Arduino based Battery Over Discharge Protection Circuit | Homemade Circuit Projects
How to Use a 12v Battery to Power an Arduino Uno and 2-12v Lights - #15 by groundFungus - Project Guidance - Arduino Forum
I have built a battery level indicator and have tested with a 12V battery Would it harm my arduino board if I connect a 48V battery? - Arduino Stack Exchange
Powering Arduino With a Battery (with Pictures) - Instructables