Help! Conversion kit won’t turn on

[sid0000]

My conversion kit stopped turning on, when turning it off the motor springs slightly and the wheel vibrates when spinning now. the battery level indicator on the battery doesn’t light up anymore either. any help would be great

 

[saneagle]

My conversion kit stopped turning on, when turning it off the motor springs slightly and the wheel vibrates when spinning now. the battery level indicator on the battery doesn’t light up anymore either. any help would be great

None of what you wrote makes sense. It won't turn on. How do you turn it off, then? How does the wheel do anything if it has no power because you can't switch it on?

I think it might help if you slow down and start from the beginning:
Which kit is it?
How long have you had it and how much have you used it?
How did your problem start? What happened just before it started that caused the problem?

 

[sid0000]

None of what you wrote makes sense. It won't turn on. How do you turn it off, then? How does the wheel do anything if it has no power because you can't switch it on?

I think it might help if you slow down and start from the beginning:
Which kit is it?
How long have you had it and how much have you used it?
How did your problem start? What happened just before it started that caused the problem?

I don’t know what motor i have but it is a 27.5 1500w with two silver lines around the rim.
48v 15aH battery
kt lcd3
The screen doesn’t turn on but when I turn the switch on the battery on and then off the motor twitches (which also locks the wheel for a split second). When this first happened the screen displayed normally for a couple seconds until all of the icons for a second and then only displayed “info”, i’m not sure what word to use but the motor was acting like when going up a hill at a low power and it cuts out while this was happening. After it did this the screen turned off and it did the same thing when turned back on, this happened about 4-5 times until the screen stopped turning on completely and the motor stopped working.
When i said the motor spinning i meant when moving it with my pedals, it also is now very hard to move and feels as if the brakes are on which they are not. The back wheel feels as if they are bumping up and down.
Nothing in particular happened when this occurred i just turned it on and it happened. I have had it since 2017 but barely had any issues so far. The only thing i have noticed that has visibly changed is that the front brake sensor cable was exposed but it was not wet when it had broke.

 

[saneagle]

I don’t know what motor i have but it is a 27.5 1500w with two silver lines around the rim.
48v 15aH battery
kt lcd3
The screen doesn’t turn on but when I turn the switch on the battery on and then off the motor twitches (which also locks the wheel for a split second). When this first happened the screen displayed normally for a couple seconds until all of the icons for a second and then only displayed “info”, i’m not sure what word to use but the motor was acting like when going up a hill at a low power and it cuts out while this was happening. After it did this the screen turned off and it did the same thing when turned back on, this happened about 4-5 times until the screen stopped turning on completely and the motor stopped working.
When i said the motor spinning i meant when moving it with my pedals, it also is now very hard to move and feels as if the brakes are on which they are not. The back wheel feels as if they are bumping up and down.
Nothing in particular happened when this occurred i just turned it on and it happened. I have had it since 2017 but barely had any issues so far. The only thing i have noticed that has visibly changed is that the front brake sensor cable was exposed but it was not wet when it had broke.

You have all the symptoms of a short circuit between the controller and motor - probably a blown MOSFET in the controller because you can't switch on. The battery will switch off when it detects that problem. The other possibility is that the motor wires have melted where they come out of the controller and are now touching, but that wouldn't stop the battery switching on; however, if the melted wires touch each other, it would probably blow the MOSFETs, so you'd end up with both problems.

Disconnect the motor from the controller, and the motor should turn freely. That would mean that the short circuit is between the remaining wires and the controller. If the motor is still stiff, the short circuit is in the cable attached to the motor.

Let's summarise that.
1. If the short is because wires have melted, you'll see it when you try to disconnect at the controller end of the cable.
2. When you disconnect the motor cable at the controller end and the motor is still stiff, the problem is in the cable
3. When you disconnect the cable at the controller end and the motor frees up, the problem is in the controller.
4. Whichever of those things caused the problem, it's pretty certain that you have blown MOSFETs in the controller, so that will need to be replaced.

There's a simple test you can do for the MOSFETs if you have a multi-meter.

 

[Az.]

I don’t know what motor i have but it is a 27.5 1500w with two silver lines around the rim.
48v 15aH battery
kt lcd3

It is a good thing that your e-bike is broken. It is in best interest of our community to keep your bike away from people.

 

[saneagle]

His battery must have a decent BMS, which is cutting off the battery when there's a short, otherwise there would have been another BBC news article. It just goes to show that even the standard Chinese parts are good enough to avoid disaster. The problem is when they don't use established components and methods.