TWO QUESTIONS: 1. I KEEPS BLOWING MOSFETS ON CHINESE CONTROLLER NO LABEL 2. EB206 DIED AFTER PLUGGED 80V BATTERY

[sensi]

Hello,

I HAVE TWO QUESTIONS I NEED HELP

Question 1
I am just getting into Ebike world, Made my own scooter frame. I was using a 6fets EB206-A-5 board controller, I don't know the controller name. I was just given while in not working condition.
Managed to change some resistors and mosfets and voltage regulator then it worked. I used it on 64V for a week, Later a friend brought a 2000w chinese controller without a name. we tried it and was not faster than my 6fets controller. In comparison I forgot we were on 80V, connected my 6fets controller and instantly heard blown sound and smell. 5V regulator and LM317 brow. Replaced them but no luck LED shows cobntroller on but wheel not spin. My question is, Is possible that MCU blow too?
https://imgur.com/Dq6NwPa





Question 2
I forgot about my 6fets controller, rigged a 2000w controller with my 1000w wheel tested fine few times.
I went out for testing. I got on it started moving for few meters at low speed and BR BR BR coog cog my wheel stalls stops like brakes.I knew this was a mosfet blowing. I replaced the mosfet. I moved with it for few times a distance of about 2KM but its was like am on 350w system or 250w very slow on gear 2. next i moved for a KM and again mosfet brow. I went back replaced all the mosfets. I went out again just few meters, this time after the wheel stalls the battery also instantly ONE cell got hot and brow with smoke.
I have been making sure the mosfets are not touching the heatsink.
Does any1 understand what is happening, Please help me.

 

[E-HP]

I have been making sure the mosfets are not touching the heatsink.

What do you mean by this?

 

[sensi]

When I replaced the mosfet, I made sure the screw is isolated from making contact with mosfet drain. by testing with multimeter.