Battery Tester based on
http://www.talkingelectronics.com/projects/30%20LED%20Projects/30%20LED%20Projects.html#71
While simulation is running, adjust power source between 3v - 4v. Red LED will light with a low voltage, green LED will light with a high voltage...
Check out my blog: https://www.rubenfixit.com/2014/05/15/cell-phone-li-ion-battery-tester
