battlefield vs battleground

battlefield

noun
  • The area where a land battle is or was fought, which is not necessarily a field. 

battleground

noun
  • A location where a battle may be fought, or has been fought. 

  • Any subject of dispute or contention. 

  • Any place or situation of dispute or contention 

How often have the words battlefield and battleground occurred in a corpus of books? (source: Google Ngram Viewer )