How do I setup my KT display settings?

[PCeBiker]

The first thing that I figured that I needed to do was get the speedometer reading correctly, and it just happened to be dead on with P1=40 and P2=6 BUT the speed would only go up to 28.8 kph then I could feel the power cutting in and out to maintain that speed, and the watt meter was showing it as well.

The number of magnets and the gear ratio should should have nothing to do with a speed limiter other than reaching the maximum RPM of the motor and I didn't reach maximum motor RPMS.

I did set my wheel diameter at 29 inches because that's the overall diameter of the wheel, but it's a 26 inch rim.
So I'm going to set my wheel size at 26" next time and see what that does.
As long as my bike will go the speed limit of 32 kph I'll be happy, but if my speedometer reads correctly, maybe I'll set the wheel diameter to the smallest size and see what that does.

All of that should have nothing to do with my riding style unless my style is to go as fast as possible, and it's not.


I did play with the C4 settings and found that I like C4=4.

With that setting I can use my Throttle Gears just like PAS modes.
Each gear is a little faster and I can limit the power and/or speed (I'm not sure yet) from between 20% and 60%.

That works pretty cool for me because I want to reduce the power output of my controller anyway, and I don't have PAS modes without a PAS sensor.

I was hoping that the Throttle Gears would lock in on a set power output, but that doesn't appear to be the case.
It is still set to speed, but limits the power to get to that speed, and I'm pretty sure that if the bike can't reach the set speed with the set power output, then it won't reach the set speed? (like a headwind or uphill)


What I was hoping for was to be able lock in an adjustable set power output regardless of speed.
I'm pretty sure my throttle works that way and holding the throttle steady will hold the power steady, so I will go faster downwind than upwind.

So @6zfshdb 's cruise control modification might still be something I do in the future.

Adding a Rotary Dial Speed Control

I occasionally get a cramp in my right hand when using my half grip twist throttle. As a remedy, I built this small control box as an alternate way to adjust speed. In doing some research, I discovered a 3 wire hall effect throttle can be emulated with a variable resistor. I wired the control...

electricbikereview.com

 

[PCeBiker]

I went for another test ride yesterday and got my speed up to 32 kph and my speedometer reading accurately.

This is a picture of my settings to get my ebike to 32kph with an accurate speedometer,..

But, there's something weird going on.

My ebike WILL NOT go faster than 32 kph.
I tried everything including wheel size, number of magnets, gear ratio, top speed limit, P1 from 20-220.
The only thing that would change was what the speedometer was reading, but not the actual speed.

I can't figure out why wheel size doesn't affect the actual speed. The same motor installed in a 20 inch wheel would have to spin faster to go at any given speed, but all that changed was the speedometer reading.

I'm thinking that it's using GPS?
It was sold to Canada with a 32 kph speed limit.


Either way, I don't care.
I didn't install the KT controller/ display to go faster, I just wanted to control the power, and it is working Great for that!!

I set my C4 to 4 and turned it down to 30%, and set my C5 power to maximum.

These are the resulting maximum speeds for each throttle gear.
Throttle gear 0 deactivates the throttle.
I adjusted my settings so that the bike turns on with the throttle inactive. (0)

Notice the voltage sag while drawing more power for faster throttle speeds.
I found that at ~43 volts, the voltage would sag enough to kick out the controller, but I just had to wait for a few seconds for the voltage to recover, and the controller turned back on.
I would then turn down my throttle one notch at a time to prevent my voltage from sagging enough to cut out the controller.
I can go a long way on throttle speed 1 or 2 after throttle speed 5 cut me out.


I was watching the watt meter while accelerating from a stop and it went to at least 1100 Watts.
So the current isn't being limited to 30%.
I have a 25 amp controller.
1100 Watts at 54.6 volts is 20.1 amps and at 40 volts is 27.5 amps, so I am pulling maximum power out of my battery, at least until I reach 32 kph (a few seconds) where the current drops to whatever it takes to maintain the set speed (~100-400 Watts)



I made a Coles Notes version of the Display manual for easier reference,..

 

[PCeBiker]

I pedaled the bike for a while with the power off, and it was fine.
It might be a ~75 pound ebike, but with street tread tires filled to 30 psi, it doesn't have much rolling resistance.
It's certainly not like I'd have to get off and push it if I ran out of juice, unless I've got a 25 mph headwind.
Even then, I could probably still pedal it slowly in first gear.

The smooth tread tires are fine in the dirt too.
It's not like I have enough power to spin the tires. I just have to get a feel for cornering with limited grip, but I'm getting used to it.

 

[Slaphappygamer]

BUT the speed would only go up to 28.8 kph then I could feel the power cutting in and out to maintain that speed

This is super awkward. When I was testing the settings, I found this same result. I ended up removing the speed limit. I guess I could’ve toned down that max amp usage, but with a 20mph limit, I’d have the same thing happen again. I watch my speed and self regulate, as best I can.

FWIW, I have a 25A KT controller with a Shengyi hub motor and use these settings.

 

[PCeBiker]

This is super awkward. When I was testing the settings, I found this same result. I ended up removing the speed limit.

I have my speed limit set to 72 kph and it doesn't make any difference with my actual top speed.
I did enter a 20" wheel and the speedometer was reading 79.9 kph and I didn't reach 32 kph, probably because it reached the 72 kph limit?

I guess I could’ve toned down that max amp usage, but with a 20mph limit, I’d have the same thing happen again.

I'm mostly interested in turning down the amps so I don't overwork the motor, controller, or battery.
At over 1100 Watts I'm pretty close to the maximum power of everything.

I'm sure that if I had a strong head wind and I was in throttle gear 5, I could be using more than 1100 Watts continuously to maintain a speed of 32 kph.
That wouldn't be a good thing.

I watch my speed and self regulate, as best I can.

I figure that I don't have to worry about my speed, because the bike won't go faster than 32 kph.
But I'll keep a close eye on my Watt meter.
I think that I'll cut my power in half again and see how that affects the Wattage.

Both of my Das-Kit Displays were speed limited to 32 kph as well.
I could change all the settings, and all it would do is change the reading of the speedometer but not the actual speed.
I don't know how that is being done?

FWIW, I have a 25A KT controller with a Shengyi hub motor and use these settings.

I have a 25A KT controller as well, but my original Das-Kit Controller was 22A, so I do want to turn the power down somewhat at least.

I'm thinking of cutting the controller power in half again (12.5 amps) and see how that is.

I'm more interested in how long I have for a ride before I run out of power.
If I go slow and keep my Watts down to 100-200 Watts, I should have more time for a ride.

I'll see what it's like with the maximum current cut in half.
If I end up with sluggish acceleration, I'll turn it up a bit.

 

[PCeBiker]

This is super awkward. When I was testing the settings, I found this same result. I ended up removing the speed limit.

Will your ebike go faster than 20 mph?
Did you check your speed with GPS?

FWIW, I have a 25A KT controller with a Shengyi hub motor and use these settings.

View attachment 151040

Your settings are pretty close to mine, except when I enter P2=1, my speedometer reads something like 70 kph.
I don't get it?

I should have a speed pulse of 1 not 6, but those were my settings that got my ebike going 32 kph with the speedometer reading accurately.

 

[Slaphappygamer]

Will your ebike go faster than 20 mph?
Did you check your speed with GPS?

Yes, I can get to almost 30mph. I only hit that if I’m crossing busy street.

Have you tried your P2 at 0? Because technically, “If users didn’t configure the pulse signal system, and then P2 parameter
setting can be 0.”. This is a quote from the manual.

 

[PCeBiker]

Yes, I can get to almost 30mph. I only hit that if I’m crossing busy street.

Huh?
When I hit the throttle, it draws up to 1100 Watts, then when I hit 32 kph, the power drops right off.

Have you tried your P2 at 0? Because technically, “If users didn’t configure the pulse signal system, and then P2 parameter
setting can be 0.”. This is a quote from the manual.

OK.
I'll give that a try.

I'm kinda thinking that it's a Canadian thing?
I think that they might have to restricted to be allowed into Canada?

My two Das-Kit displays were restricted to 32 kph, but I could have bought one from the US that would get me to ~48 kph.

Canada is really cracking down on the 20 mph ebike law.

 

[Slaphappygamer]

Oh wow. That could be. The store, perhaps, recognized your shipping location and flashed firmware accordingly to conform to local regulations. That is a crackdown!

I wonder if you can actually get above 32kph with PAS, not on throttle. If you wanted to hook it up and try.

Maybe also, you can contact the seller and confirm if the limit is in place due to your local regulations.

 

[PCeBiker]

Oh wow. That could be. The store, perhaps, recognized your shipping location and flashed firmware accordingly to conform to local regulations. That is a crackdown!

That's what I'm thinking.
But I don't know how it works?
My T1000 Ebike has 26X4.00 wheels and there is an F1000 with 20X4.00 wheels that uses the same motor (as far as I've been able to find out).



So how does the display know what size wheels the ebike has to adjust for a faster spinning smaller wheel?
That's why I think it's using GPS?
Unless the F1000 just doesn't go as fast? Or there's some kind of communication going on between the controller, display and motor?

I wonder if you can actually get above 32kph with PAS, not on throttle. If you wanted to hook it up and try.

That may be the case. I know that my original C7 Das-Kit Display could be replaced with an older H7 (or is it L7?) display that would leave the power on after 32 kph if you kept pedaling, but they stopped doing that to conform with Canadian law a few years ago.

Hooking up my PAS sensor would be a PITA though and I don't want to bother.

Maybe also, you can contact the seller and confirm if the limit is in place due to your local regulations.

I guess that I could, but I don't really care that it only goes 32 kph.
The battery drains a lot faster at higher speeds and I only went ~27 km on my 21AH 48V battery, from full charge to when my controller started to cut out.

If my bike would go 50 kph, I would probably get less than half that range and kill my battery in less than ½ hr.

I found out too, that a battery doesn't deliver its full charge when it is drained quickly and the lost battery capacity is just turned into heat inside the battery. Exactly where I don't want things to get hot.
And draining the battery quickly is also hard on the battery and shortens its lifespan.

I'm pretty sure that I'm going to install my Motor Speed Controller,..



I can use it to set an exact power output then I can do better with hypermiling to get the most range.
I can take advantage of a tail wind to increase my speed and I can start to pedal with a headwind if my speed slows too much.

My cruise control with my display works nicely but it maintains a set speed where the Wattage keeps jumping around to maintain that speed.
I'm more interested in maintaining a power output regardless of speed.

 

[Slaphappygamer]

Yea, that would be a pain just to test. Unless you wanted to simulate a bottom bracket. You boy, that'd be another rabbit hole to dive into. LOL.

I'm interested, though, to see how your Motor Speed Controller goes. If I did'nt have that surging power to maintain 20mph, I'd probably use that. Curious where you'd mount this too and how you'd wire this in.

 

[PCeBiker]

Yea, that would be a pain just to test. Unless you wanted to simulate a bottom bracket. You boy, that'd be another rabbit hole to dive into. LOL.

I could probably make a simple pulse generator to simulate a PAS sensor, but I'd still have to open up the controller and wire it in.
I cut the wires off for the sensor at the circuit board.
I left just enough wire to identify the wires and be able to connect new wires if I ever wanted to connect a sensor.



(It's the three wires circled in blue.)

I'm interested, though, to see how your Motor Speed Controller goes. If I did'nt have that surging power to maintain 20mph, I'd probably use that.

You probably do have your power varying if you're e-bike is maintaining a constant 20 mph.
The only way to maintain any speed is to vary the power to keep the speed steady.
Keep an eye on your watt meter to see what the power is doing.

I don't know how many Watts your motor is rated at, but if it's a 500 Watt motor, dumping 25 amps into it might be too much.
You can burn out your motor, or the wires and connectors can melt.

The general rule is that you can only run it at full power for less than 30 seconds, then you have to back off the power and give it time to cool off.

Curious where you'd mount this too and how you'd wire this in.

I'm going to have to figure out a way to mount it with it looking too trashy.
I don't have much experience with fabricating things, and using duct tape and coat hangers won't cut it.

I managed to hook up two throttles to my ebike before.
I just connected the three wires together in parallel and it worked.
The +5 Volts supplied by the controller powered both throttles and which ever throttle was set the highest over road the other.

I used @6zfshdb 's diagrams to figure it out.

Adding a Rotary Dial Speed Control

I occasionally get a cramp in my right hand when using my half grip twist throttle. As a remedy, I built this small control box as an alternate way to adjust speed. In doing some research, I discovered a 3 wire hall effect throttle can be emulated with a variable resistor. I wired the control...

electricbikereview.com

His method uses batteries to power the circuit, and I just hooked the two throttles together to see what would happen, and it worked.

Using a speed controller (potentiometer/variable resistor) with resistors emulates a HAL sensor throttle, and some throttles use a potentiometer instead of a HAL sensor.

Using the speed controller, or holding the throttle steady at any position should lock in an exact power setting not a speed setting, so if you are going uphill holding the throttle steady, you will go slower than going downhill.

 

[Slaphappygamer]

Maybe you can put that pot in the end of a pvc pipe. It would protect the wires and you'd probably have an easier time mounting it.

I think I'm treating my motor well. It's rated (not sure if rated at peak or nominal) at 48v 22a. It has 16 AWG phase wires. So I think 25a would be my absolute max. I have my controller set for 22a. I briefly hit 1100 (5-8 seconds) once along my commute.

 

[PCeBiker]

Have you tried your P2 at 0? Because technically, “If users didn’t configure the pulse signal system, and then P2 parameter
setting can be 0.”. This is a quote from the manual.

I gave that a try, and it didn't work.
My e-bike actually went slower.

The speedometer was reading 34 kph but my actual speed was about 28 kph. I probably could have adjusted P1 to get it back up to 32 kph and reading correctly but I just put P2 back to 6. That way my speedometer reads about 1 kph faster than I'm actually going.

So, my ebike will not go faster than 32 kph, and luckily that's fast enough for me so I don't have to try and figure what's going on, how it's being done, and try to "fix it"

And with that being said, both my T1000 and the F1000 are supposed to have a "G20" motor but the F1000 has "Mag" wheels with 6 magnesium "spokes" that attach to the the motor and my e-bike has regular spokes, so the motors are probably different, at least as far as how they attach to wheel, so I'm thinking that maybe they are a different internally, with a different gear ratio to compensate for the different wheel diameters, so maybe the actual armature RPMS are the same at the same road speed?

That way, both bikes would have the same torque and maximum motor speed and the speed pulse signal would be the same for both bikes.
That way the speed could be limited to 32 kph without using GPS.
(I'm just speculating)

Maybe you can put that pot in the end of a pvc pipe. It would protect the wires and you'd probably have an easier time mounting it.

I'll figure something out. The potentiometer is kinda big as it is and I don't want something honking huge on my handbars, so I don't want to put it in a box.



EDIT:
Holy Crap !!
Did this ever come together nicely !!

I popped the handlebar bracket off my reflector and the potentiometer fits it perfectly.
I can reach over with the edge of my thumb and roll the dial.
It's perfectly Ergonomic. I don't have to move the rest of my hand.





I can attach the wires then coat the wires and connectors with black silicone.

Then maybe I'll remove my left crank arm, rotate it 180°, and reinstall it.
Then I can use my pedals as foot pegs.



I don't like my legs being at different heights, and my pedals are strictly for emergencies anyway.
I'll just reinstall them proper in an emergency.
Pedaling is for suckers.

Maybe you can put that pot in the end of a pvc pipe.

I put my pot in a glass vape pipe.
Plastic burns.

 

[Slaphappygamer]

Wow. Looks great!

 

[PCeBiker]

Wow. Looks great!

Yeah.
No duct tape or coat hangers.

 

[PCeBiker]

Here's a link to the potentiometer that I bought, if anyone is interested.

https://a.aliexpress.com/_mPZtN6c

It's not connected yet, but I'm 95% sure that I can hook the three wires up directly to the other throttle (along with the two resistors) and it will work.

And I can shut both throttles down by hitting either brake or turning my "throttle gear" down to zero.