KT 30A 12MOSFET controller - regen and programming?

[c111jp]

Does anyone know anything about these 30A KT controllers? https://www.aliexpress.com/item/100...16821775336528932ef997!12000032681124083!im!!

I'm linking the one from other seller but KT is selling same controller on their page, they just didn't post info for 30A one for some reason.

Here it is from KT https://www.aliexpress.com/item/100...16821784215994953ef997!12000030823269787!im!!

They have few different 30A controllers but I am specifically interested in this one because of dimensions and I don't need waterproof connectors.

I've burnt my controller by accident (genius, there is another thread) so I want to buy this one. It seems perfect as it's slightly smaller in dimensions than standard 12fet controllers, it's black and everyone seem to praise KT controllers. Problem is, I've asked both KT and other seller, and both say it doesn't have regen function. I asked if it can be enabled through display and they say it can't which I find weird.

I want to use it without display.
How would one connect to this controller for purpose of programming? What exactly would be needed in terms of interface / cable, software, mods etc? Can it be programmed through display port (5pin) and USB TTL? If true that it doesn't have regen, would it be possible to enable it by shorting certain pins? If somebody has pictures of both sides of PCB for the exact same controller, it would be awesome!

Other thing I'm worried about is if the default settings such as top speed and other are severly limited and I can't change it without display so ideally I hope it has pins that can be jumped on PCB for such stuff.

Another thing I'm wondering is if when using display, changing settings would store changes in the display or controller itself making them permanent.

If anyone has any more info on this exact 30A, 12FET 146*62*38mm size controller, that would be awesome.

Thanks!

 

[AGS]

I don’t think the controllers that you have linked to are manufactured by KT.

 

[From-A-To-B]

I don’t think the controllers that you have linked to are manufactured by KT.

Same. That display is not a KT display.

I've burnt my controller by accident (genius, there is another thread) so I want to buy this one. It seems perfect as it's slightly smaller in dimensions than standard 12fet controllers, it's black and everyone seem to praise KT controllers. Problem is, I've asked both KT and other seller, and both say it doesn't have regen function. I asked if it can be enabled through display and they say it can't which I find weird.

I want to use it without display.
How would one connect to this controller for purpose of programming? What exactly would be needed in terms of interface / cable, software, mods etc? Can it be programmed through display port (5pin) and USB TTL? If true that it doesn't have regen, would it be possible to enable it by shorting certain pins? If somebody has pictures of both sides of PCB for the exact same controller, it would be awesome!

Other thing I'm worried about is if the default settings such as top speed and other are severly limited and I can't change it without display so ideally I hope it has pins that can be jumped on PCB for such stuff.

I’ll only speak to some of this, the parts I have experience with. I don’t have your exact controller, but I have used 4 KT controllers.

Top speed is dictated by battery voltage and motor KV. The controller can get in the middle of that and reduce top speed with programming, but it cannot boost top speed beyond the physics of KV and voltage. Going from memory, I’ve set my KT controller to max out the top speed (72kmh/44mph). My bikes will make it up to ~30mph, limited by KV and voltage, so I’ve set the KT controller to have no programming limitation on top speed.

Every KT controller I’ve worked with has regen that can be enabled in the menus, along with options for regen strength.

You’re talking about jumping pins on the board— FWIW, for basic functionality, everything should be programming with the display and keypad. There’s nothing I’ve wanted to adjust on my KT controller, on my basic ebike, that couldn’t be done through the display. No pin jumping required.

I’m unsure if KT controllers will operate without the display. They need the push button key pad to turn on, which is attached to the display.

 

[AGS]

Real KT controllers can be operated without the display once they have been configured. But a couple of jumpers are needed on the display plug into the controller. My KT controller came with the jumper plug already plugged in and I removed it to plug in the display.

 

[AHicks]

FYI - the parameter configurations are held in the display. There may be some you can hard wire with jumpers, but I would want more specific info if I were planning on running a KT without a display....

KT controllers all have "KT" included in the controller model number.....

 

[c111jp]

Thanks for your input all. Interesting since the seller selling it is named KT (Kunteng) https://www.aliexpress.com/store/911380051?spm=a2g0o.detail.100005.1.468660e3CLudf3
So fake profile? Does anyone have a real source where I could get their controllers? Or can somebody recommend something similar to this but kinda "verified"?
Really like the size since most 12Fet controllers will be close around 180x80x40

Same. That display is not a KT display.


I’ll only speak to some of this, the parts I have experience with. I don’t have your exact controller, but I have used 4 KT controllers.

Top speed is dictated by battery voltage and motor KV. The controller can get in the middle of that and reduce top speed with programming, but it cannot boost top speed beyond the physics of KV and voltage. Going from memory, I’ve set my KT controller to max out the top speed (72kmh/44mph). My bikes will make it up to ~30mph, limited by KV and voltage, so I’ve set the KT controller to have no programming limitation on top speed.

Every KT controller I’ve worked with has regen that can be enabled in the menus, along with options for regen strength.

You’re talking about jumping pins on the board— FWIW, for basic functionality, everything should be programming with the display and keypad. There’s nothing I’ve wanted to adjust on my KT controller, on my basic ebike, that couldn’t be done through the display. No pin jumping required.

I’m unsure if KT controllers will operate without the display. They need the push button key pad to turn on, which is attached to the display.

I've heard of all sorts of "problems" where people would get controllers that are limited way too low without any means to change it, and sometimes even displays interfering even more so I want to avoid that. I was under the impression that my previous controller didn't had any limits as well and that motor is limiting factor. But just few days ago after over 2 years of thinking that, I've discovered that shorting pins K2 and ground would spin motor at full speed. My controller doesn't have display or programming plugs. I've enabled regen through shorting pins as well. Before, it would stop at exactly 42km/h but it was kinda too "strictly" holding that 42 so I always found it a bit suspicious. After shorting pins, I've pushed it to 52-3 without any problems and I din't try more because it's just pointless on a bicycle. I don't need high speeds but it's good to have a option when needed. I'm just worried that I might get controller that's limited to 25kmh or something and then I don't have ways to change it. I don't need any programming options if controller has some means to change settings through jumpers / shorting or something.

As someone else mentioned, should be no problem to start it up by shorting pins on display port (usually red to green).

FYI - the parameter configurations are held in the display. There may be some you can hard wire with jumpers, but I would want more specific info if I were planning on running a KT without a display....

KT controllers all have "KT" included in the controller model number.....

I was thinking if I really have to maybe get a desplay and use it just for programming but if that's the case then it's rather pointless. Or maybe get a very very small one, but most seem to be too big for my liking... I guess that answers my question of programming through display port as well...

 

[From-A-To-B]

I've heard of all sorts of "problems" where people would get controllers that are limited way too low without any means to change it, and sometimes even displays interfering even more so I want to avoid that. I was under the impression that my previous controller didn't had any limits as well and that motor is limiting factor.

Motors will soon as fast as they can, up to the voltage your battery allows, and they will do this with as much power (amps/acceleration) as the controller will feed them.

Motors do not limit speed. Voltage limits speed and motor winds can limit relationship to voltage with regards to speed. A motor will work as hard as it can, generating increasing heat as its fed more power, until it melts down.

Just wanted to get that straight.

Controllers limit power, often by capping max amps and, sometimes, programmatically restricting top speed.

 

[c111jp]

Motors will soon as fast as they can, up to the voltage your battery allows, and they will do this with as much power (amps/acceleration) as the controller will feed them.

Motors do not limit speed. Voltage limits speed and motor winds can limit relationship to voltage with regards to speed. A motor will work as hard as it can, generating increasing heat as its fed more power, until it melts down.

Just wanted to get that straight.

Controllers limit power, often by capping max amps and, sometimes, programmatically restricting top speed.

Yup, wanted to write controller/ motor (since winding will also affect it). What I want to say is, I don't want controller to stand in the way with limiters, or at least as little as possible.

Anyway, got this controller in the meantime since it was locally available while I find a "perfect" controller. It's XLD Brainpower LSD149. If anyone have any tips for those, they are of course welcome. Seems like it should be fine out of the box but one thing I'm worried about is Low Voltage Cutout. It's written as 42V for 48V on the controller. I have 50E cells which have 2.5 voltage cutout, I wouldn't go that low but they are fine up to about 2.8 volts which is 36.4 v so I would be leaving quite a bit of capacity on the table.
Ideally I would remove LVC all together but apparently this will affect regen. I will start new topic on it so things are more organized for future readers.

 

[amberwolf]

I was under the impression that my previous controller didn't had any limits as well and that motor is limiting factor.

All controllers have limits. Some are alterable and some are not, depending on the controller. There is always a current limit (battery rather than phase for non-FOC controllers), and an LVC for protecting the battery against overdischarge. Often there is also an HVC to protect the controller itself (usualy for ones with regen, to disable the regen above a certain voltage which also protects the battery against overcharge).

The pads you found that decrease and increase speed are the "3 speed switch" wires. These normally go to a 1P2T center-off rocker switch, with ground in the center pin and the two wires to the outside pins. One of them is "low", the other is "high", and no connection is "normal". What this usually does is limit the throttle input response of the controller, and they usually call no connection 100%, and the other two higher and lower percentages by wahtever amount. Since you can't really get more than 100%, they're mislabelled this way, but it sounds cooler to the liars in the marketing departments.


Regarding programming any controller without using it's display--for those you would need the software from the controller manufacturer for that specific model and version of controller, since even a difference in firmware version on the controller could keep it from working with a different version of setup software (this also happens with displays talking to the controllers)...AND some versions of the same controller can be "locked" so that only the factory could reprogram them, no matter what setup software you happen to have. So if the site you are looking at doesnt' have the setup software and manuals on how to use that software, you should check the manufacturer website for the specific controller you are looking at, and get the SW and manuals there, including the instructions for wiring up a programming cable if it does not have a port built into the controller's cabling already. If there is nothing like that on the manufacturer site, you're on your own to research whether or not that controller even has setup software, much less finding the right version for yours, and hooking up a programming cable. There are sometimes pages here on ES or other places about specific controllers to do this, but there's no guarantee you'll find the right one this way.


If you really want to be certain of programmability beyond a display's available settings, buy from the manufacturer or dealer that actually has that stuff directly available, or go with something like the various VESC variants, ebikes.ca's Phaserunner/etc series, or the various other controller types (Kelly, Sabvoton, Votol, Fardriver, etc etc) that are fairly well documented by DIYers.

If it's a "generic" controller, odds are you won't find useful info and are going to be on your own DIYing a solution, if it's even possible.


Regarding onboard solder pads, note that the abbreviations are not consistently used across various manufacturers and brands and models, so what you find works on one may not on another. Also, the firmware on the controller may not even support some pads' functions, so they may not do anything even if correctly connected.

 

[amberwolf]

I posted this in your other thread, but since you made a whole new one for this question I'll just copy it here, too.

Anyway, got this controller in the meantime since it was locally available while I find a "perfect" controller. It's XLD Brainpower LSD149. If anyone have any tips for those, they are of course welcome.

There are some threads for XunLida / Brainpower controllers with some info, if you poke around.

Seems like it should be fine out of the box but one thing I'm worried about is Low Voltage Cutout. It's written as 42V for 48V on the controller. I have 50E cells which have 2.5 voltage cutout, I wouldn't go that low but they are fine up to about 2.8 volts which is 36.4 v so I would be leaving quite a bit of capacity on the table.
Ideally I would remove LVC all together but apparently this will affect regen.

You don't really want to run cells down that far, if you want to keep the battery unstressed and long-lasting. 3.0-3.2v / cell is the lowest I would use for a controller LVC--they're set this way to prevent potential cell damage...especially since almost no ebike battery is made of matched cells, so they don't stay balanced, and you can have some cells that are much lower than others. If you use a controller LVC (that can't actually know how low the cells are) that's at or near the actual per-cell-level LVC, then you can damage cells that are below that average voltage. Such damage is cumulative, will shorten the pack life, and if severe enough can create a fire risk.

If you are running a typical BMS on the pack, then that will help do cell-level protection, but the BMS LVC is an emergency shutdown, cutting all power to save the cells from damage. You don't use that for everyday protection, so the controller LVC is set higher on purpose, to use as everyday protection. If there is no BMS, then the controller LVC is your only protection, so setting it higher is even more important.

So for a 13s pack (48v) you'd usually use a 41-43v controller LVC. For a 14s pack (52v) a 44-46v LVC.

There is not all that much actual capacity in most cells below 3v, and some not even below 3.2v at higher currents. See the testing charts here for this cell:

Test of Samsung INR21700-50E 5000mAh (Cyan)

for some info on that; first chart copied below:

 

[c111jp]

Got reply from another seller which is selling same controller and they too said it doesn't have regen. I've decided to skip on it.

I've received XLD Brainpower one and it's going to be more than enough. It already has regen, self learning, speed connector (which is just basically bridging K1, K2 and ground), and it's same size as my previous one but it's 15MOSFET vs old one that was 12Mosfet. Fets are also rated quite higher than old ones. I have no need to program anything. I will leave LVC alone for now too.