title: How do I convert battery voltage into battery percentage on a 4.15V Li-Ion Battery in an Arduino IDE? (I am making some kind of LED Battery Indicator)
body: <p>I know that battery discharge on a 4.15V Li-Ion is not linear, so I would like to have some equation that I can apply in my code to show the correct battery percentage. </p>
  
  <p>I can't find any good resources on doing this in an Arduino IDE. (Help with link if you guys have)</p>