Looking for a better controller

ubik76

1 mW
Joined
Feb 17, 2021
Messages
11
Hello everyone,

I am looking for a better controller to replace the original I found in my ebike.
would this also allow me to remove the 25 Kmh speed limit?

Not that I wanna speed like a rocket, but right now once I reach 24 it really stop pushing abruptly, plus I can feel a huge lag when I start pedalling again before the motor kicks in, so I thought perhaps a better, more expensive controller would solve all this?

Motor is 250W with 48V and a 14AH battery so perhaps I can get a better performance?

What would recommend to buy? I had a look but I get lost in all the specs...
is there something (BETTER) with similar specs of the one below that I can get without damaging battery and motor?
I need one that is small in size too.

Please let me know.

Controller.jpg

Cables.jpg
 
ubik76 said:
Hello everyone,

I am looking for a better controller to replace the original I found in my ebike.
would this also allow me to remove the 25 Kmh speed limit?

Not that I wanna speed like a rocket, but right now once I reach 24 it really stop pushing abruptly, plus I can feel a huge lag when I start pedalling again before the motor kicks in, so I thought perhaps a better, more expensive controller would solve all this?

Motor is 250W with 48V and a 14AH battery so perhaps I can get a better performance?

What would recommend to buy? I had a look but I get lost in all the specs...
is there something (BETTER) with similar specs of the one below that I can get without damaging battery and motor?
I need one that is small in size too.

Please let me know.

Controller.jpg

Cables.jpg
Changing / tweaking controllers on commercial bikes voids warranty and de facto nets you an illegal ride. If you are involved in a accident, this will be a huge problem.

Lag is due to bad or just slow pas setting.
Top speed is probably hardware set.

If you want to tweak stuff yourself, you can try a KT or controller with the open source firmware - not for beginners though. You need to figure out exact motor parameters though.
 
Clearly you'll be out of warranty, but you will be able to enjoy a MUCH better controller where you'll have some say regarding how it works. Another vote for the KT controller/display option. I've done several of these.

Yes, it will be completely unlocked. And yes, you'll very likely have more power available. Downside is you'll need to be careful using it as the motor is going to get hot and overheat if you get carried away. A few seconds is fine though.

I would go with a KT-17a. The only real trouble you'll have is with your lights, switching them with the "up" button.

If you have the 9 pin Julet going to a 5t1 cable now, make sure the controller you buy is set up for that, and not a 4t1 (w/8 pins), or you'll need to get one of those and change it - loosing the power to your headlight. Point being, not all KT-17's are the same. Be carefull picking the one you need.

Pretty sure the motor output on the controller will match/be a straight plug in if you're running a Bafang motor w/a round plug. Your pic doesn't show that so I'm not sure.
 
AHicks said:
Point being, not all KT-17's are the same. Be carefull picking the one you need.

Those Julett 9 pin cables are not all the same either.
Best you can get have 16 AWG for phase conductors and 24 AWG for signal conductors.
THe worst I have seen are closer to 20 and 30 :evil:
 
ubik76 said:
is there something (BETTER) with similar specs of the one below that I can get without damaging battery and motor?
I need one that is small in size too.
Need more information about your battery specs to know what will damage it. You likely won't damage the motor but more likely to damage the battery. At the speeds you are riding at, changing the controller will likely not net you a speed increase. Possibly better acceleration/power if your battery can handle it, but not speed.

If you have a display, that tells you anything more than the battery level, then that likely will not work with the new controller.

PS. This is assuming that you have a budget. Otherwise, you can get more speed without higher voltage if the controller has field weakening. To meet your small size requirement, the phaserunner is probably the cheapest option. If you are willing to invest $450 or so after shipping for the controller and display, you may be able to get another 4 o 5 kmh.
 
E-HP said:
ubik76 said:
is there something (BETTER) with similar specs of the one below that I can get without damaging battery and motor?
Need more information about your battery specs to know what will damage it. You likely won't damage the motor but more likely to damage the battery. At the speeds you are riding at, changing the controller will likely not net you a speed increase. Possibly better acceleration/power if your battery can handle it, but not speed.

If you have a display, that tells you anything more than the battery level, then that likely will not work with the new controller.

On the bold, no IF here. You WILL need a KT display when going with a KT controller.
 
AHicks said:
Clearly you'll be out of warranty, but you will be able to enjoy a MUCH better controller where you'll have some say regarding how it works. Another vote for the KT controller/display option. I've done several of these.

Yes, it will be completely unlocked. And yes, you'll very likely have more power available. Downside is you'll need to be careful using it as the motor is going to get hot and overheat if you get carried away. A few seconds is fine though.

I would go with a KT-17a. The only real trouble you'll have is with your lights, switching them with the "up" button.

If you have the 9 pin Julet going to a 5t1 cable now, make sure the controller you buy is set up for that, and not a 4t1 (w/8 pins), or you'll need to get one of those and change it - loosing the power to your headlight. Point being, not all KT-17's are the same. Be carefull picking the one you need.

Pretty sure the motor output on the controller will match/be a straight plug in if you're running a Bafang motor w/a round plug. Your pic doesn't show that so I'm not sure.

Hello AHicks,

thanks a lot for your advice!
I have found a KT-14A on aliexpress, which I attached here, do you think this will be ok?
I notice that the AUndervoltage value and the Current limit are different, they seem higher in the KT compared to the one I have now.
Right now I have a 4t1 (2 breaks, one to display, one to clacson horn) would another generic 4t1 work or I have to find one specific with a horn plug?
The motor is a rear hub brushless 48V with a 14 AH battery.
Please let me know.
Thanks.
Controller.jpg

KT-14A.png

KT-14A specs.png
 
I would suggest you stay with 48 volts - to keep things simple. The amperage can be increased (see the KT-17a and KT-22a for instance). Caution though, more amperage often = bigger controller dimensions. If you have the room fine, but if you don't....

Though the KT controllers are adjustable, the minimum voltage value shown there is the minimum, where the controller is going to shut down. Most folks set theirs for a little higher value.

As far as connectors, you'll need to do your own research there. Sounds like you're looking in the right places. Just realize things like the throttle connector and brake switches can be reversed male for female as well.

4t1 here stateside will be 2 brakes, the display, and a throttle. Not going to be set up for a horn.
 
AHicks said:
I would suggest you stay with 48 volts - to keep things simple. The amperage can be increased (see the KT-17a and KT-22a for instance). Caution though, more amperage often = bigger controller dimensions. If you have the room fine, but if you don't....

Though the KT controllers are adjustable, the minimum voltage value shown there is the minimum, where the controller is going to shut down. Most folks set theirs for a little higher value.

As far as connectors, you'll need to do your own research there. Sounds like you're looking in the right places. Just realize things like the throttle connector and brake switches can be reversed male for female as well.

4t1 here stateside will be 2 brakes, the display, and a throttle. Not going to be set up for a horn.

Hello AHicks,

I got KT controller and display, specifically
  • KT 14A controller
  • LCD8HU KT LCD5
pics are attached.

KT controller 14A.png
KT LCD 5.png

after connecting everything, the displays turns on but it shows 0 battery charge although is fully charged.
I tried connecting PAS sensor and throttle too for a quick test. Nothing works unfortunately

What could it be?
do you think is it solvable by playing around with the P and/or C parameters?
or perhaps a firmware thing?

I thought these controllers were universal, but for some reasons my motor doesnt really see it.

Thoughts are welcomed.
V.
 
AHicks said:
Controllers are NOT universal, nor are the required parameter (firmware) settings!

ok, thats good to know, so what would you suggest...?
 
ubik76 said:
ok, thats good to know, so what would you suggest...?

Just go back to the stock controller so you have a working ebike. If you are able to get the new controller working, with a lot of splicing and soldering, you still probably won't feel the difference between 12A of peak current and 14A.
 
Buddy will be back asking about a code that popped up on his KT displayed controller and a non-working ebike. Speed and distance is best to use a small cheap cyclo-computer wired or wireless.
For juice left in the battery its best to go by distance on the cyclo-computer and your own senses of how long and steep of hills you went up, or headwind, or how much pedaling. You get the sense if you ride a lot. If you want it for power assisted pedaling to force yourself to work out and break a sweat then a KT is a good cheap choice but you get just a good a workout with throttle only. You can utilize the cruise function of having a steady throttle to enable it, gets tricky on a bumpy riding surface. I haven't found a set and forget solution, other then a couple diy posts here on ES, setting up a resistor continuance of low voltage and clicking it a set cruise speed resistor value. The easiest way for that is a clockable rotating switch of 4+ positions to a correlated resistor value, but the throttle in off position must retain the low voltage # all the time.

Remember the more shit you hook up
the more problems that can occur
that will occur
So what do you want?
- more wires for pas
- more wires for a display
Oh you'll be back with an error code no doubt
 
:thumb: the more features the more that can go wrong. I don't mind some trouble shooting, don't want to spend all my time working on it. I like to get the basics working then add a feature one at a time. Have not hooked up my reverse yet.

ubik76 you were warned that it may not hook up and work without reworking the wiring (changing the ends). These guys can help you change the connections for the new controller to work. You will need to find a display that works with your new controller so you can adjust your PAS. Need to be ready for the hours of figuring it out.

When you want to up grade you need to look at the motor, controller and most important the battery of what it is capable of. You can push a motor into melt down and you can buy a bigger controller. If the battery can not deliver then your wasting your time.

Before spending money it is best to figure how fast your motor can go at a given Voltage, then see home many amps this will take. Then you can figure out what controller and battery you will need and have an idea of how long your motor might survive it.

I can not see a 250w motor with a 48V controller to do 15 mph/ 25kph. 48V should run most motors above 32 kph.

If you have a 36V battery then the controller may not power up. Don't give up start with your battery voltage! May need a throttle go get the motor to turn and trouble shoot PAS later.
 
Guys thanks for the replies,

battery is 48V 15AH I dont think is the problem, the display turns on, it just doesnt comunicate with the motor...

All I wanted to do was to have a lil more speed, nothing crazy.

out of the factory this bike doesnt even allow me to reach 25Km/h considering my weight etc...
V.
 
ubik76 said:
Guys thanks for the replies,

battery is 48V 15AH I dont think is the problem, the display turns on, it just doesnt comunicate with the motor...

All I wanted to do was to have a lil more speed, nothing crazy.

out of the factory this bike doesnt even allow me to reach 25Km/h considering my weight etc...
V.
Get out your soldering iron, wire crimpers, and multi-meter. The chances of the pin outs for the motor phase and hall sensor matching up between controllers of different brands are probably small. You have to decide whether you're up to the task, or just stick with the stock controller and having a working ebike.
 
E-HP said:
The chances of the pin outs for the motor phase and hall sensor matching up between controllers of different brands are probably small.

With the usual jumble of separate plugs, that's absolutely true. But so far, every 9 pin motor plug I've tried has worked without modification. At least Bafang, KT, and Ebikeling all seem to speak the same language in that regard.
 
Chalo said:
With the usual jumble of separate plugs, that's absolutely true. But so far, every 9 pin motor plug I've tried has worked without modification. At least Bafang, KT, and Ebikeling all seem to speak the same language in that regard.

That's good info! Thanks.

Hard to believe that there are any standards, but maybe there's light at the end of the tunnel.
 
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