Did I kill my mid drive controller?

[Sappho1949]

I recently changed the battery connector from a bullet connector to an xt60. I have never done this before and reversed the polarity of the male end without realizing it, so when I tried to turn on my motor (Bafang mid drive 48v 750w) nothing happened. I realized my mistake in reversing the polarity and corrected it, the tried again with the polarity corrected. This time when I turned it on, the display came on and worked normally, but now the motor barely engages, seems as if it is trying but will not engage. I am wondering if turning the motor on before I realized the wiring mistake might have ruined the controller.

 

[Gionnirocket]

I recently changed the battery connector from a bullet connector to an xt60. I have never done this before and reversed the polarity of the male end without realizing it, so when I tried to turn on my motor (Bafang mid drive 48v 750w) nothing happened. I realized my mistake in reversing the polarity and corrected it, the tried again with the polarity corrected. This time when I turned it on, the display came on and worked normally, but now the motor barely engages, seems as if it is trying but will not engage. I am wondering if turning the motor on before I realized the wiring mistake might have ruined the controller.

Well if it was working properly before... Then probably.
Have you double checked your battery connection? Is it solid? How did you connect the XT60? Crimp? Solder?
Could possibly be a poor connection that can't handle the current.

 

[Sappho1949]

Well if it was working properly before... Then probably.
Have you double checked your battery connection? Is it solid? How did you connect the XT60? Crimp? Solder?
Could possibly be a poor connection that can't handle the current.

I admit that my soldering job was pretty crappy. I had never done it before and didn’t really know how to do it properly. I put a new controller in today (never trust YouTube when they tell you “it will be so easy, 15 minutes tops”…they are lying!)
It seems to work though I am now too exhausted to do a test ride today. I will check the soldering again to see the wires are snug. Thank you for the reply!

 

[Gionnirocket]

Well hopefully you're all set.
But I know what you mean.. I got taken in by this box of Cream of Wheat.

It states that it cooks in 2-1/2 minutes... but that's after you bring the water/milk to a boil.... What a gyp!

 

[harryS]

I have done this twice, wiring up XT60's backwards in a rush, When I connected the battery to the bike, the connector pins melted instantly with a big POW/ZAP. That probably saved the controllers, DId it with a BBS02B and also a hub motor.

You must have connected the battery with it switched off. When you flipped the switch, there was nothing to prevent the battery current from flowing backward thru the motor transistors.