catnap vs recharge one's batteries

catnap

verb
  • To take a catnap (short sleep or nap). 

  • To kidnap a cat. 

noun
  • A brief, light sleep, usually during the daytime. 

recharge one's batteries

verb
  • To recover mentally by taking a break or engaging in a relaxing activity. 

How often have the words catnap and recharge one's batteries occurred in a corpus of books? (source: Google Ngram Viewer )