motor controller advise needed

jon h spain

Finding my (electric) wheels
Aug 19, 2021
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hi, can anyone advise please.my wifes 3 wheeler electric keeps cutting out on the way up the hill to our house.we had a new battery put on last year and battery is showing 39v on a 36v so not bad.the lcd display is intermittent and so i think it might be the motor controller.i have tried to look for a new one, the old one had kt36zws - 11060619 brushless dc motor on it, but no manufacturer name on the controller itself.the new battery was a lithium ion 36v 9 amp battery.i cant find a controller with anything like the same wiring configuration or plugs, help, anyone any ideas, its not funny pushing a 3 wheeler in 42 degrees, best wishes
 

Nealh

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Kt36zws is a KT controller, company is Kuenteng, China. KT are commonly available stuff and the best non oem controller system available widely.

Your cutting out issue may not be controller but battery related.
What is the current rating stated on the controller label ?
What is the continuous current rating of the battery ?

Also you say battery reads 39v, what is the max voltage hot off the charger when full ?
 

jon h spain

Finding my (electric) wheels
Aug 19, 2021
11
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Kt36zws is a KT controller, company is Kuenteng, China. KT are commonly available stuff and the best non oem controller system available widely.

Your cutting out issue may not be controller but battery related.
What is the current rating stated on the controller label ?
What is the continuous current rating of the battery ?

Also you say battery reads 39v, what is the max voltage hot off the charger when full ?
 

jon h spain

Finding my (electric) wheels
Aug 19, 2021
11
0
Hi neal, thankyou for your reply, most kind frustratingly I don't know the current rating of the controller as the label has rubbed off, see picture. The battery is just marked as 36v 9amp, again pictures attached. As the battery was new, and the controller rubbed off, I assume the bike shop that replaced the battery didn't replace the controller, as the label is worn. What happens when riding the bike is that the lcd display(that was new simultaneously with the battery) starts disappearing when you put some serious demand on it(the hill) and just cuts out completely. I have just started charging the battery, to see its charged voltage, and will let you know, really appreciate your advice
 

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Nealh

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The issue is a likely a battery one as the bike works, controllers either work or they don't. The fact the display fades indicates a power issue and again it is the battery that supplies the power.
You could try and rig up a volt meter so you can read it and see what happens to the voltage riding up said hills, if it shows a sharp decline in volts or a voltage collapse then the battery is poorly or can't supply the power which controller ask's for.

Let's see what the full charge is.
 

jon h spain

Finding my (electric) wheels
Aug 19, 2021
11
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Hi neal, thankyou for your reply, most kind frustratingly I don't know the current rating of the controller as the label has rubbed off, see picture. The battery is just marked as 36v 9amp, again pictures attached. As the battery was new, and the controller rubbed off, I assume the bike shop that replaced the battery didn't replace the controller, as the label is worn. What happens when riding the bike is that the lcd display(that was new simultaneously with the battery) starts disappearing when you put some serious demand on it(the hill) and just cuts out completely. I have just started charging the battery, to see its charged voltage, and will let you know, really appreciate your advice
 

Nealh

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Aug 7, 2014
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Until Jon h has clarified the full charge voltage we won't know, he mentioned 39v but it isn't clear whether this is a discharged or charged voltage.
 

jon h spain

Finding my (electric) wheels
Aug 19, 2021
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The issue is a likely a battery one as the bike works, controllers either work or they don't. The fact the display fades indicates a power issue and again it is the battery that supplies the power.
You could try and rig up a volt meter so you can read it and see what happens to the voltage riding up said hills, if it shows a sharp decline in volts or a voltage collapse then the battery is poorly or can't supply the power which controller ask's for.

Let's see what the full charge is.
Brilliant, I will leave it on all night and let you know, most kind
 

jon h spain

Finding my (electric) wheels
Aug 19, 2021
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In reply to neal, sorry for late reply, I did as you said, and gave it a long charge, and it ended up ay 41.9 volts, but from previous experience with the bike, I haven't any faith in its strength. Could I theoretically take the 36v battery off my tried and trusted 2 wheeler and connect it to my wife's 3 wheeler, also li-on. At least I would know for sure it was the battery. The link from my wife's battery to controller is a circular bayonet connector, with 2 red and 2 yellow feeds, thanks for your information and time, for example with the controller either working or not working. Last question, the led controller, could there be a compatiblity problem, as when the shop changed the battery, they also changed the led controller, which controls strength, distance, shows battery capacity, turns on and off(even though it not showing correctly, as when the bike packs up on the hill, the led still says battery full, muchas gracias
 

Nealh

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It is possible the LED and controller aren't compatible depends if the LED was analogue or digital also similar looking and model number LED's aren't all the same compatibility wise as it depends on the make brand.

Recently someone had an issue with a LED 880 or 890 and bought a replacement, it didn't work. He had a KT controller and bought a LED that wasn't KT so the software/programming was wrong.
 

jon h spain

Finding my (electric) wheels
Aug 19, 2021
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It is possible the LED and controller aren't compatible depends if the LED was analogue or digital also similar looking and model number LED's aren't all the same compatibility wise as it depends on the make brand.

Recently someone had an issue with a LED 880 or 890 and bought a replacement, it didn't work. He had a KT controller and bought a LED that wasn't KT so the software/programming was wrong.
 

jon h spain

Finding my (electric) wheels
Aug 19, 2021
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Thanks for that, so what you are saying is, if I get a kt controller, it will definitely likely be compatible. I posted a picture of the controfller, is there any chance that you could have a look at the picture of it, and recommend a new controller, sorry to ask so much of you, regards, jon h
 

wheeliepete

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As the LCD1 remains on when bike cuts out, it's unlikely to be a battery problem. It's poss. the controller is cutting out due to thermal overload from a combination of high current demand on the hill and high air temp. Assuming the controller is in some sort of container, if poss. you could try exposing it to open air for a test run.
 
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jon h spain

Finding my (electric) wheels
Aug 19, 2021
11
0
As the LCD1 remains on when bike cuts out, it's unlikely to be a battery problem. It's poss. the controller is cutting out due to thermal overload from a combination of high current demand on the hill and high air temp. Assuming the controller is in some sort of container, if poss. you could try exposing it to open air for a test run.
 

jon h spain

Finding my (electric) wheels
Aug 19, 2021
11
0
The led controller cuts out repeatedly when on "the hill" even though the battery is showing full, and even when on, its screen is faded and sick, I will do as you suggest and give the bike a try with the motor controller open to air
 

Nealh

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The lcd1 lools like and is marked so a so genuine KT lcd1 it is digital so should be ok.

The bike cutting out then as battery appears to be ok could be as Pete say's due to heat and the hills, more so if the hills are climbed at slow speed with max power PAS5 or throttle. I had a similar occurrence a few years ago with my KT, the the lcd3 going blank and then after a while coming back on.
The culprit I found was the controller, it was hotter then a hot potato and the mosfets thermally cut out reaching their max temp. Once cooled the controlled was ok again until the next ascent.
Initially I remedied the issue with extra heatsink and small cooling fans but tired of the extra small battery charging and time to set up, in the end I replaced the controller box with a KT 9 mosfet sensored controller instead of the 6 mosfet one.
 

wheeliepete

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Your display is an LCD screen and could well be reacting to the 42 degree heat. Living in the UK, I've not used my bike in such temps. so it's a bit of a guess, but unless it goes completely blank, the screen is still getting power, which means the controller is cutting power to the motor.
 

Nealh

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Before you move the controller in to the open air, test once more so it cuts out and feel how hot the controller gets. If it is untouchable then mosfet thermal cut out will be the issue.