Does anyone have experience converting this bike with a mid drive Bafang or Tongshang? My worry is the battery won't fit in the frame...its not a large space. Any suggestions?

Second question. I have a rad power city with a 14 AH 48V battery? Is this battery compatible with a Bafang or Tongshang conversion?

Thanks for the help. Looking forward to ride with my son on some mtb trails. 😀