Throttle response/lag problems

4sken

4sken

100 mW
Joined
Nov 14, 2015
Messages
49
Location
Winnipeg, Manitoba
I've got a 1000w 16FET controller shunt modded to 2.5kw
https://www.aliexpress.com/item/48V..._6&btsid=3f63ccad-4bdb-49f7-9b18-788e4f2304a4


It's got a hell of a lot of throttle lag. I normally had no problem with it, but I recently tried a brushless 650w electric scooter and it had instantaneous throttle response and instant torque. Mine has no torque and no throttle response, at all. What's the cause of this. Is it simply the design of the controller?
 
Yup, batteries are LiPo. Max output is 17kW so that's not a problem.

I did beef the traces with extra copper wire and plenty of solder.

The problem is the controller was like this before the shunt mod; it kicks on slowly and responds slowly to throttle. I think it's intentional, to keep it from feeling jerky. However I can't get over how punchy and responsive that tiny little scooter was compared to my 2kw hub.

Could anyone recommend punchy, fast-response controllers?
 
These Kunteng controllers ramp up the phase voltage when pressing the throttle. I'm ok with that, but the problem is that they start ramping from 0V, even if the current phase voltage is higher. So when the motor is already at a higher speed (high phase voltage) it takes a couple of seconds before the controller starts to give any power at all.
 
That perfectly explains it. There's always a lag, and it changes depending on speed.

Perhaps the ramp speed can be changed; A diode or a resistor, etc?

It's more than likely baked/flashed into an IC though.
 
Sort of, I don't get torque when I want it during turns. On my gas machines the torque kicks in much much much faster than the electric setup, so I can modulate the throttle and change where the weight is on the bike. No such thing on the ebike.

I'm kind of interested in reprogramming the chip. The gas bike can hold me over while I mess with the ebike. Is it possible to reprogram the controller? It's a KT controller, turns out to be the 16 FET.
 
http://www.lyen.com/
https://endless-sphere.com/forums/viewtopic.php?f=31&t=17683
 
Yes, it has to do with the RPM, from standstill, you get instant response, and when you are going faster, the lag increases. The best you could do is not to fully release the throttle when slowing down, because the throttle response will be better. The best way to describe this is when you release the throttle the controller gives no power, no nothing to the controller. And when the motor is not spinning and you twist the throttle, the controller can give the power to the motor immediately, but when it's spinning faster, the controller has to find when and where to add power it could take a second in worst cases. But when you don't release the throttle fully, the controller still gives a little power (1A or less), but still knows where to add power, so as soon as you go on full throttle, the response will be better. I have to say that I don't understand why is this happening, it might be something else, but that thing I said works, just don't release the throttle fully when you are only slowing down.
 
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