Upgrading KT controller, unsure how to wire it up to LCD3

Hi,

I'll soon be replacing my square wave controller (kt48zwsrl-zc21) with a sine wave controller (kt36/48svprk-sls02e), but while both are from KT and are compatible with the LCD3, they don't have the same connectors.

My current controller have battery, PAS, a 9-pin connector for the motor, and an "unknown number" (can't remember how many) multi-pin connector for the LCD3, throttle and brakes (i think, but brake switch is not in use anyway).

The new one have the stock jungle of wires and connectors that we see all the time, and so i've been able to identify almost all the connectors, but i'm still not sure if i understand how to connect it all. The PCB is marked KTE-18s5.
Take for example the cruise wire - this is something i've normally controlled by holding down one of the buttons for the LCD3, and the same goes for controlling the lights.

I plan to replace most of the current wires on the controller, and at the same time i'd like to remove whatever wires will not be in use anyway.
From what i can see the LCD3 comes with a 5-pin waterproof connector, but i can't seem to find this connector anywhere?
I'm guessing i would need an 8-pin connector between the LCD3+throttle and the controller, and 2 (or 3?) more pins if i want regen and brakes switch as well?

Could someone please explain how i wire it all up? Also, as i still have some unidentified wires on my controller, does anyone happen to have the wiring diagram for my exact model?

It seems to me that your first controller used a what they call a 1-4 waterproof cable, which is a integrated harness with two brake connectors, a throttle, and the LCD3 plug on one end, and a single round connector on the other. Usually found on manufactured ebikes.

Your second controller has the usual KT jumble of mixed connectors. These would go to the handlebars. A 5 pin for LCD3. A 3 pin for throttle. Two 2 pins for brakes. Results in four cables running up to the handlebars, plus the bulky connectors by the controller. Kit builders usually get this. I would say you're downgrading your controller, as far as connector quality.

On your first controller, cruise you probably didn't have to connect wires to enable cruise or regen. On the second one, there will be two pairs of wires you have to connect together to enable these operations. You also have to set parameters C7 for cruise and C13 for regen in the LCD3.

How to fix this? One way is to buy a new throttle, LCD3 and brake levers with connectors that fit the 2nd controller. Another way is to keep your LCD3 and throttle and cut that integrated cable to put connectors on it. Third way is maybe buy something like this. This one comes from Jue Shai on aliexpress and maybe they will sell it separately. You might have to verify the connectors.


https://www.aliexpress.com/item/36V250W-48V350W-Electric-Bike-Controller-Set-Sine-Wave-S900LCD-Display-PAS-Waterproof-Cable-for-Electric-Bicycle/32980289929.html?spm=2114.search0104.3.116.2234630a9b9DSX&ws_ab_test=searchweb0_0,searchweb201602_10_10065_10130_10068_10890_10547_319_10546_317_10548_10545_10696_453_10084_454_10083_10618_10307_537_536_10902_10059_10884_10887_321_322_10103,searchweb201603_51,ppcSwitch_0&algo_expid=8f653f84-1b47-4464-9b0e-191045713e58-15&algo_pvid=8f653f84-1b47-4464-9b0e-191045713e58&transAbTest=ae803_3

Thank you very much for the info!

I agree it's a downgrade as far as the connectors go, but it's an upgrade from square to sine, as well as from 12x STP80NF70 FETs (68 V, 0.0082 Ω, 98 A) to 18x IRFB3306 FETs.
The current controller is shunt modded, so they will deliver the same power, but I'm thinking sine will be better, as well as sharing the load over more and better FETs...

So if i'm understanding it right, as long as the cruise wires are shorted on the controller, i can control it like normal trough the LCD3? If so, no problem, then i just solder them together internally and remove the wire. Is it the same with the light option? The way i have it now i push and hold the UP button to turn on the LCD back-light.

As for your solution options, option 2 appears to be the best. I intend to replace several or most of the wires on the controller anyway, so might as well just replace them all and put on a new connector that covers all the wires to the handle bar. If i understand you correct a 10-pin connector would do(or 8-pin if i skip the brake sensor wire)?

When speaking of the external lights, I never hooked mine up, I cut the wires off inside the controller and insulated the ends. I also don't use cruise or EABS. Removed them too.

And, yes, pushing the up arrow will turn on backlighting on the LCD3. I recall it also can activate walk mode if the bike is not moving, which I have used to test that the motor works when there is no throttle connected.

Yes, if you splice the main harness inside the controller, the connections are well protected mechanically. You still can unplug the LCD and throttle too. If you are lucky, the wire colors inside the cable will translate into what the 2nd controller uses.

If it is the same as my controller you need to connect the wires for cruise if you want it without pushing the button on the lcd3. Then it comes on by itself if you keep the same throttle for a while. If you don´t connect the wires you can still turn it on on the lcd3.
I have kind of a wiring diagram for a 18fet, it says at least what the different connectors are for. I found it in one of the pictures of the controller from a seller on ebay.

Here's a diagram of the colours and connections. The one at the bottom is the connector on the controller as you look into it, and the top ones are the one into four cable as you look into the connectors. "Controller power" is the switched wire that provides battery voltage to the controller's pcb.

Sorry, It won't accept the attachment. Send me a pm with your email if you want it

I ended up cutting the connectors off and making new connectors and everything ended up fine, with the exception of PAS.
PAS sensor is connected, and the LCD3 is unchanged when it comes to settings, but there is stil no response when turning the pedals (regardless of direction).
The PAS connector is still original, so it's unlikely that it have anything to do with the new connectors i've put on. I switched back to the previous controller, and PAS works fine again. Any idea where to start troubleshooting this?

Also, does anyone know if it's save to go from a 48V to a 52V battery on the KT controllers and LCD3 without any modifications (i'm aware battery indicator will be off, that's no problem)?

I occasionally put a 52V battery on my KT 36/48xxxx controllers. They work, but I believe the LVC remains set for 40V. a little low for a 52V pack. The latest controllers have a L screen that appears after the C14 parameter if one mistakenly pushes up/down. Someone said that is used to further adjust LVC.

As for your PAS, verify that the power/ground pins in the connector you added are the same as the other controller. Check for 5V too. Maybe tug on the wires too, if you crimped new pins into the JST. I don't think there is any way to turn off PAS in the C settings, but maybe you can clear them to default in case there is stray data in the registers. I bought a cheap dash camera for my bike the other day and it wouldn't record out of the box. Too late to send it back, but did a reset and then it worked. Odd.

docw009 said:

I occasionally put a 52V battery on my KT 36/48xxxx controllers. They work, but I believe the LVC remains set for 40V. a little low for a 52V pack. The latest controllers have a L screen that appears after the C14 parameter if one mistakenly pushes up/down. Someone said that is used to further adjust LVC.

Click to expand...

On my LCD3, C14 is “Power Assist Tuning”. It changes the level of assist for a given setting (weaker, general, stronger). Mine seems to have more recent firmware since the max speed goes up to 99 instead of the 70 I see on most videos. I’m running 52 volts on at KT36/48 some wave controller, but rely on the BMS for LVC (actually I use the voltmeter, with the BMS for belt and suspenders.



Sent from my iPhone using Tapatalk

Regarding the inop PAS, I discovered that there were different setting for having the sensor on the chain side of the crank vs. the opposite (left) side. The sensor sees the magnets moving in opposite directions depending on which side they are mounted on. I remember that if the sensor is mounted on the chain/right side, you need to use one of the higher settings. If on the left side, one of the lower settings.

Jan-Erik-86 said:

The PAS connector is still original, so it's unlikely that it have anything to do with the new connectors i've put on.

Click to expand...

I wouldn't assume that the PAS connector uses the right wiring sequence. I recently switched from a regular KT PAS sensor to a KT dual hall sensor, which I couldn't get working. Same thing, seemed like a simple swap. On my controller the pins go positive, negative, signal wire. The new KT PAS had the signal wire in the middle, so I needed to swap two pins.

https://endless-sphere.com/forums/viewtopic.php?f=2&t=99792&p=1461224#p1461224

My controller is the KT36/48SVPRK-SLS02G, so not sure if their is a difference between it and your SLS02e.

E-HP said:

Jan-Erik-86 said:

The PAS connector is still original, so it's unlikely that it have anything to do with the new connectors i've put on.

Click to expand...

I wouldn't assume that the PAS connector uses the right wiring sequence.

Click to expand...

Thank you for the heads up on this. I just assumed they were standard from one KT controller to another, so i have not checked it. I will have a closer look at it when able.

Just an update here; The pin-out for the PAS connector were indeed different on the two KT controllers. Swapped wires and PAS works perfectly!