllers Compatibility

[AccountMember]

I have a kit that uses an older Kunteng controller

When i adjust the parameters using LCD3 it seems to have no effect on the current when measured separately with a watt meter. '

I changed the C11 parameter to LCD1/LCD2 mode but it hasn't helped like it should have.

Anyone have any ideas what i can do apart from buying the LCD1 which is my last option as i prefer the LCD3 but obviously not if i can't get it to work

 

[d8veh]

What makes you think that you have a Kunteng controller?

Which Cyclotricity kit do you have?

When you switch the LCD on, what do you see on the display?

 

[rote]

Hi d8veh,
I have a similar issue (you might recall my first ES post re: wiring a CA to a non-CA controller). I have a generic Chinese 48v 1000w ebike kit picked up off ebay. In the ad, it showed it with a KT48ZWS-ZC12, but actually arrived with a "DC MOTO" 48v 26a (black in color) controller. It also came with a SW-900 LCD display with 5pin connector (which looks pretty similar to the KT-LCD2 display). My KT-LCD3 arrived yesterday as I wanted to also view voltage and temps.

When I first plugged it in, the battery indicator showed nothing even though the battery was charged to 52v. After changing the P5 setting to 00, the battery indicator went to full. Good. Everything seems to display properly (haven't ridden it yet) like the voltage and temp, however, the speedo doesn't work at all. (I've been lifting the rear wheel and throttling). I have the advance LCD3 manual, have pored over this site and others, trying every possible P and C settings, with no success. Do you think it's a setting, or might the speed sensor/wire be defective? (my motor is BLDC DD with Hall sensors. Prior LCD display worked fine). Any help would be appreciated!

 

[d8veh]

The LCDs are very sophisticated. They have a substantial amount of processing power, which they use to share information with the controller. Both the LCD and the controller have software in their CPUs. What that software does is decided by the programmer. The chance of advanced settings from a non-paired LCD working with any controller wouldn't be high. i.e. Kunteng LCDs work with Kunteng Controllers, but even then, they can have different software versions that doesn't match exactly.

Some Kunteng controllers have software in them that allows small changes to current and LVC, but there's nothing to say that the software in your black controller allows that.

The easiest way to change the maximum current in a controller is to shave or crimp the shunt to reduce the current, and add solder to increase it. Note that the LCD won't show any change because it will be measuring the current incorrectly. You need an external wattmeter to show the difference.

Many controllers are now using solid state SMD shunts - sometimes three separate ones, with one on each phase. For these, you need to change the resistance value by replacing them or by soldering another on top according to the formula 1/R_new=1/R_old + 1/R_added.

 

[rote]

Thanks for the reply. Too bad it's likely a software issue - that's what I was afraid of. Fwiw, I went for a ride yesterday eve. It does turn on the controller; it shows the battery indicator; it shows the real-time voltage; it shows the outside temp. It did not display the speed/mph; trip/odometer; real-time watts; or motor temp (well, it was just stuck at 32F).

I really like the real-time voltage, but speedometer and odometer are also important to me. Looks like I can't have it all. Thanks again though for your analysis and help.

 

[d8veh]

The LCD is powered by positive and ground wires that are directly from the battery- even though they come out of the controller. That means that the LCD can be switched on to display the battery voltage that it gets from those wires and temperature that it gets from its internal temp sensor (nothing to do with motor). You can get all that by just connecting the two wires without going anywhere near a controller.

When you switch it on, it also connects the battery positive to a return wire that powers the controller. Everything else is done by exchanging information, which requires software compatibility and equivalent data protocols.

When the controller is switched on by the LCD, the throttle normally works, though often not with full power, and you can get other problems, like the controller entering sleep mode after a few minutes.

 

[rote]

Good information, thanks. Prior to getting the LCD3, I picked up one of those generic Turnigy watt meters. I guess they're not as well made as from a few years ago because when my battery is ~>48v, the screen just flickers. Apparently it can't handle the voltage even though it's advertised as 60v. So unmounted it (didn't do the shunt mod because i presently don't have that ability) and trusted the LCD3 would work. Alas, may just have to do the CA controller mod one of these days.

 

[rote]

Hi d8veh, or anyone else who can help. So, determined to use the KT-LCD3 display, I went ahead and picked up a KT controller ( this one - http://www.aliexpress.com/item/36V-350W-bicycle-Brushless-DC-Sine-Wave-Controller-36V-250W-Electric-Bike-48V-250W-350W-ebike/32369862627.html?spm=2114.10010108.1000014.28.ZLoEzX&scm=1007.13338.33346.0&pvid=5fe4ec3a-74f6-4b3b-9ba9-7deaf71929d6&tpp=1 ). With my DC MOTO controller hooked up to the KT-LCD3, as previously mentioned, I could turn on the controller and see the voltage but nothing else worked/displayed properly. But at least the throttle worked fine and I could ride it.

Now with the KT controller, the throttle does not work at all. I have set both P4 and C4 to 0 for zero start ability. (The speedo works now though because when I spin the wheel by hand it displays the speed.) The main wire differences I can see are: i) the KT throttle wires are R-B-Bl while the throttle wires are R-B-G; ii) the KT has 6 Hall wires while my hub motor has 5 wires (KT's sixth wire is white); iii) the KT PAS wires are R-B-Y while the PAS wires are R-W-B. The KT controller also has a speed sensor, cruise, and some lighting wires, although I don't think these would affect the throttle?

I even did the Grin Tech throttle test with my multimeter and it passed those tests. I have not tried changing any color combos for the phase or Hall wires because it seems you should at least get some wheel movement or noise at any combo - but mine is completely dead/silent. So I get a KT controller and still can't the LCD3 fully functioning. I'm at wit's end. Do you know what the problem might be? Thanks!

 

[d8veh]

The throttle doesn't work on level zero, so make sure you select anything from 1 to 5.

If that's not it, while everything is connected and switched on, measure the voltage between the throttle signal wire and the black while you twist the throttle to check that it goes from approximately 2v to 4v.

 

[rote]

With my previous LCD display (SW-900) the throttle worked from zero start only when the display shows 0 for the PAS indicator. So I didn't get your instruction about setting the KT-LCD3 to anything between 1 to 5. I ended up ordering another KT controller and finally got everything working.

Now I get it. You were right. Although counter-intuitive (or at least different from the SW-900), even if P4 and C4 are set to 0 for zero start, the PAS indicator on the display needs to be set between 1-5 for the throttle to work. With the SW-900 the 1-5 PAS settings are for pedal assist mode with non-zero start; whereas with the KTLCD3 the 1-5 PAS setting seems to be a varying power mode for the throttle. I haven't tried pedal assist mode yet but will be interesting to see how it works on the LCD3.

************* EDIT (8/5/2016) **************
I found that if you set C4 to 3, you get a zero start - even when the PAS indicator is set to 0. Cool.
The pedal assist modes 1-5 work fine too.
*************************************************

Lastly, I set P2 to 0 for the speedo to work. I have a gearless DD hub motor with Hall sensors. Not sure but I guess the 0 setting is for this type of motor with sensors so the 1-6 wheel pulse settings do not apply. Thanks again for your help!

 

[ubik76]

The LCDs are very sophisticated. They have a substantial amount of processing power, which they use to share information with the controller. Both the LCD and the controller have software in their CPUs. What that software does is decided by the programmer. The chance of advanced settings from a non-paired LCD working with any controller wouldn't be high. i.e. Kunteng LCDs work with Kunteng Controllers, but even then, they can have different software versions that doesn't match exactly.

Some Kunteng controllers have software in them that allows small changes to current and LVC, but there's nothing to say that the software in your black controller allows that.

The easiest way to change the maximum current in a controller is to shave or crimp the shunt to reduce the current, and add solder to increase it. Note that the LCD won't show any change because it will be measuring the current incorrectly. You need an external wattmeter to show the difference.

Many controllers are now using solid state SMD shunts - sometimes three separate ones, with one on each phase. For these, you need to change the resistance value by replacing them or by soldering another on top according to the formula 1/R_new=1/R_old + 1/R_added.

Hello d8veh,

you seem to be an authority about KT controllers...
I have a challenge and I’d like to know what you think…

I have a working e-bike with a very basic controller, everything works, however I am stuck with the out-of-the factory speed.
This bike doesnt even allow me to reach 25Km/h considering my weight.
All I wanted to do was to have a lil more speed, nothing crazy.
So I bought a KT controller and display thinking that I could change the speed limit.

The new controller is supposed to be better than the original, better mosfets etc..
However it doesn’t work. The display turns on the bike, I can even browse thru the parameters but it shows 0 battery charge, hence nothing works.
I tried all sort of things, like swapping the hall sensor cables to see if there was some mismatch but still nothing. Clearly there is current from the controller cause I measured 3.68V at the Throttle cable when the controller was plugged to the motor and battery.

Battery is 48V 15AH I dont think is the problem, the display turns on, it just doesnt comunicate with the motor (250W)

My naive question:
How can I proceed with modifying the new controller and make it “like” the original?

I thought about making a new one from scratch but it might be too difficult for me,
Besides I’d still have the display problem, I need one to turn on the bike, speed regulation, headlights etc..

I suspect it might be something “simple”, related only to the power circuit, perhaps once I get proper reading of the battery charge everything will work…. hopefully.

Any thoughts is greatly appreciated.