Limitting KT Controller Power (Believe it's a clone)

lumisoft

New Member
Region
United Kingdom
Ok. So I have Carrera Crossfire e bike - it has SR Suntour 250W hub motor, 36V 11.86aH battery, what I believe is KT Clone Controller, Throttle, LCD3 - no PAS sensor(Want it to work on throttle only). The controller is rated for both 36V and 48V. The current battery seems to be too limited and cut's out under max throttle. I believe the throttle is too sensitive as well - it's hard to throttle slow enough to prevent it from cutting out. Now this is where my electrical engineering knowledge stops - I need to either limit throttle or limit the controllers output? C setting forlimitting Amps and Voltage are not doing any good - not too sure how to limit it to the level I need. It could be the Motor as well - 250W is not a lot I know. Plan on getting another Hub motor(750W) and 48V battery in future but not anytime soon so would like to get the current setup running. Have also replaced the current controller with exactly same make model - just to eliminate any possible issue with the controller itself. Just to clear the posibility of faulty hub or battery - it works like a charm with the original Carrera controller. Any suggestions?
 

AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
No clue what you've tried already, so I have to ask, have you looked at the C5 parameter? Generally, you would set it to get your max available power you want going to the motor into the ball park, then use C14 to fine tune the power available when using PAS 1

Regarding throttle cut out at max throttle, assuming a fully charged battery when that's happening, you MIGHT try lowering the voltage that happens at using the C12 parameter.

Regarding throttle resolution/sensitivity, you're generally stuck with the limits of the throttle you purchased. Maybe have a look at the amount of throttle travel on the one you have, and swap it out for one with more travel? More travel SHOULD give you better resolution.
 

JES2020

Well-Known Member
Region
Other
Ok. So I have Carrera Crossfire e bike - it has SR Suntour 250W hub motor, 36V 11.86aH battery, what I believe is KT Clone Controller, Throttle, LCD3 - no PAS sensor(Want it to work on throttle only). The controller is rated for both 36V and 48V. The current battery seems to be too limited and cut's out under max throttle. I believe the throttle is too sensitive as well - it's hard to throttle slow enough to prevent it from cutting out. Now this is where my electrical engineering knowledge stops - I need to either limit throttle or limit the controllers output? C setting forlimitting Amps and Voltage are not doing any good - not too sure how to limit it to the level I need. It could be the Motor as well - 250W is not a lot I know. Plan on getting another Hub motor(750W) and 48V battery in future but not anytime soon so would like to get the current setup running. Have also replaced the current controller with exactly same make model - just to eliminate any possible issue with the controller itself. Just to clear the posibility of faulty hub or battery - it works like a charm with the original Carrera controller. Any suggestions?
Why didn't you get a replacement Carrera controller???
 

lumisoft

New Member
Region
United Kingdom
Ok - not going to go into too much detail - Halfords is just... Just suggestion to everyone - NEVER BUY EBIKE FROM HALFORDS. So Long story short(Already have a thread here explaining how it went) Halfords told me that I would need to wait for months until their SPECIAL Technician could look into it and determine the issue and then MORE MONTHS to get the parts ordered (Shortage of course) and THEN more months to get the technicial to fix it. Rough eta from them - 5 months. FOR 5 MONTHS I would have to leave the bike there - sooo - no chance - I just took it on my own hands to fix it - plus wanted the throttle.

C5 is set to 12 - I though it was just to display the batteries capacity correctly.
 

AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
Ignore that - mistaken it for P5 - no C5 is set to lowest
I confuse the C parameters and the P parameters constantly - have to watch myself pretty carefully there. I'm assuming you are using a manual somewhere? If you look at that, C5 00, 01, and 02 selections are not explained very well. Not sure here how they function exactly. C5=03 setting is very clearly labeled "Maximum current value÷2.00". That would be the lowest I would use. Which leaves me wondering what, exactly, setting have you chosen?
 

harryS

Well-Known Member
Hey Lumisoft, what's the current rating on the controller label? I would expect at most a 20A peak controller for a store bought 250W ebike.

What happens when battery cuts out? Does display go blank, which is battery BMS doing it. Or does battery icon start blinking, which means controller detected less than 30V. What voltage level does the LCD3 say when this happens? Maybe under 35V?



KT_20.jpg
 

harryS

Well-Known Member
So you put on your own controller/LCD? At what voltage does this happen? I suspect a crap battery.

I can run a 20A KT controller on a 36V2AH weedwhacker battery,
 

lumisoft

New Member
Region
United Kingdom
i just bypassed BMS for discharge. Works like a charm - don’t expect long life - should be fairly safe for discharge only. Will plan on buying 48V battery in future.