Controllers Failing and Recommendation?

[faithblade]

I bought a cheap 72v 3000w motor Amazon kit and had a 72v 40ah battery that supposedly does 100a continuous and 300a peak. The first controller from the cheap kit fried and I replaced with with a Kelly KVD7212nx that should be 75a cont, 200a peak and the green phase mosfets shorted. Im thinking the 2nd may have been defective but who knows.

What gives? Im extremely unknowledgeable in this electric stuff so please don't be too harsh on some of my dumb decisions and could use a recommendation on a controller to pair with my battery.
Also, the battery has no discharge bms (sketchy and unadvisable, I know) so could anyone help me out on controller settings that won't make my bike burst into flames?
My bike has just been electrical problem after mechanical problem and I've lost motivation dumping money and time into this thing for the past year, but it is bliss whenever that short period where it works happens. Thanks in advance for any advice and help guys.

 

[E-HP]

Does the controller have good airflow where it's mounted?

 

[Chalo]

I have run across one case of a motor that killed every controller that was plugged into it. I never bothered to take it apart and try to figure out why it did that. I assume it must have been a short somewhere.

Maybe you can check impedances between the wires going into your motor and see if any of them shows a dead short when it shouldn't. (Phase to phase will probably show continuity even if it's working normally.)

 

[faithblade]

Does the controller have good airflow where it's mounted?

The airflow is not the best but the controller doesnt get hot

 

[E-HP]

The airflow is not the best but the controller doesnt get hot

How quickly did they fail and under what circumstances (normal riding, climbing a hill, shut off then wouldn't repower, etc.)? Do you have a link for the Amazon kit?

 

[faithblade]

How quickly did they fail and under what circumstances (normal riding, climbing a hill, shut off then wouldn't repower, etc.)? Do you have a link for the Amazon kit?

It was a slight incline after a few minutes of riding. The motor was decently hot and I heard a popping noise. The bms discharge short circuit protection got tripped I think. The battery is now bypassed and working outputting 84v instead of 39 through the bms. I think the mosfet in the controller shorting tripped the bms.
Here is the kit, only thing in use is the motor after the controller died a long time ago randomly right after turning on the bike, it moved a foot and died.
VEVOR Electric Brushless DC Motor,72V 3000W Brushless Electric Motor,4900RPM Brushless Motor Kit,w/Controller and Throttle Grip for Electric Scooter E Bike Engine Motorcycle DIY Part Conversion Kit https://a.co/d/5p07PYC

Im getting a refund for the controller so I can hopefully get another that handles the battery and can set the amp limit and stuff. But I need a recommendation on that.