KT Controller, Smoke Leakage

[MattZ]

Apparently these things aren't sealed very well, all the smoke leaked out of mine yesterday. Less than 100 miles on the bike, very frustrating. I can't find a replacement controller that I can get in less than a month.
I have a couple questions:


Is this repairable? It looks like a couple MOSFETS burned up.

Second question - I can't find these transistors with less than a 1 month delivery date either. They're Toshiba K150E09NE transistors. I'm trying to find a comparable transistor but fear I'm getting in over my head. Specs are slightly different and I assume they all matter.
If the controller is fixable, can someone direct me to a comparable transistor?

 

[E-HP]

Yeah I've been reading up on their website and think that CA3 takes the Grin controller out of the running. It's a fairly new product using ancient technology, and expensive. I'm sure I'll need to mess with settings and can't do it without the CA3. Plus I put a lot of time and effort in running wires neatly to the controller, lengthening, shortening, soldering, crimping, heat shrinking, etc. Looking at their diagrams for CA3 everything other than phase and hall wires need to run to the handlebar. What were they serving in the meeting when they came up with that idea? They say it's to simplify things but I think it does the opposite. Might be OK for a new build but makes a retrofit a nightmare.

The cycle analysts minimizes the wires you need to run, since the throttle, and brake cable go to the the CA and one cable exits the CA, going to the controller. If you use it for PAS, then that's a second cable.
It's not a display, it's a computer, that happens to include a display. It's not pretty, but people buy it for the functionality, that isn't present in almost any other ebike components. It's also not cheap, it's a buy once, cry once kind of product.

 

[ZeroEm]

I like mine, have 3
I have a throttle, PAS, digital switch for the pas and three way analog switch to limit total power. It's not hard for me to reconfigure it all.
I track amps, watts, watt/per mile, total miles, trip miles, battery cycles, can watch my cadence to try to get it up a little.

I get a lot of use out it. You can add a logger and GPS to record your century rides.

 

[MattZ]

A shot in the dark, but have you considered putting the stock rear wheel back on and doing a Bafang mid drive conversion?

I've looked at them but what I have is a $125 used big box bike. I think with a mid drive I'd move into the mechanical problems arena real fast. Didn't want to spend a lot on the bike itself before I tested out how much fun and usefulness we'd get out of these. You can't ride out of the neighborhood here. Roads don't have shoulders so once you get on a road with highway speeds you're really taking your life in your hands. Everyone's either texting or trying out for NASCAR, and traffic's awful. It's very rare to see someone on a bike. So it's either ride around the neighborhoods we can get to without getting on a highway, or take them somewhere else like we did Saturday for a very short ride.
I did put a decent fork on it, replaced all the bearings, bigger chain ring and had a 1/4" thick stainless clamping torque arm made to handle all that torque I was expecting :lol: so I'd hate to throw that away.

I was making assumptions from the 20a/40a controller. the grin controller was just an example and its to small for what you need.
They are right can not program my controller it's the 40a and use the CA3 to control everything.

You have one on the way so all you need is a cheap backup. If you get a different controller you will need to change all the wiring connections, then change them back. Unless you put on connections like your current controller. just a thought.

I initially went round and round with the seller of the motor/controller kit. When I saw the details of the controller after placing the order the numbers didn't add up to 2000w. But they said it works fine, everyone's happy with it, and they had good reviews so I went with it. Well they can send another controller now. And a month from now shortly after I get the 45A controller I just ordered from Aliexpress they can send a new motor after I cook that. I almost never return things, but I'm going to wear out these folks and the noisy motor seller. I did order a cheap backup controller that'll be here Wednesday.
Yes the connections... I'll change them on the new controller since I already have connections matching on both bikes from trying to figure out the noise issue.

I really appreciate all the advice from you and from everyone here. I'd be banging my head against the wall without it.

 

[MattZ]

The CA does sound slick, I'll certainly give it another look once I run out of things to break on what I have now. That shouldn't take long once I get it going again.

 

[ZeroEm]

by MattZ » Sep 06 2021 4:36pm

The CA does sound slick, I'll certainly give it another look once I run out of things to break on what I have now. That shouldn't take long once I get it going again.

Get these bugs out and know not to stay on that controller to long you should be fine. Hub motors only have bearings to wear out, if you don't over heat it should last years. You have had a bad run of it. It's not always like that. Put mine together and tweaked on it here and there for the first few months. Now I just ride it and replace tires.