Disaster

[twincle]

My fault for trying something I know little about

I have been looking for a throttle type ebike for a while to use privately. Fully assembled have a pricetag that appears phenominal, so decided on the self buils conversion. Did a bit of trawling around the internet for a kit and it was about this point it goes down hill
I found AliExpress and after a lot of prodding around found this: https://es.aliexpress.com/item/4000410025246.html?spm=a2g0s.9042311.0.0.577963c0d0qOL1 , thought 'what could go wrong'. Initially ok then they wanted another £90 to ship from germany and after a couple of months it arrived. I installed it on my existing bike and took it for a spin. Luckily didnt get too far as it conked out. wheeled it home with an 'Error 10' showing.
Searched font of all ebike fixes, google & youtube, and tried a few of the mentioned 'fixes' to no avail - nothing nudda zilch was now happening. I opened up the controller bag to find the wire from the controller to motor had......melted
Now I have contacted seller, opened a dispute etc but contact is slow due to time zones, but I am more interested if this is still fixable and if so how. So I found the forum that could help and post here

 

[vfr400]

I've been working on ebikess for 11 years, and I've never seen anything like that. My first suspicion is that the motor cable was damaged either by pour routing or a cable tie pulled too tight. If you go down the wire towards the motor and stop at the last place where the wires show signs of melting, that would be the place where the damage occurred. Put it back like it was when you first installed it and see where that position is, which might give a clue to how it happened.

If the hall sensor wires touched one of the phase wires when the insulation was melted off, both your controller and motor will be knackered, so check the thin wires to see if they're missing any insulation. If they're all still intact, the motor should be OK, but there's a good chance that mosfets in the controller have blown. You'd have to do a resistance check on the wires to confirm that.

One other thing that can overheat wires like that is going too slowly with full power on, like going up a steep hill. Normally, the wires melt between the controller and the first connector, which would be that yellow monstrosity. The reason they burn there is because they use cheap PVC covered wires on the controller, but expensive PTFE covered wires in the motor cable, which can carry at least 30 amps, even though they're thin. I can't se from the photor what type of wire is in your motor cable. Can you confirm?

 

[twincle]

I can't se from the photor what type of wire is in your motor cable. Can you confirm?

Is that more helpful or am i missing the point?

All the wires except the thin red and yellow have melted

 

[twincle]

also Ive opened the controller and can see no burnt out spots anywhere.

Is there any way to test the motor to find out if its knackred

 

[vfr400]

also Ive opened the controller and can see no burnt out spots anywhere.

Is there any way to test the motor to find out if its knackred

Have you got a meter because you can't find out anything without one?

 

[twincle]

Have you got a meter because you can't find out anything without one?

I do but not overly familiar with all its uses - a Fluke 1587

 

[vfr400]

Start with the controller. Disconnect the motor cable. With the controller switched on and only the battery and control panel connected, confirm that you have battery voltage on the battery connector while connected, then check whether you have 5v on any of the thin reds going to the pedal sensor, throttle or motor hall sensors. To do that you set the meter to volts DC and a scale that can go up to at least 60v (normally 200v). Put the black probe on the black battery wire and keep it there, while you measure the other wires with the red probe.

Next set the meter to measure resistance of at least 50k (normally 200k) and disconnect everything from the controller, then measure between the black battery wire and each of the three motor phase wires. Repeat the three measurements using the red battery wire. Each group of three should be the same as each other and in the range 7k to 30k.

Do those measurements and report back the results.

 

[vfr400]

Is that more helpful or am i missing the point?

All the wires except the thin red and yellow have melted

PVC is normal wire insulation. PTFE insulation is much thinner and very slippery. Your photo doesn't show which type you have. Is the blue wire more or less intact, or did it peal like the other two?

 

[twincle]

Is the blue wire more or less intact, or did it peal like the other two?

The peeling is all caused by me pulling the melted wires apart by hand. The only two wires not damages are the thin red and yellow

 

[vfr400]

The peeling is all caused by me pulling the melted wires apart by hand. The only two wires not damages are the thin red and yellow

You didn't answer the question.

 

[twincle]

You didn't answer the question.

sorry it peeled like the rest

 

[twincle]

Apologies for not getting back sooner. Your help really was appreciated but as I went to explore the paths offered from you I thought to myself why on earth should I. So expecting an uphill struggle with a chinese company, aliexpress and looking up my credit card t&c's for cover, I sent it all back. Unbeknown to me I bought the package with a special free return process and utilised it after speaking to aliexpress. And against the perceived odds, had a full refund in my account some four or five days later....phew
Thank you again though!