Lishui Controller Modification - Firmware Flash Project

[Sparksandbangs]

As it stands these are my initial feelings on the Lishui controller compared to the KT.



Positives

- Graduated legal throttle rather than an on off switch

-Ability to increase the power on the start assist. On the old controller it always felt a bit weedy. Strangely on my other bike it felt too much.

- Power is increases the faster you pedal. At first I thought I would hate this but it makes sense when you are manoeuvring slowly through traffic. With the KT I found myself feathering the brake and slightly turning the pedals then back pedalling to achieve the same effect. It also feels more natural. Should you need a boost then the throttle can be blipped.

- Ability to manipulate the power assist levels as I see fit

- More configurable


Potential Positives

-Could put in a torque sensor should I feel the urge. Not on the radar but the potential is there.

Negatives

-It's a 48V system. I've lost the ability to use my 36V battery but thinking about it I can't see a good reason why I shouldn't try. The voltage levels would need adjusting but I can't see why not having a condition that says battery voltage below 44V means its a 36V battery and above it's a 48V couldn't be programmed in.

 

[saneagle]

I've tried controllers that give power in proportion to pedal speed, and I found them absolutely diabolical. In any gear, you start to pedal faster and faster as more power comes until you have to change up, which reduces pedal speed, which reduces power, so you don't have enough power to maintain that gear, so you change down, get a rush of power and go through the same thing again and again without ever reaching a balance of motor and pedal power. It's the sort of idea that sounds quite promising until you try it. After one ride of each, I chucked them in the bin. They were quite powerful controllers. Maybe you don't notice it so much with weak ones, like the difference between speed control and current control.

 

[Sparksandbangs]

I've tried controllers that give power in proportion to pedal speed, and I found them absolutely diabolical. In any gear, you start to pedal faster and faster as more power comes until you have to change up, which reduces pedal speed, which reduces power, so you don't have enough power to maintain that gear, so you change down, get a rush of power and go through the same thing again and again without ever reaching a balance of motor and pedal power. It's the sort of idea that sounds quite promising until you try it. After one ride of each, I chucked them in the bin. They were quite powerful controllers. Maybe you don't notice it so much with weak ones, like the difference between speed control and current control.

That's not how it felt. Maybe the torque simulation is more nuanced, who knows? Well maybe someone on the German forum but that would mean reading through 150 pages translated by Google.

I will give it a week of riding. I'll look out for the behaviour that you mentioned and report back. It does have a legal throttle. I think someone once mentioned that torque simulation and a legal throttle is best there is. ;-)

It's officially a 25A controller by the way.

 

[saneagle]

That's not how it felt. Maybe the torque simulation is more nuanced, who knows? Well maybe someone on the German forum but that would mean reading through 150 pages translated by Google.

I will give it a week of riding. I'll look out for the behaviour that you mentioned and report back. It does have a legal throttle. I think someone once mentioned that torque simulation and a legal throttle is best there is. ;-)

It's officially a 25A controller by the way.

The KT settings are P4=1 and C4 =3. It gives you a throttle that gives 4 mph without pedalling, max speed when pedalling (15.5 mph set) and maximum power when pedalling. That way, you get start assist and an instant max power over-ride for whatever pedal assist level you have set, so you can leave it on a lowish level, and every time you need a burst of power, you use the throttle, which saves going up and down the power levels all the time.

That's for a standard KT controller. I don't know how any of it relates to your software version.

 

[Sparksandbangs]

The KT settings are P4=1 and C4 =3. It gives you a throttle that gives 4 mph without pedalling, max speed when pedalling (15.5 mph set) and maximum power when pedalling. That way, you get start assist and an instant max power over-ride for whatever pedal assist level you have set, so you can leave it on a lowish level, and every time you need a burst of power, you use the throttle, which saves going up and down the power levels all the time.

That's for a standard KT controller. I don't know how any of it relates to your software version.

The legal settings are the same. 6kmph without pedalling. Pushing the throttle while pedalling gives a graduated output though. Push it all the way and you get max power, less that and you get proportionally less power.

 

[Sparksandbangs]

Previously I'd set the wheel circumference by measuring from the floor to the centre of the hub, multiplying it by 2 and then by Pi. As a back up I ran the wheel one revolution on and then measured how far it had travelled. Both were within 5 mm So should be accurate.
Sellotaped my phone to the frame and set off GPS speed measuring app and it appears to be spot on.

Still cutting out at just over 16.5mph. Played around with the gear ratio in the code to see if it would do anything. Matched the P1 setting in the LCD3 just in case it is talking with the controller and modifying the setting. Did naff all. Still cutting out at the same speed.

Looked at the code it appears that it allows a 2kmph overshoot and then restarts assistance when it drops back to 25kmph. Changed it to 25/23kmph and now it cuts out dead on 25.

Noticed that battery bars haven't moved. Dug into that section of code and it is set for 36V. Couldn't remember where the levels are with the Kunteng controllers so set it up 54.6 full 52/50/49/48 47 Empty. Seem to remember that the bars were pessimistic anyway so should be fine.

Push assist current seems a little bit keen so dropped it in half will see how it goes on.

 

[guerney]

If you pedal after the cutoff downhill, is pedal assist slow and puny when it resumes?

 

[Sparksandbangs]

If you pedal after the cutoff downhill, is pedal assist slow and puny when it resumes?

Good question. I have my 28mph downhill followed by a steep uphill on Monday. It will be a good test. This will be the first time that I have had an accurate speed reading while attempting it.

Last time I did the hill I had disconnected the white speed wire so had no display and no cut off, so a bit of a cheat all round. The time before I was using the hall sensors so as soon as it went over the limit the speed jammed at 16.8mph on the display.

 

[saneagle]

If you pedal after the cutoff downhill, is pedal assist slow and puny when it resumes?

That comes mainly from the behaviour of the motor, not the controller. The only thing the controller does is get the cut-off speed from the hall sensors, so the motor keeps spinning at 15 mph if you pedal downhill.

 

[Sparksandbangs]

I now have a fairly good idea which parameters from the Kunteng display actually do anything.

The assist level is transmitted to the controller and changes the level.

The maximum speed is transmitted and changes the parameter in the modified Lishui controller.

C3, C6, C7, C8, C9, C10, C11 are all parameters that are internal to the display so work as normal.

P1 works in a fashion. It is not stored in the controller. The Gear ratio is set in the config file and can only be changed by flashing to the controller. The controller then calculates a speed reading from this gear ratio. If P1 is set to a different value in the display then this value is used to modify the calculated speed returned to the display. So by adjusting it up and down you can calibrate the speed. If you are using the speed signal from the white wire this setting does nothing. It doesn’t matter what you set it to.