What is bottlenecking me?

[stonestonestone]

I'd go with the 17a model. On the KT controller you can modualte the power level (amps) going to the motor

with that logic, I might as well get the 20A, as I could modulate the amperage on the controller-right?

 

[Tom@WashDC]

with that logic, I might as well get the 20A, as I could modulate the amperage on the controller-right?

correct.

 

[Slaphappygamer]

Here is a link to the LCD8H manual. The C5 setting is what you would change to achieve the max current you want to allow. Do look at the other settings so you can gather other info you may need to properly set up your bike.

 

[PCeBiker]

My previous controller fit pretty snug- so I'm only going with something that size or smaller

All the KT controllers that I found on AliExpress listed the measurements.

Generally speaking they have 6, 9, or 12 Mosfets.

The Mosfets have been improving over the years and became more efficient, so the old 17 amp controllers are now capable of about 22 amps with the same size box.

You should be able to measure your current controller to compare with what you're interested in buying.

Sinewave is generally better than square wave.
Square wave is more efficient for the controller but it's noisier for both the controller and motor, and the efficiency saved by the controller is then wasted as extra heat in the motor.
Sinewave is kinder to your motor by providing smoother and cleaner power.

The KT controller also comes with JST connectors or waterproof connectors, so you'll need to pick the one that will plug into your ebike.

 

[PCeBiker]

with that logic, I might as well get the 20A, as I could modulate the amperage on the controller-right?

Getting a more powerful controller and turning it down, really helps to keep it from getting hot.
You'll get more life out of your controller.

 

[Gionnirocket]

All the KT controllers that I found on AliExpress listed the measurements.

View attachment 176728View attachment 176729View attachment 176730View attachment 176731View attachment 176732


Generally speaking they have 6, 9, or 12 Mosfets.

The Mosfets have been improving over the years and became more efficient, so the old 17 amp controllers are now capable of about 22 amps with the same size box.

You should be able to measure your current controller to compare with what you're interested in buying.

Sinewave is generally better than square wave.
Square wave is more efficient for the controller but it's noisier for both the controller and motor, and the efficiency saved by the controller is then wasted as extra heat in the motor.
Sinewave is kinder to your motor by providing smoother and cleaner power.

The KT controller also comes with JST connectors or waterproof connectors, so you'll need to pick the one that will plug into your ebike.

What about the ones you didn't find

 

[Tom@WashDC]

What about the ones you didn't find

Such a contrarian!

 

[PCeBiker]

What about the ones you didn't find

I just keep looking, and I always see measurements.

 

[Slaphappygamer]

Honestly, I find it fun to dig all up in an items description. Add all the info up, is it legit? I’ve always been a crappy student, but I’ve learned how to do my homework now.

 

[PCeBiker]

Honestly, I find it fun to dig all up in an items description. Add all the info up, is it legit? I’ve always been a crappy student, but I’ve learned how to do my homework now.

The hardest part for me was figuring out how to join AliExpress then learning how to use the website and find the information.
I spent over 3 dozen hours trying to finally buy something.

This is what I decided on,..

I figure that they aren't going to lie about the dimensions, but they could lie about the power, because everyone wants More Power.

I have seen mistakes though where the measurements weren't listed properly.

My forks show a steerer tube measurement of 250mm, but it was actually 250mm measured to the bottom of the fork brace.

 

[stonestonestone]

All the KT controllers that I found on AliExpress listed the measurements.

View attachment 176728View attachment 176729View attachment 176730View attachment 176731View attachment 176732


Generally speaking they have 6, 9, or 12 Mosfets.

The Mosfets have been improving over the years and became more efficient, so the old 17 amp controllers are now capable of about 22 amps with the same size box.

You should be able to measure your current controller to compare with what you're interested in buying.

Sinewave is generally better than square wave.
Square wave is more efficient for the controller but it's noisier for both the controller and motor, and the efficiency saved by the controller is then wasted as extra heat in the motor.
Sinewave is kinder to your motor by providing smoother and cleaner power.

The KT controller also comes with JST connectors or waterproof connectors, so you'll need to pick the one that will plug into your ebike.

@Gionnirocket there's another more obscure one...took me a while to find it. Listed measurement 96x61x35mm

 

[stonestonestone]

Here is a link to the LCD8H manual. The C5 setting is what you would change to achieve the max current you want to allow. Do look at the other settings so you can gather other info you may need to properly set up your bike.

Could I do this on one of the cheaper displays? Lcd3 or Lcd5?

 

[Slaphappygamer]

Yes. Here is a link to lcd3 and the lcd5 manuals. They all look different, but function the same.

 

[PCeBiker]

Could I do this on one of the cheaper displays? Lcd3 or Lcd5?

There are lots of KT displays to choose from, and they will all work, but some of them don't have all the adjustable settings available.

The LED880 doesn't have any adjustable settings.

The LCD3 and the LCD8 have all the same settings (except for one extra setting on the LCD8 that isn't worth mentioning) and all the displays are a bit cheaper if they don't have a built-in USB port.

The LCD3 is apparently easier to see in direct sunlight whereas the LCD8 screen washes out in the sun ,and is hard to see.

I'm not sure what the other displays offer for settings.

 

[PCeBiker]

Yes. Here is a link to lcd3 and the lcd5 manuals. They all look different, but function the same.

@Slaphappygamer , do the JST versions of the displays come with a long cable to reach down to the controller?

I bought the waterproof plug version, and the display uses an 1-5 cable to connect the display, throttle, and brake switches to the controller.

 

[Slaphappygamer]

It came with a long, continuous, cable with a JST end. Just like this.