Short in brake cut off. Burnt sensor wires fix?

[CaliClouds]

Hello guys. I put a 1kw front hub motor kit on our Schwinn meridian trike. It was wonderful for a couple weeks and got a couple hundred miles of use without the supplied brake cables or PAS parts.

I installed the supplied brakes to see if the kit provided regenerative braking and as soon as I turned on the power to the bike I heard a pop and smelled burnt electronics. I suspect the brake cut off switch had a short to ground. The wire for the brakes was visibly burnt as was one of the two sensor wires going from the motor to the controller. The connecters partially fused together. I opened the controller ànd everything passed a visual inspection. I do have a multi meter handy for testing but I'm not sure what to check.

So I'm not too knowledgeable on ebikes but I'm guessing I burned a sensor on the motor. I would be fine with purchasing a sensor less controller if it's that easy. Do you guys have any idea what I may have damaged? The LED indicator lights work and show power but twisting the throttle results in no response.

Thanks guys! Within an hour I ordered another kit because I hate driving now!
-Jon

Edit: figured I should attach a picture on my first post here. 2x 5amp 20c turnigy batteries (not recommended) 1kw generic eBay hub motor. 26 inch tires. Twist LED throttle

 

[amberwolf]

I installed the supplied brakes to see if the kit provided regenerative braking and as soon as I turned on the power to the bike I heard a pop and smelled burnt electronics. I suspect the brake cut off switch had a short to ground. The wire for the brakes was visibly burnt as was one of the two sensor wires going from the motor to the controller. The connecters partially fused together.

Normally there are only two wires on ebrakes, so a short would be normal for when the brake is engaged.

Even if you had the 3-wire type, that uses a hall sensor in the lever instead of a switch, even a dead short across all three wires wouldn't cause that kind of damage.

It is much more likely that the brake levers were plugged into the wrong connector on the controller. There are often plugs on controllers that have full unfused/unlimited-current battery voltage on them, and shorting that to ground or something else could easily cause that kind of damage.

If the battery voltage was applied to a 5v line, it could destroy anything else attached to 5v, which includes hall sensors in throttle, motor, and the MCU (heart of controller), possibly gate drive to the FETs, etc., as well as the actual 5v regulator inside the controller.

It may not have destroyed all of that stuff, but it might have.

First, you can use the voltmeter to measure what voltage is actually on the two wires that come from the controller (that the brake was plugged into). Use the black wire from the meter to the battery negative, and the red wire to measure each of the two wires.

Then you can use the red wire to measure each of the other wires from the controller, and see what voltages each has on it. That will tell you if the 5V is still working at all--if it isn't, it could be because something else is shorting it out (dead sensors/etc) or that the 5V regulator simply blew up...or because everything connected to the line is dead.


There are some other helpful tutorial/etc type threads in the "Sticky Index" threads in each subforum, and in the ES wiki http://endless-sphere.com/w

 

[dogman dan]

At this point, it might be worth while to get a motor controller throttle tester on ebay, so you can at least confirm the motors halls are ok.

Try for a complete kit replacement from the vendor. IMO, you didn't do it mixing up the wires. I think you just got lucky. They do zero QC on kits that cheap.

 

[CaliClouds]

Ah that makes sense now. Thanks guys. I definitely burned the constant power lead. I'll check with the vendor and see what I can do. If they can't help Im pretty good with electronics so hopefully I can salvage something for a hot rod project.
Thanks again!

 

[CaliClouds]

Oh and thank you for the recommendation on the motor tester. I didn't know they existed so I ordered one. A few people want an electric bike now so I'll be building a few more. That will really come in handy.