Nightmare after a ride in the rain

[curly funk]

Hi guys,


The rain caught me while I was heading back home from work, and it was heavy. I decided to go full throttle until I got to my house. Unfortunately, a few kilometers from home, my motor stopped — no throttle response, no PAS.


I switched off the battery and pushed the bike home. Then I removed the battery and left it there. The next day, I took off the saddle to check what was happening with the controller. There was still water at the bottom of the box where the controller is located. I also noticed that the power cables to the motor were burned. I left the bike in the sun to dry thoroughly, and the next day I tried to cut off the burned parts of the cables and reconnect them, hoping it would fix the problem. No success.


What I saw was that my LCD shows no errors, but when I pull the brakes, there is no indication. The headlight and turn signals work fine. Anyway, I removed the battery again, and when I started pushing the bike back into the garage, the hub motor started making a rattling sound — it happens only when I push it backward. Then I unplugged the hub connector and saw that a few of the holes on the female part were slightly melted. I tested the thick male pins with a multimeter and got 0.00.


I've been riding bikes and motorcycles all my life, but I have no clue about electronics. Also, there is only one e-bike service shop near me, and I don’t really trust that they know what they’re doing. From what I’ve researched online, I think I will need to replace the LCD, controller, and hub. But if someone could give me instructions on how to properly test everything to see what is damaged and what isn’t, that would be great. Or if someone can suggest a kit to buy that won’t cost me a kidney, that would be awesome.


Thanks, guys!

 

[fechter]

There is a freewheel clutch inside the motor so the rotor only spins if you push the bike backward. Try unplugging the motor from the controller and see if the rattling noise is still there. If a controller FET is shorted, it will make the motor hard to turn. You may need to take apart the hub to inspect inside.

You can use a multimeter to check for shorted FETs in the output of the controller. Unplug battery, measure ohms between each phase wire (the 3 fat pins) and battery positive, then again to battery negative. Reverse the meter probes on each measurement. A shorted FET will look like zero ohms in both directions. A good FET will look like a diode.

 

[curly funk]

There is a freewheel clutch inside the motor so the rotor only spins if you push the bike backward. Try unplugging the motor from the controller and see if the rattling noise is still there. If a controller FET is shorted, it will make the motor hard to turn. You may need to take apart the hub to inspect inside.

You can use a multimeter to check for shorted FETs in the output of the controller. Unplug battery, measure ohms between each phase wire (the 3 fat pins) and battery positive, then again to battery negative. Reverse the meter probes on each measurement. A shorted FET will look like zero ohms in both directions. A good FET will look like a diode.

Thank you so much for taking the time to reply. When the controller is disconnected from the hub there is no sound and I can push it freely. And the yellow cable is giving me 0.00 on positive and 0.006 on negative. The green and blue are sending around 0.008/9 in both ways. Does this mean that I must get only a new controller?

 

[fechter]

Be sure you are measuring Ohms, not volts with the meter. A shorted FET means you need a new controller.

 

[curly funk]

Be sure you are measuring Ohms, not volts with the meter. A shorted FET means you need a new controller.

yeah, I measured in Ohms. Ordered new controller, will update next thursday, thanks a lot!

 

[Mclewis1]

While waiting for your new controller I'd go over all your cabling and connectors. Carefully clean the battery connectors and the motor connector (paying particular attention to those 3 larger phase connections). Then I'd put a little bit of dielectric grease on all the pins in each connector and re insert them. I might also tape (using black electrical tape) each connection or at least the cabling to the motor.

I'd also take a good close look at where your controller is mounted to see if you can seal it up a bit better. I'd use some silicone caulking in any obvious gaps.

Once a year on my bike I check and re do the dielectric grease and tape. This seems to help prevent any future moisture problems.

 

[fechter]

Good points.
It seems water got into something that it shouldn't have. Any connectors or places where wires enter need to have some provision for keeping water out.