Battery charging noise

[JPhill60]

The noise started the last time I super charged M3-was 11/21/2021. A loud popping noise would come from the back of vehicle. Drove to work 11/22/2021 plugged in car to charge-24 amp circuit at 20 miles per hour and heard a loud pop coming from car. Went out and checked car and check app on phone all seems fine. Was wondering if anyone else had same problem? Or knowledge of such things happening. Something I should take car to get checked?

 

[Zextraterrestrial]

metal sheet between battery and the car flexes when the temperature changes. like a cold baking pan put in a hot oven.
supercharging always does it to mine. it's the floor area of the rear seats I think, you can bang it from the inside and it makes noise similar

 

[JPhill60]

Thank you. No need to worry.